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This allows the RETURNING list of INSERT/UPDATE/DELETE/MERGE queries to explicitly return old and new values by using the special aliases "old" and "new", which are automatically added to the query (if not already defined) while parsing its RETURNING list, allowing things like: RETURNING old.colname, new.colname, ... RETURNING old.*, new.* Additionally, a new syntax is supported, allowing the names "old" and "new" to be changed to user-supplied alias names, e.g.: RETURNING WITH (OLD AS o, NEW AS n) o.colname, n.colname, ... This is useful when the names "old" and "new" are already defined, such as inside trigger functions, allowing backwards compatibility to be maintained -- the interpretation of any existing queries that happen to already refer to relations called "old" or "new", or use those as aliases for other relations, is not changed. For an INSERT, old values will generally be NULL, and for a DELETE, new values will generally be NULL, but that may change for an INSERT with an ON CONFLICT ... DO UPDATE clause, or if a query rewrite rule changes the command type. Therefore, we put no restrictions on the use of old and new in any DML queries. Dean Rasheed, reviewed by Jian He and Jeff Davis. Discussion: https://postgr.es/m/CAEZATCWx0J0-v=Qjc6gXzR=KtsdvAE7Ow=D=mu50AgOe+pvisQ@mail.gmail.com
845 lines
34 KiB
Plaintext
845 lines
34 KiB
Plaintext
<!--
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doc/src/sgml/ref/insert.sgml
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PostgreSQL documentation
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-->
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<refentry id="sql-insert">
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<indexterm zone="sql-insert">
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<primary>INSERT</primary>
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</indexterm>
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<refmeta>
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<refentrytitle>INSERT</refentrytitle>
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<manvolnum>7</manvolnum>
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<refmiscinfo>SQL - Language Statements</refmiscinfo>
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</refmeta>
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<refnamediv>
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<refname>INSERT</refname>
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<refpurpose>create new rows in a table</refpurpose>
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</refnamediv>
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<refsynopsisdiv>
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<synopsis>
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[ WITH [ RECURSIVE ] <replaceable class="parameter">with_query</replaceable> [, ...] ]
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INSERT INTO <replaceable class="parameter">table_name</replaceable> [ AS <replaceable class="parameter">alias</replaceable> ] [ ( <replaceable class="parameter">column_name</replaceable> [, ...] ) ]
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[ OVERRIDING { SYSTEM | USER } VALUE ]
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{ DEFAULT VALUES | VALUES ( { <replaceable class="parameter">expression</replaceable> | DEFAULT } [, ...] ) [, ...] | <replaceable class="parameter">query</replaceable> }
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[ ON CONFLICT [ <replaceable class="parameter">conflict_target</replaceable> ] <replaceable class="parameter">conflict_action</replaceable> ]
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[ RETURNING [ WITH ( { OLD | NEW } AS <replaceable class="parameter">output_alias</replaceable> [, ...] ) ]
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{ * | <replaceable class="parameter">output_expression</replaceable> [ [ AS ] <replaceable class="parameter">output_name</replaceable> ] } [, ...] ]
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<phrase>where <replaceable class="parameter">conflict_target</replaceable> can be one of:</phrase>
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( { <replaceable class="parameter">index_column_name</replaceable> | ( <replaceable class="parameter">index_expression</replaceable> ) } [ COLLATE <replaceable class="parameter">collation</replaceable> ] [ <replaceable class="parameter">opclass</replaceable> ] [, ...] ) [ WHERE <replaceable class="parameter">index_predicate</replaceable> ]
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ON CONSTRAINT <replaceable class="parameter">constraint_name</replaceable>
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<phrase>and <replaceable class="parameter">conflict_action</replaceable> is one of:</phrase>
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DO NOTHING
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DO UPDATE SET { <replaceable class="parameter">column_name</replaceable> = { <replaceable class="parameter">expression</replaceable> | DEFAULT } |
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( <replaceable class="parameter">column_name</replaceable> [, ...] ) = [ ROW ] ( { <replaceable class="parameter">expression</replaceable> | DEFAULT } [, ...] ) |
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( <replaceable class="parameter">column_name</replaceable> [, ...] ) = ( <replaceable class="parameter">sub-SELECT</replaceable> )
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} [, ...]
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[ WHERE <replaceable class="parameter">condition</replaceable> ]
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</synopsis>
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</refsynopsisdiv>
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<refsect1>
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<title>Description</title>
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<para>
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<command>INSERT</command> inserts new rows into a table.
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One can insert one or more rows specified by value expressions,
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or zero or more rows resulting from a query.
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</para>
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<para>
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The target column names can be listed in any order. If no list of
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column names is given at all, the default is all the columns of the
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table in their declared order; or the first <replaceable>N</replaceable> column
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names, if there are only <replaceable>N</replaceable> columns supplied by the
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<literal>VALUES</literal> clause or <replaceable>query</replaceable>. The values
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supplied by the <literal>VALUES</literal> clause or <replaceable>query</replaceable> are
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associated with the explicit or implicit column list left-to-right.
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</para>
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<para>
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Each column not present in the explicit or implicit column list will be
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filled with a default value, either its declared default value
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or null if there is none.
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</para>
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<para>
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If the expression for any column is not of the correct data type,
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automatic type conversion will be attempted.
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</para>
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<para>
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<command>INSERT</command> into tables that lack unique indexes will
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not be blocked by concurrent activity. Tables with unique indexes
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might block if concurrent sessions perform actions that lock or modify
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rows matching the unique index values being inserted; the details
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are covered in <xref linkend="index-unique-checks"/>.
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<literal>ON CONFLICT</literal> can be used to specify an alternative
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action to raising a unique constraint or exclusion constraint
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violation error. (See <xref linkend="sql-on-conflict"/> below.)
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</para>
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<para>
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The optional <literal>RETURNING</literal> clause causes <command>INSERT</command>
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to compute and return value(s) based on each row actually inserted
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(or updated, if an <literal>ON CONFLICT DO UPDATE</literal> clause was
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used). This is primarily useful for obtaining values that were
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supplied by defaults, such as a serial sequence number. However,
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any expression using the table's columns is allowed. The syntax of
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the <literal>RETURNING</literal> list is identical to that of the output
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list of <command>SELECT</command>. Only rows that were successfully
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inserted or updated will be returned. For example, if a row was
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locked but not updated because an <literal>ON CONFLICT DO UPDATE
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... WHERE</literal> clause <replaceable
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class="parameter">condition</replaceable> was not satisfied, the
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row will not be returned.
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</para>
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<para>
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You must have <literal>INSERT</literal> privilege on a table in
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order to insert into it. If <literal>ON CONFLICT DO UPDATE</literal> is
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present, <literal>UPDATE</literal> privilege on the table is also
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required.
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</para>
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<para>
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If a column list is specified, you only need
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<literal>INSERT</literal> privilege on the listed columns.
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Similarly, when <literal>ON CONFLICT DO UPDATE</literal> is specified, you
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only need <literal>UPDATE</literal> privilege on the column(s) that are
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listed to be updated. However, <literal>ON CONFLICT DO UPDATE</literal>
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also requires <literal>SELECT</literal> privilege on any column whose
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values are read in the <literal>ON CONFLICT DO UPDATE</literal>
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expressions or <replaceable>condition</replaceable>.
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</para>
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<para>
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Use of the <literal>RETURNING</literal> clause requires <literal>SELECT</literal>
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privilege on all columns mentioned in <literal>RETURNING</literal>.
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If you use the <replaceable
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class="parameter">query</replaceable> clause to insert rows from a
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query, you of course need to have <literal>SELECT</literal> privilege on
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any table or column used in the query.
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</para>
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</refsect1>
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<refsect1>
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<title>Parameters</title>
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<refsect2>
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<title>Inserting</title>
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<para>
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This section covers parameters that may be used when only
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inserting new rows. Parameters <emphasis>exclusively</emphasis>
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used with the <literal>ON CONFLICT</literal> clause are described
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separately.
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</para>
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<variablelist>
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<varlistentry>
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<term><replaceable class="parameter">with_query</replaceable></term>
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<listitem>
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<para>
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The <literal>WITH</literal> clause allows you to specify one or more
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subqueries that can be referenced by name in the <command>INSERT</command>
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query. See <xref linkend="queries-with"/> and <xref linkend="sql-select"/>
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for details.
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</para>
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<para>
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It is possible for the <replaceable class="parameter">query</replaceable>
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(<command>SELECT</command> statement)
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to also contain a <literal>WITH</literal> clause. In such a case both
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sets of <replaceable>with_query</replaceable> can be referenced within
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the <replaceable class="parameter">query</replaceable>, but the
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second one takes precedence since it is more closely nested.
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</para>
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</listitem>
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</varlistentry>
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<varlistentry>
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<term><replaceable class="parameter">table_name</replaceable></term>
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<listitem>
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<para>
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The name (optionally schema-qualified) of an existing table.
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</para>
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</listitem>
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</varlistentry>
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<varlistentry>
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<term><replaceable class="parameter">alias</replaceable></term>
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<listitem>
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<para>
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A substitute name for <replaceable
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class="parameter">table_name</replaceable>. When an alias is
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provided, it completely hides the actual name of the table.
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This is particularly useful when <literal>ON CONFLICT DO UPDATE</literal>
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targets a table named <varname>excluded</varname>, since that will otherwise
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be taken as the name of the special table representing the row proposed
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for insertion.
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</para>
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</listitem>
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</varlistentry>
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<varlistentry>
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<term><replaceable class="parameter">column_name</replaceable></term>
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<listitem>
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<para>
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The name of a column in the table named by <replaceable
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class="parameter">table_name</replaceable>. The column name
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can be qualified with a subfield name or array subscript, if
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needed. (Inserting into only some fields of a composite
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column leaves the other fields null.) When referencing a
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column with <literal>ON CONFLICT DO UPDATE</literal>, do not include
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the table's name in the specification of a target column. For
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example, <literal>INSERT INTO table_name ... ON CONFLICT DO UPDATE
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SET table_name.col = 1</literal> is invalid (this follows the general
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behavior for <command>UPDATE</command>).
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</para>
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</listitem>
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</varlistentry>
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<varlistentry>
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<term><literal>OVERRIDING SYSTEM VALUE</literal></term>
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<listitem>
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<para>
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If this clause is specified, then any values supplied for identity
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columns will override the default sequence-generated values.
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</para>
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<para>
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For an identity column defined as <literal>GENERATED ALWAYS</literal>,
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it is an error to insert an explicit value (other than
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<literal>DEFAULT</literal>) without specifying either
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<literal>OVERRIDING SYSTEM VALUE</literal> or <literal>OVERRIDING USER
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VALUE</literal>. (For an identity column defined as
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<literal>GENERATED BY DEFAULT</literal>, <literal>OVERRIDING SYSTEM
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VALUE</literal> is the normal behavior and specifying it does nothing,
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but <productname>PostgreSQL</productname> allows it as an extension.)
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</para>
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</listitem>
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</varlistentry>
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<varlistentry>
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<term><literal>OVERRIDING USER VALUE</literal></term>
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<listitem>
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<para>
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If this clause is specified, then any values supplied for identity
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columns are ignored and the default sequence-generated values are
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applied.
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</para>
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<para>
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This clause is useful for example when copying values between tables.
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Writing <literal>INSERT INTO tbl2 OVERRIDING USER VALUE SELECT * FROM
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tbl1</literal> will copy from <literal>tbl1</literal> all columns that
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are not identity columns in <literal>tbl2</literal> while values for
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the identity columns in <literal>tbl2</literal> will be generated by
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the sequences associated with <literal>tbl2</literal>.
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</para>
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</listitem>
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</varlistentry>
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<varlistentry>
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<term><literal>DEFAULT VALUES</literal></term>
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<listitem>
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<para>
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All columns will be filled with their default values, as if
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<literal>DEFAULT</literal> were explicitly specified for each column.
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(An <literal>OVERRIDING</literal> clause is not permitted in this
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form.)
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</para>
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</listitem>
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</varlistentry>
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<varlistentry>
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<term><replaceable class="parameter">expression</replaceable></term>
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<listitem>
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<para>
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An expression or value to assign to the corresponding column.
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</para>
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</listitem>
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</varlistentry>
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<varlistentry>
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<term><literal>DEFAULT</literal></term>
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<listitem>
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<para>
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The corresponding column will be filled with its default value. An
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identity column will be filled with a new value generated by the
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associated sequence. For a generated column, specifying this is
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permitted but merely specifies the normal behavior of computing the
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column from its generation expression.
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</para>
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</listitem>
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</varlistentry>
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<varlistentry>
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<term><replaceable class="parameter">query</replaceable></term>
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<listitem>
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<para>
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A query (<command>SELECT</command> statement) that supplies the
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rows to be inserted. Refer to the
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<xref linkend="sql-select"/>
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statement for a description of the syntax.
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</para>
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</listitem>
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</varlistentry>
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<varlistentry>
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<term><replaceable class="parameter">output_alias</replaceable></term>
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<listitem>
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<para>
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An optional substitute name for <literal>OLD</literal> or
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<literal>NEW</literal> rows in the <literal>RETURNING</literal> list.
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</para>
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<para>
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By default, old values from the target table can be returned by writing
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<literal>OLD.<replaceable class="parameter">column_name</replaceable></literal>
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or <literal>OLD.*</literal>, and new values can be returned by writing
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<literal>NEW.<replaceable class="parameter">column_name</replaceable></literal>
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or <literal>NEW.*</literal>. When an alias is provided, these names are
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hidden and the old or new rows must be referred to using the alias.
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For example <literal>RETURNING WITH (OLD AS o, NEW AS n) o.*, n.*</literal>.
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</para>
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</listitem>
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</varlistentry>
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<varlistentry>
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<term><replaceable class="parameter">output_expression</replaceable></term>
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<listitem>
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<para>
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An expression to be computed and returned by the
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<command>INSERT</command> command after each row is inserted or
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updated. The expression can use any column names of the table
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named by <replaceable
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class="parameter">table_name</replaceable>. Write
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<literal>*</literal> to return all columns of the inserted or updated
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row(s).
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</para>
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<para>
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A column name or <literal>*</literal> may be qualified using
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<literal>OLD</literal> or <literal>NEW</literal>, or the corresponding
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<replaceable class="parameter">output_alias</replaceable> for
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<literal>OLD</literal> or <literal>NEW</literal>, to cause old or new
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values to be returned. An unqualified column name, or
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<literal>*</literal>, or a column name or <literal>*</literal>
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qualified using the target table name or alias will return new values.
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</para>
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<para>
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For a simple <command>INSERT</command>, all old values will be
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<literal>NULL</literal>. However, for an <command>INSERT</command>
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with an <literal>ON CONFLICT DO UPDATE</literal> clause, the old
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values may be non-<literal>NULL</literal>.
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</para>
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</listitem>
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</varlistentry>
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<varlistentry>
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<term><replaceable class="parameter">output_name</replaceable></term>
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<listitem>
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<para>
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A name to use for a returned column.
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</para>
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</listitem>
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</varlistentry>
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</variablelist>
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</refsect2>
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<refsect2 id="sql-on-conflict" xreflabel="ON CONFLICT Clause">
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<title><literal>ON CONFLICT</literal> Clause</title>
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<indexterm zone="sql-insert">
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<primary>UPSERT</primary>
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</indexterm>
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<indexterm zone="sql-insert">
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<primary>ON CONFLICT</primary>
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</indexterm>
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<para>
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The optional <literal>ON CONFLICT</literal> clause specifies an
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alternative action to raising a unique violation or exclusion
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constraint violation error. For each individual row proposed for
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insertion, either the insertion proceeds, or, if an
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<emphasis>arbiter</emphasis> constraint or index specified by
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<parameter>conflict_target</parameter> is violated, the
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alternative <parameter>conflict_action</parameter> is taken.
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<literal>ON CONFLICT DO NOTHING</literal> simply avoids inserting
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a row as its alternative action. <literal>ON CONFLICT DO
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UPDATE</literal> updates the existing row that conflicts with the
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row proposed for insertion as its alternative action.
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</para>
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<para>
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<parameter>conflict_target</parameter> can perform
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<emphasis>unique index inference</emphasis>. When performing
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inference, it consists of one or more <replaceable
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class="parameter">index_column_name</replaceable> columns and/or
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<replaceable class="parameter">index_expression</replaceable>
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expressions, and an optional <replaceable class="parameter">index_predicate</replaceable>. All <replaceable
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class="parameter">table_name</replaceable> unique indexes that,
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without regard to order, contain exactly the
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<parameter>conflict_target</parameter>-specified
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columns/expressions are inferred (chosen) as arbiter indexes. If
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an <replaceable class="parameter">index_predicate</replaceable> is
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specified, it must, as a further requirement for inference,
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satisfy arbiter indexes. Note that this means a non-partial
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unique index (a unique index without a predicate) will be inferred
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(and thus used by <literal>ON CONFLICT</literal>) if such an index
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satisfying every other criteria is available. If an attempt at
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inference is unsuccessful, an error is raised.
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</para>
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<para>
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<literal>ON CONFLICT DO UPDATE</literal> guarantees an atomic
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<command>INSERT</command> or <command>UPDATE</command> outcome;
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provided there is no independent error, one of those two outcomes
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is guaranteed, even under high concurrency. This is also known as
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<firstterm>UPSERT</firstterm> — <quote>UPDATE or
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INSERT</quote>.
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</para>
|
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|
|
<variablelist>
|
|
<varlistentry>
|
|
<term><replaceable class="parameter">conflict_target</replaceable></term>
|
|
<listitem>
|
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<para>
|
|
Specifies which conflicts <literal>ON CONFLICT</literal> takes
|
|
the alternative action on by choosing <firstterm>arbiter
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indexes</firstterm>. Either performs <emphasis>unique index
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|
inference</emphasis>, or names a constraint explicitly. For
|
|
<literal>ON CONFLICT DO NOTHING</literal>, it is optional to
|
|
specify a <parameter>conflict_target</parameter>; when
|
|
omitted, conflicts with all usable constraints (and unique
|
|
indexes) are handled. For <literal>ON CONFLICT DO
|
|
UPDATE</literal>, a <parameter>conflict_target</parameter>
|
|
<emphasis>must</emphasis> be provided.
|
|
</para>
|
|
</listitem>
|
|
</varlistentry>
|
|
|
|
<varlistentry>
|
|
<term><replaceable class="parameter">conflict_action</replaceable></term>
|
|
<listitem>
|
|
<para>
|
|
<parameter>conflict_action</parameter> specifies an
|
|
alternative <literal>ON CONFLICT</literal> action. It can be
|
|
either <literal>DO NOTHING</literal>, or a <literal>DO
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|
UPDATE</literal> clause specifying the exact details of the
|
|
<literal>UPDATE</literal> action to be performed in case of a
|
|
conflict. The <literal>SET</literal> and
|
|
<literal>WHERE</literal> clauses in <literal>ON CONFLICT DO
|
|
UPDATE</literal> have access to the existing row using the
|
|
table's name (or an alias), and to the row proposed for insertion
|
|
using the special <varname>excluded</varname> table.
|
|
<literal>SELECT</literal> privilege is required on any column in the
|
|
target table where corresponding <varname>excluded</varname>
|
|
columns are read.
|
|
</para>
|
|
<para>
|
|
Note that the effects of all per-row <literal>BEFORE
|
|
INSERT</literal> triggers are reflected in
|
|
<varname>excluded</varname> values, since those effects may
|
|
have contributed to the row being excluded from insertion.
|
|
</para>
|
|
</listitem>
|
|
</varlistentry>
|
|
|
|
<varlistentry>
|
|
<term><replaceable class="parameter">index_column_name</replaceable></term>
|
|
<listitem>
|
|
<para>
|
|
The name of a <replaceable
|
|
class="parameter">table_name</replaceable> column. Used to
|
|
infer arbiter indexes. Follows <command>CREATE
|
|
INDEX</command> format. <literal>SELECT</literal> privilege on
|
|
<replaceable class="parameter">index_column_name</replaceable>
|
|
is required.
|
|
</para>
|
|
</listitem>
|
|
</varlistentry>
|
|
|
|
<varlistentry>
|
|
<term><replaceable class="parameter">index_expression</replaceable></term>
|
|
<listitem>
|
|
<para>
|
|
Similar to <replaceable
|
|
class="parameter">index_column_name</replaceable>, but used to
|
|
infer expressions on <replaceable
|
|
class="parameter">table_name</replaceable> columns appearing
|
|
within index definitions (not simple columns). Follows
|
|
<command>CREATE INDEX</command> format. <literal>SELECT</literal>
|
|
privilege on any column appearing within <replaceable
|
|
class="parameter">index_expression</replaceable> is required.
|
|
</para>
|
|
</listitem>
|
|
</varlistentry>
|
|
|
|
<varlistentry>
|
|
<term><replaceable class="parameter">collation</replaceable></term>
|
|
<listitem>
|
|
<para>
|
|
When specified, mandates that corresponding <replaceable
|
|
class="parameter">index_column_name</replaceable> or
|
|
<replaceable class="parameter">index_expression</replaceable>
|
|
use a particular collation in order to be matched during
|
|
inference. Typically this is omitted, as collations usually
|
|
do not affect whether or not a constraint violation occurs.
|
|
Follows <command>CREATE INDEX</command> format.
|
|
</para>
|
|
</listitem>
|
|
</varlistentry>
|
|
|
|
<varlistentry>
|
|
<term><replaceable class="parameter">opclass</replaceable></term>
|
|
<listitem>
|
|
<para>
|
|
When specified, mandates that corresponding <replaceable
|
|
class="parameter">index_column_name</replaceable> or
|
|
<replaceable class="parameter">index_expression</replaceable>
|
|
use particular operator class in order to be matched during
|
|
inference. Typically this is omitted, as the
|
|
<emphasis>equality</emphasis> semantics are often equivalent
|
|
across a type's operator classes anyway, or because it's
|
|
sufficient to trust that the defined unique indexes have the
|
|
pertinent definition of equality. Follows <command>CREATE
|
|
INDEX</command> format.
|
|
</para>
|
|
</listitem>
|
|
</varlistentry>
|
|
|
|
<varlistentry>
|
|
<term><replaceable class="parameter">index_predicate</replaceable></term>
|
|
<listitem>
|
|
<para>
|
|
Used to allow inference of partial unique indexes. Any
|
|
indexes that satisfy the predicate (which need not actually be
|
|
partial indexes) can be inferred. Follows <command>CREATE
|
|
INDEX</command> format. <literal>SELECT</literal> privilege on any
|
|
column appearing within <replaceable
|
|
class="parameter">index_predicate</replaceable> is required.
|
|
</para>
|
|
</listitem>
|
|
</varlistentry>
|
|
|
|
<varlistentry>
|
|
<term><replaceable class="parameter">constraint_name</replaceable></term>
|
|
<listitem>
|
|
<para>
|
|
Explicitly specifies an arbiter
|
|
<emphasis>constraint</emphasis> by name, rather than inferring
|
|
a constraint or index.
|
|
</para>
|
|
</listitem>
|
|
</varlistentry>
|
|
|
|
<varlistentry>
|
|
<term><replaceable class="parameter">condition</replaceable></term>
|
|
<listitem>
|
|
<para>
|
|
An expression that returns a value of type
|
|
<type>boolean</type>. Only rows for which this expression
|
|
returns <literal>true</literal> will be updated, although all
|
|
rows will be locked when the <literal>ON CONFLICT DO UPDATE</literal>
|
|
action is taken. Note that
|
|
<replaceable>condition</replaceable> is evaluated last, after
|
|
a conflict has been identified as a candidate to update.
|
|
</para>
|
|
</listitem>
|
|
</varlistentry>
|
|
</variablelist>
|
|
<para>
|
|
Note that exclusion constraints are not supported as arbiters with
|
|
<literal>ON CONFLICT DO UPDATE</literal>. In all cases, only
|
|
<literal>NOT DEFERRABLE</literal> constraints and unique indexes
|
|
are supported as arbiters.
|
|
</para>
|
|
|
|
<para>
|
|
<command>INSERT</command> with an <literal>ON CONFLICT DO UPDATE</literal>
|
|
clause is a <quote>deterministic</quote> statement. This means
|
|
that the command will not be allowed to affect any single existing
|
|
row more than once; a cardinality violation error will be raised
|
|
when this situation arises. Rows proposed for insertion should
|
|
not duplicate each other in terms of attributes constrained by an
|
|
arbiter index or constraint.
|
|
</para>
|
|
|
|
<para>
|
|
Note that it is currently not supported for the
|
|
<literal>ON CONFLICT DO UPDATE</literal> clause of an
|
|
<command>INSERT</command> applied to a partitioned table to update the
|
|
partition key of a conflicting row such that it requires the row be moved
|
|
to a new partition.
|
|
</para>
|
|
<tip>
|
|
<para>
|
|
It is often preferable to use unique index inference rather than
|
|
naming a constraint directly using <literal>ON CONFLICT ON
|
|
CONSTRAINT</literal> <replaceable class="parameter">
|
|
constraint_name</replaceable>. Inference will continue to work
|
|
correctly when the underlying index is replaced by another more
|
|
or less equivalent index in an overlapping way, for example when
|
|
using <literal>CREATE UNIQUE INDEX ... CONCURRENTLY</literal>
|
|
before dropping the index being replaced.
|
|
</para>
|
|
</tip>
|
|
|
|
</refsect2>
|
|
</refsect1>
|
|
|
|
<refsect1>
|
|
<title>Outputs</title>
|
|
|
|
<para>
|
|
On successful completion, an <command>INSERT</command> command returns a command
|
|
tag of the form
|
|
<screen>
|
|
INSERT <replaceable>oid</replaceable> <replaceable class="parameter">count</replaceable>
|
|
</screen>
|
|
The <replaceable class="parameter">count</replaceable> is the number of
|
|
rows inserted or updated. <replaceable>oid</replaceable> is always 0 (it
|
|
used to be the <acronym>OID</acronym> assigned to the inserted row if
|
|
<replaceable>count</replaceable> was exactly one and the target table was
|
|
declared <literal>WITH OIDS</literal> and 0 otherwise, but creating a table
|
|
<literal>WITH OIDS</literal> is not supported anymore).
|
|
</para>
|
|
|
|
<para>
|
|
If the <command>INSERT</command> command contains a <literal>RETURNING</literal>
|
|
clause, the result will be similar to that of a <command>SELECT</command>
|
|
statement containing the columns and values defined in the
|
|
<literal>RETURNING</literal> list, computed over the row(s) inserted or
|
|
updated by the command.
|
|
</para>
|
|
</refsect1>
|
|
|
|
<refsect1>
|
|
<title>Notes</title>
|
|
|
|
<para>
|
|
If the specified table is a partitioned table, each row is routed to
|
|
the appropriate partition and inserted into it. If the specified table
|
|
is a partition, an error will occur if one of the input rows violates
|
|
the partition constraint.
|
|
</para>
|
|
|
|
<para>
|
|
You may also wish to consider using <command>MERGE</command>, since that
|
|
allows mixing <command>INSERT</command>, <command>UPDATE</command>, and
|
|
<command>DELETE</command> within a single statement.
|
|
See <xref linkend="sql-merge"/>.
|
|
</para>
|
|
</refsect1>
|
|
|
|
<refsect1>
|
|
<title>Examples</title>
|
|
|
|
<para>
|
|
Insert a single row into table <literal>films</literal>:
|
|
|
|
<programlisting>
|
|
INSERT INTO films VALUES
|
|
('UA502', 'Bananas', 105, '1971-07-13', 'Comedy', '82 minutes');
|
|
</programlisting>
|
|
</para>
|
|
|
|
<para>
|
|
In this example, the <literal>len</literal> column is
|
|
omitted and therefore it will have the default value:
|
|
|
|
<programlisting>
|
|
INSERT INTO films (code, title, did, date_prod, kind)
|
|
VALUES ('T_601', 'Yojimbo', 106, '1961-06-16', 'Drama');
|
|
</programlisting>
|
|
</para>
|
|
|
|
<para>
|
|
This example uses the <literal>DEFAULT</literal> clause for
|
|
the date columns rather than specifying a value:
|
|
|
|
<programlisting>
|
|
INSERT INTO films VALUES
|
|
('UA502', 'Bananas', 105, DEFAULT, 'Comedy', '82 minutes');
|
|
INSERT INTO films (code, title, did, date_prod, kind)
|
|
VALUES ('T_601', 'Yojimbo', 106, DEFAULT, 'Drama');
|
|
</programlisting>
|
|
</para>
|
|
|
|
<para>
|
|
To insert a row consisting entirely of default values:
|
|
|
|
<programlisting>
|
|
INSERT INTO films DEFAULT VALUES;
|
|
</programlisting>
|
|
</para>
|
|
|
|
<para>
|
|
To insert multiple rows using the multirow <command>VALUES</command> syntax:
|
|
|
|
<programlisting>
|
|
INSERT INTO films (code, title, did, date_prod, kind) VALUES
|
|
('B6717', 'Tampopo', 110, '1985-02-10', 'Comedy'),
|
|
('HG120', 'The Dinner Game', 140, DEFAULT, 'Comedy');
|
|
</programlisting>
|
|
</para>
|
|
|
|
<para>
|
|
This example inserts some rows into table
|
|
<literal>films</literal> from a table <literal>tmp_films</literal>
|
|
with the same column layout as <literal>films</literal>:
|
|
|
|
<programlisting>
|
|
INSERT INTO films SELECT * FROM tmp_films WHERE date_prod < '2004-05-07';
|
|
</programlisting>
|
|
</para>
|
|
|
|
<para>
|
|
This example inserts into array columns:
|
|
|
|
<programlisting>
|
|
-- Create an empty 3x3 gameboard for noughts-and-crosses
|
|
INSERT INTO tictactoe (game, board[1:3][1:3])
|
|
VALUES (1, '{{" "," "," "},{" "," "," "},{" "," "," "}}');
|
|
-- The subscripts in the above example aren't really needed
|
|
INSERT INTO tictactoe (game, board)
|
|
VALUES (2, '{{X," "," "},{" ",O," "},{" ",X," "}}');
|
|
</programlisting>
|
|
</para>
|
|
|
|
<para>
|
|
Insert a single row into table <literal>distributors</literal>, returning
|
|
the sequence number generated by the <literal>DEFAULT</literal> clause:
|
|
|
|
<programlisting>
|
|
INSERT INTO distributors (did, dname) VALUES (DEFAULT, 'XYZ Widgets')
|
|
RETURNING did;
|
|
</programlisting>
|
|
</para>
|
|
|
|
<para>
|
|
Increment the sales count of the salesperson who manages the
|
|
account for Acme Corporation, and record the whole updated row
|
|
along with current time in a log table:
|
|
<programlisting>
|
|
WITH upd AS (
|
|
UPDATE employees SET sales_count = sales_count + 1 WHERE id =
|
|
(SELECT sales_person FROM accounts WHERE name = 'Acme Corporation')
|
|
RETURNING *
|
|
)
|
|
INSERT INTO employees_log SELECT *, current_timestamp FROM upd;
|
|
</programlisting>
|
|
</para>
|
|
<para>
|
|
Insert or update new distributors as appropriate. Assumes a unique
|
|
index has been defined that constrains values appearing in the
|
|
<literal>did</literal> column. Note that the special
|
|
<varname>excluded</varname> table is used to reference values originally
|
|
proposed for insertion:
|
|
<programlisting>
|
|
INSERT INTO distributors (did, dname)
|
|
VALUES (5, 'Gizmo Transglobal'), (6, 'Associated Computing, Inc')
|
|
ON CONFLICT (did) DO UPDATE SET dname = EXCLUDED.dname;
|
|
</programlisting>
|
|
</para>
|
|
<para>
|
|
Insert or update new distributors as above, returning information
|
|
about any existing values that were updated, together with the new data
|
|
inserted. Note that the returned values for <literal>old_did</literal>
|
|
and <literal>old_dname</literal> will be <literal>NULL</literal> for
|
|
non-conflicting rows:
|
|
<programlisting>
|
|
INSERT INTO distributors (did, dname)
|
|
VALUES (5, 'Gizmo Transglobal'), (6, 'Associated Computing, Inc')
|
|
ON CONFLICT (did) DO UPDATE SET dname = EXCLUDED.dname
|
|
RETURNING old.did AS old_did, old.dname AS old_dname,
|
|
new.did AS new_did, new.dname AS new_dname;
|
|
</programlisting>
|
|
</para>
|
|
<para>
|
|
Insert a distributor, or do nothing for rows proposed for insertion
|
|
when an existing, excluded row (a row with a matching constrained
|
|
column or columns after before row insert triggers fire) exists.
|
|
Example assumes a unique index has been defined that constrains
|
|
values appearing in the <literal>did</literal> column:
|
|
<programlisting>
|
|
INSERT INTO distributors (did, dname) VALUES (7, 'Redline GmbH')
|
|
ON CONFLICT (did) DO NOTHING;
|
|
</programlisting>
|
|
</para>
|
|
<para>
|
|
Insert or update new distributors as appropriate. Example assumes
|
|
a unique index has been defined that constrains values appearing in
|
|
the <literal>did</literal> column. <literal>WHERE</literal> clause is
|
|
used to limit the rows actually updated (any existing row not
|
|
updated will still be locked, though):
|
|
<programlisting>
|
|
-- Don't update existing distributors based in a certain ZIP code
|
|
INSERT INTO distributors AS d (did, dname) VALUES (8, 'Anvil Distribution')
|
|
ON CONFLICT (did) DO UPDATE
|
|
SET dname = EXCLUDED.dname || ' (formerly ' || d.dname || ')'
|
|
WHERE d.zipcode <> '21201';
|
|
|
|
-- Name a constraint directly in the statement (uses associated
|
|
-- index to arbitrate taking the DO NOTHING action)
|
|
INSERT INTO distributors (did, dname) VALUES (9, 'Antwerp Design')
|
|
ON CONFLICT ON CONSTRAINT distributors_pkey DO NOTHING;
|
|
</programlisting>
|
|
</para>
|
|
<para>
|
|
Insert new distributor if possible; otherwise
|
|
<literal>DO NOTHING</literal>. Example assumes a unique index has been
|
|
defined that constrains values appearing in the
|
|
<literal>did</literal> column on a subset of rows where the
|
|
<literal>is_active</literal> Boolean column evaluates to
|
|
<literal>true</literal>:
|
|
<programlisting>
|
|
-- This statement could infer a partial unique index on "did"
|
|
-- with a predicate of "WHERE is_active", but it could also
|
|
-- just use a regular unique constraint on "did"
|
|
INSERT INTO distributors (did, dname) VALUES (10, 'Conrad International')
|
|
ON CONFLICT (did) WHERE is_active DO NOTHING;
|
|
</programlisting></para>
|
|
</refsect1>
|
|
|
|
<refsect1>
|
|
<title>Compatibility</title>
|
|
|
|
<para>
|
|
<command>INSERT</command> conforms to the SQL standard, except that
|
|
the <literal>RETURNING</literal> clause is a
|
|
<productname>PostgreSQL</productname> extension, as is the ability
|
|
to use <literal>WITH</literal> with <command>INSERT</command>, and the ability to
|
|
specify an alternative action with <literal>ON CONFLICT</literal>.
|
|
Also, the case in
|
|
which a column name list is omitted, but not all the columns are
|
|
filled from the <literal>VALUES</literal> clause or <replaceable>query</replaceable>,
|
|
is disallowed by the standard. If you prefer a more SQL standard
|
|
conforming statement than <literal>ON CONFLICT</literal>, see
|
|
<xref linkend="sql-merge"/>.
|
|
</para>
|
|
|
|
<para>
|
|
The SQL standard specifies that <literal>OVERRIDING SYSTEM VALUE</literal>
|
|
can only be specified if an identity column that is generated always
|
|
exists. PostgreSQL allows the clause in any case and ignores it if it is
|
|
not applicable.
|
|
</para>
|
|
|
|
<para>
|
|
Possible limitations of the <replaceable
|
|
class="parameter">query</replaceable> clause are documented under
|
|
<xref linkend="sql-select"/>.
|
|
</para>
|
|
</refsect1>
|
|
</refentry>
|