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https://github.com/postgres/postgres.git
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Updates create_function.sgml with fixes for new foreign keys
This commit is contained in:
Bruce Momjian
@ -1,5 +1,5 @@
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<!--
|
||||
$Header: /cvsroot/pgsql/doc/src/sgml/ref/create_table.sgml,v 1.22 2000/04/13 07:19:27 momjian Exp $
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||||
$Header: /cvsroot/pgsql/doc/src/sgml/ref/create_table.sgml,v 1.23 2000/04/14 21:44:21 momjian Exp $
|
||||
Postgres documentation
|
||||
-->
|
||||
|
||||
@ -97,15 +97,16 @@ CREATE [ TEMPORARY | TEMP ] TABLE <replaceable class="PARAMETER">table</replacea
|
||||
<term><replaceable>column_constraint_clause</replaceable></term>
|
||||
<listitem>
|
||||
<para>
|
||||
The optional column constraint clauses specify a list of integrity
|
||||
constraints or tests which new or updated entries must satisfy for
|
||||
an insert or update operation to succeed. Each constraint
|
||||
must evaluate to a boolean expression. Although <acronym>SQL92</acronym>
|
||||
requires the <replaceable class="PARAMETER">column_constraint_clause</replaceable>
|
||||
to refer to that column only, <productname>Postgres</productname>
|
||||
allows multiple columns
|
||||
to be referenced within a single column constraint.
|
||||
See the column constraint clause for more information.
|
||||
The optional column constraint clauses specify a list of
|
||||
integrity constraints or tests which new or updated entries must
|
||||
satisfy for an insert or update operation to succeed. Each
|
||||
constraint must evaluate to a boolean expression. Although
|
||||
<acronym>SQL92</acronym> requires the <replaceable
|
||||
class="PARAMETER">column_constraint_clause</replaceable> to
|
||||
refer to that column only, <productname>Postgres</productname>
|
||||
allows multiple columns to be referenced within a single column
|
||||
constraint. See the column constraint clause for more
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||||
information.
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||||
</para>
|
||||
</listitem>
|
||||
</varlistentry>
|
||||
@ -114,16 +115,16 @@ CREATE [ TEMPORARY | TEMP ] TABLE <replaceable class="PARAMETER">table</replacea
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||||
<term><replaceable>table_constraint_clause</replaceable></term>
|
||||
<listitem>
|
||||
<para>
|
||||
The optional table CONSTRAINT clause specifies a list of integrity
|
||||
constraints which new or updated entries must satisfy for
|
||||
an insert or update operation to succeed. Each constraint
|
||||
must evaluate to a boolean expression. Multiple columns
|
||||
may be referenced within a single constraint.
|
||||
Only one PRIMARY KEY clause may be specified for a table;
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PRIMARY KEY <replaceable>column</replaceable>
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(a table constraint) and PRIMARY KEY (a column constraint) are
|
||||
mutually exclusive..
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See the table constraint clause for more information.
|
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The optional table CONSTRAINT clause specifies a
|
||||
list of integrity constraints which new or updated entries must
|
||||
satisfy for an insert or update operation to succeed. Each
|
||||
constraint must evaluate to a boolean expression. Multiple
|
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columns may be referenced within a single constraint. Only one
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PRIMARY KEY clause may be specified for a table;
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PRIMARY KEY <replaceable>column</replaceable> (a table
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constraint) and PRIMARY KEY (a column constraint)
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are mutually exclusive.. See the table constraint clause for
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more information.
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</para>
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</listitem>
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</varlistentry>
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@ -140,13 +141,6 @@ CREATE [ TEMPORARY | TEMP ] TABLE <replaceable class="PARAMETER">table</replacea
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<productname>Postgres</productname> automatically allows the created
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||||
table to inherit functions on tables above it in the inheritance
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hierarchy.
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<note>
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<title>Aside</title>
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||||
<para>
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||||
Inheritance of functions is done according
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||||
to the conventions of the Common Lisp Object System (CLOS).
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</para>
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</note>
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||||
</para>
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||||
</listitem>
|
||||
</varlistentry>
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||||
@ -227,7 +221,7 @@ ERROR: DEFAULT: type mismatched
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<para>
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<note>
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<para>
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As of Postgres version 6.0, consistant array dimensions within an
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As of Postgres version 6.0, consistent array dimensions within an
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||||
attribute are not enforced. This will likely change in a future
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||||
release.
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||||
</para>
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||||
@ -353,13 +347,13 @@ DEFAULT <replaceable class="PARAMETER">value</replaceable>
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||||
<varlistentry>
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||||
<term>SESSION_USER</term>
|
||||
<listitem>
|
||||
<simpara>not yet supported</simpara>
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||||
<simpara>See CURRENT_USER function</simpara>
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||||
</listitem>
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||||
</varlistentry>
|
||||
<varlistentry>
|
||||
<term>SYSTEM_USER</term>
|
||||
<listitem>
|
||||
<simpara>not yet supported</simpara>
|
||||
<simpara>See CURRENT_USER function</simpara>
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||||
</listitem>
|
||||
</varlistentry>
|
||||
</variablelist>
|
||||
@ -502,9 +496,9 @@ CREATE TABLE distributors (
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<listitem>
|
||||
<para>
|
||||
This column is a primary key, which implies that uniqueness is
|
||||
enforced by the system and that other tables may rely on this column
|
||||
as a unique identifier for rows.
|
||||
See PRIMARY KEY for more information.
|
||||
enforced by the system and that other tables may rely on this
|
||||
column as a unique identifier for rows. See PRIMARY KEY for more
|
||||
information.
|
||||
</para>
|
||||
</listitem>
|
||||
</varlistentry>
|
||||
@ -529,13 +523,12 @@ CREATE TABLE distributors (
|
||||
</title>
|
||||
|
||||
<para>
|
||||
The optional constraint
|
||||
clauses specify constraints or tests which new or updated entries
|
||||
must satisfy for an insert or update operation to succeed. Each constraint
|
||||
must evaluate to a boolean expression. Multiple attributes may be referenced within
|
||||
a single constraint. The use of PRIMARY KEY
|
||||
as a table constraint
|
||||
is mutually incompatible with PRIMARY KEY as a column constraint.
|
||||
The optional constraint clauses specify constraints or tests which
|
||||
new or updated entries must satisfy for an insert or update
|
||||
operation to succeed. Each constraint must evaluate to a boolean
|
||||
expression. Multiple attributes may be referenced within a single
|
||||
constraint. The use of PRIMARY KEY as a table constraint is mutually
|
||||
incompatible with PRIMARY KEY as a column constraint.
|
||||
</para>
|
||||
|
||||
<para>
|
||||
@ -550,10 +543,9 @@ CREATE TABLE distributors (
|
||||
</para>
|
||||
|
||||
<para>
|
||||
A column constraint is an integrity constraint defined as part
|
||||
of a column definition, and logically becomes a table
|
||||
constraint as soon as it is created. The column
|
||||
constraints available are:
|
||||
A column constraint is an integrity constraint defined as part of a
|
||||
column definition, and logically becomes a table constraint as soon
|
||||
as it is created. The column constraints available are:
|
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|
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<simplelist columns="1">
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<member>PRIMARY KEY</member>
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@ -563,14 +555,6 @@ CREATE TABLE distributors (
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<member>NOT NULL</member>
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||||
</simplelist>
|
||||
</para>
|
||||
|
||||
<note>
|
||||
<para>
|
||||
<productname>Postgres</productname> now
|
||||
(new for v7.0) supports
|
||||
REFERENCES integrity constraints.
|
||||
</para>
|
||||
</note>
|
||||
</refsect2>
|
||||
|
||||
<refsect2 id="R2-SQL-NOTNULL-1">
|
||||
@ -710,11 +694,11 @@ ERROR: Cannot insert a duplicate key into a unique index.
|
||||
<para>
|
||||
The column definitions of the specified columns do not have to
|
||||
include a NOT NULL constraint to be included in a UNIQUE
|
||||
constraint. Having more than one null value in a column without a
|
||||
NOT NULL constraint, does not violate a UNIQUE constraint.
|
||||
(This deviates from the <acronym>SQL92</acronym> definition, but
|
||||
is a more sensible convention. See the section on compatibility
|
||||
for more details.).
|
||||
constraint. Having more than one null value in a column without a
|
||||
NOT NULL constraint, does not violate a UNIQUE constraint. (This
|
||||
deviates from the <acronym>SQL92</acronym> definition, but is a
|
||||
more sensible convention. See the section on compatibility for more
|
||||
details.).
|
||||
</para>
|
||||
<para>
|
||||
Each UNIQUE column constraint must name a column that is
|
||||
@ -827,14 +811,13 @@ ERROR: ExecAppend: rejected due to CHECK constraint "<replaceable class="parame
|
||||
<title>Description</title>
|
||||
<para>
|
||||
The CHECK constraint specifies a restriction on allowed values
|
||||
within a column.
|
||||
The CHECK constraint is also allowed as a table constraint.
|
||||
within a column. The CHECK constraint is also allowed as a table
|
||||
constraint.
|
||||
</para>
|
||||
<para>
|
||||
The SQL92 CHECK column constraints can only be defined on, and
|
||||
refer to, one column of the table. <productname>Postgres</productname>
|
||||
does not have
|
||||
this restriction.
|
||||
refer to, one column of the table.
|
||||
<productname>Postgres</productname> does not have this restriction.
|
||||
</para>
|
||||
</refsect3>
|
||||
</refsect2>
|
||||
@ -883,11 +866,11 @@ ERROR: Cannot insert a duplicate key into a unique index.
|
||||
<refsect3>
|
||||
<title>Description</title>
|
||||
<para>
|
||||
The PRIMARY KEY column constraint specifies that a column of a table
|
||||
may contain only unique
|
||||
(non-duplicate), non-NULL values. The definition of
|
||||
the specified column does not have to include an explicit NOT NULL
|
||||
constraint to be included in a PRIMARY KEY constraint.
|
||||
The PRIMARY KEY column constraint specifies that a column of a
|
||||
table may contain only unique (non-duplicate), non-NULL values. The
|
||||
definition of the specified column does not have to include an
|
||||
explicit NOT NULL constraint to be included in a PRIMARY KEY
|
||||
constraint.
|
||||
</para>
|
||||
<para>
|
||||
Only one PRIMARY KEY can be specified for a table.
|
||||
@ -974,9 +957,11 @@ ERROR: Cannot insert a duplicate key into a unique index.
|
||||
<term>MATCH <replaceable class="parameter">matchtype</replaceable></term>
|
||||
<listitem>
|
||||
<para>
|
||||
The type of comparison to do between the table data. There are three
|
||||
types of matching, MATCH FULL, MATCH PARTIAL, and the unspecified match type
|
||||
used if no match type is specified.
|
||||
The type of comparison to do between the table data. There are
|
||||
three types of matching, MATCH FULL, MATCH PARTIAL, and the
|
||||
unspecified match type used if no match type is specified.
|
||||
MATCH PARTIAL is not
|
||||
currently supported.
|
||||
</para>
|
||||
</listitem>
|
||||
</varlistentry>
|
||||
@ -988,10 +973,10 @@ ERROR: Cannot insert a duplicate key into a unique index.
|
||||
deleted. There are the following actions.
|
||||
<variablelist>
|
||||
<varlistentry>
|
||||
<term>CASCADE</term>
|
||||
<term>NO ACTION</term>
|
||||
<listitem>
|
||||
<para>
|
||||
Delete any rows referencing the deleted row.
|
||||
Produce error if foreign key violated. This is the default.
|
||||
</para>
|
||||
</listitem>
|
||||
</varlistentry>
|
||||
@ -999,7 +984,15 @@ ERROR: Cannot insert a duplicate key into a unique index.
|
||||
<term>RESTRICT</term>
|
||||
<listitem>
|
||||
<para>
|
||||
Disallow deletion of rows being referenced.
|
||||
Same as NO ACTION.
|
||||
</para>
|
||||
</listitem>
|
||||
</varlistentry>
|
||||
<varlistentry>
|
||||
<term>CASCADE</term>
|
||||
<listitem>
|
||||
<para>
|
||||
Delete any rows referencing the deleted row.
|
||||
</para>
|
||||
</listitem>
|
||||
</varlistentry>
|
||||
@ -1019,14 +1012,6 @@ ERROR: Cannot insert a duplicate key into a unique index.
|
||||
</para>
|
||||
</listitem>
|
||||
</varlistentry>
|
||||
<varlistentry>
|
||||
<term>NO ACTION</term>
|
||||
<listitem>
|
||||
<para>
|
||||
Do nothing.
|
||||
</para>
|
||||
</listitem>
|
||||
</varlistentry>
|
||||
</variablelist>
|
||||
</para>
|
||||
</listitem>
|
||||
@ -1035,16 +1020,16 @@ ERROR: Cannot insert a duplicate key into a unique index.
|
||||
<term>ON UPDATE <replaceable class="parameter">action</replaceable></term>
|
||||
<listitem>
|
||||
<para>
|
||||
The action to do when a referenced column in the referenced table is being
|
||||
updated to a new value. If the row is updated, but the referenced column
|
||||
is not changed, no action is done. There are the following actions.
|
||||
The action to do when a referenced column in the referenced
|
||||
table is being updated to a new value. If the row is updated,
|
||||
but the referenced column is not changed, no action is done.
|
||||
There are the following actions.
|
||||
<variablelist>
|
||||
<varlistentry>
|
||||
<term>CASCADE</term>
|
||||
<term>NO ACTION</term>
|
||||
<listitem>
|
||||
<para>
|
||||
Update the value of the referencing column to the new value of the
|
||||
referenced column.
|
||||
Produce error if foreign key violated. This is the default.
|
||||
</para>
|
||||
</listitem>
|
||||
</varlistentry>
|
||||
@ -1052,7 +1037,16 @@ ERROR: Cannot insert a duplicate key into a unique index.
|
||||
<term>RESTRICT</term>
|
||||
<listitem>
|
||||
<para>
|
||||
Disallow update of row being referenced.
|
||||
Same as NO ACTION.
|
||||
</para>
|
||||
</listitem>
|
||||
</varlistentry>
|
||||
<varlistentry>
|
||||
<term>CASCADE</term>
|
||||
<listitem>
|
||||
<para>
|
||||
Update the value of the referencing column to the new value of the
|
||||
referenced column.
|
||||
</para>
|
||||
</listitem>
|
||||
</varlistentry>
|
||||
@ -1072,14 +1066,6 @@ ERROR: Cannot insert a duplicate key into a unique index.
|
||||
</para>
|
||||
</listitem>
|
||||
</varlistentry>
|
||||
<varlistentry>
|
||||
<term>NO ACTION</term>
|
||||
<listitem>
|
||||
<para>
|
||||
Do nothing.
|
||||
</para>
|
||||
</listitem>
|
||||
</varlistentry>
|
||||
</variablelist>
|
||||
</para>
|
||||
</listitem>
|
||||
@ -1089,8 +1075,10 @@ ERROR: Cannot insert a duplicate key into a unique index.
|
||||
<term> [ NOT ] DEFERRABLE </term>
|
||||
<listitem>
|
||||
<para>
|
||||
Tells the trigger manager whether this constraint may be
|
||||
deferred to the end of transaction.
|
||||
This controls whether the constraint can be deferred to the end
|
||||
of the transaction. If DEFERRABLE, SET CONSTRAINTS ALL DEFERRED
|
||||
will cause the foreign key to be checked only at the end of the
|
||||
transaction. NOT DEFERRABLE is the default.
|
||||
</para>
|
||||
</listitem>
|
||||
</varlistentry>
|
||||
@ -1101,22 +1089,20 @@ ERROR: Cannot insert a duplicate key into a unique index.
|
||||
<para>
|
||||
<replaceable class="parameter">checktime</replaceable> has two possible values
|
||||
which specify the default time to check the constraint.
|
||||
|
||||
<variablelist>
|
||||
<varlistentry>
|
||||
<term>DEFERRED</term>
|
||||
<listitem>
|
||||
<para>
|
||||
Check this constraint at the end of the transaction.
|
||||
Check constraint only at the end of the transaction.
|
||||
</para>
|
||||
</listitem>
|
||||
</varlistentry>
|
||||
|
||||
<varlistentry>
|
||||
<term>IMMEDIATE</term>
|
||||
<listitem>
|
||||
<para>
|
||||
Check this constraint after each statement.
|
||||
Check constraint after each statement. This is the default.
|
||||
</para>
|
||||
</listitem>
|
||||
</varlistentry>
|
||||
@ -1167,16 +1153,15 @@ ERROR: <replaceable class="parameter">name</replaceable> referential integrity
|
||||
<refsect3 id="R3-SQL-REFERENCES-3">
|
||||
<title>Description</title>
|
||||
<para>
|
||||
The REFERENCES column constraint specifies that a column of a
|
||||
table must only contain values which match against values
|
||||
in a referenced column of a referenced table.
|
||||
The REFERENCES column constraint specifies that a
|
||||
column of a table must only contain values which match against
|
||||
values in a referenced column of a referenced table.
|
||||
</para>
|
||||
<para>
|
||||
A value added to this column are matched against the
|
||||
values of the referenced table and referenced column using
|
||||
the given match type.
|
||||
In addition, when the referenced column data is changed,
|
||||
actions are run upon this column's matching data.
|
||||
A value added to this column are matched against the values of the
|
||||
referenced table and referenced column using the given match type.
|
||||
In addition, when the referenced column data is changed, actions
|
||||
are run upon this column's matching data.
|
||||
</para>
|
||||
</refsect3>
|
||||
|
||||
@ -1188,12 +1173,11 @@ ERROR: <replaceable class="parameter">name</replaceable> referential integrity
|
||||
Notes
|
||||
</title>
|
||||
<para>
|
||||
Currently <productname>Postgres</productname> only supports
|
||||
MATCH FULL and an unspecified match type.
|
||||
In addition, the referenced columns are supposed to be
|
||||
the columns of a UNIQUE constraint in the referenced table,
|
||||
however <productname>Postgres</productname> does not
|
||||
enforce this.
|
||||
Currently <productname>Postgres</productname> only supports MATCH
|
||||
FULL and an unspecified match type. In addition, the referenced
|
||||
columns are supposed to be the columns of a UNIQUE constraint in
|
||||
the referenced table, however <productname>Postgres</productname>
|
||||
does not enforce this.
|
||||
</para>
|
||||
</refsect3>
|
||||
</refsect2>
|
||||
@ -1281,14 +1265,6 @@ ERROR: <replaceable class="parameter">name</replaceable> referential integrity
|
||||
<member>FOREIGN KEY</member>
|
||||
</simplelist>
|
||||
</para>
|
||||
|
||||
<note>
|
||||
<para>
|
||||
<productname>Postgres</productname> now
|
||||
supports FOREIGN KEY
|
||||
integrity constraints
|
||||
</para>
|
||||
</note>
|
||||
</refsect2>
|
||||
|
||||
<refsect2 id="R2-SQL-UNIQUECLAUSE-4">
|
||||
@ -1354,10 +1330,11 @@ ERROR: <replaceable class="parameter">name</replaceable> referential integrity
|
||||
</title>
|
||||
|
||||
<para>
|
||||
The UNIQUE constraint specifies a rule that a group of one or
|
||||
more distinct columns of a table may contain only unique values.
|
||||
The behavior of the UNIQUE table constraint is the same as that for column
|
||||
constraints, with the additional capability to span multiple columns.
|
||||
The UNIQUE constraint specifies a rule that a group of one or more
|
||||
distinct columns of a table may contain only unique values. The
|
||||
behavior of the UNIQUE table constraint is the same as that for
|
||||
column constraints, with the additional capability to span multiple
|
||||
columns.
|
||||
</para>
|
||||
<para>
|
||||
See the section on the UNIQUE column constraint for more details.
|
||||
@ -1428,8 +1405,8 @@ CREATE TABLE distributors (
|
||||
<term>ERROR: Cannot insert a duplicate key into a unique index.</term>
|
||||
<listitem>
|
||||
<para>
|
||||
This occurs at run-time if one tries to insert a duplicate value into
|
||||
a column subject to a PRIMARY KEY constraint.
|
||||
This occurs at run-time if one tries to insert a duplicate
|
||||
value into a column subject to a PRIMARY KEY constraint.
|
||||
</para>
|
||||
</listitem>
|
||||
</varlistentry>
|
||||
@ -1475,14 +1452,13 @@ FOREIGN KEY ( <replaceable class="parameter">column</replaceable> [, ...] ) REFE
|
||||
[ MATCH <replaceable class="parameter">matchtype</replaceable> ]
|
||||
[ ON DELETE <replaceable class="parameter">action</replaceable> ]
|
||||
[ ON UPDATE <replaceable class="parameter">action</replaceable> ]
|
||||
[ [ NOT ] DEFERRABLE ]
|
||||
[ [ NOT ] DEFERRABLE ]
|
||||
[ INITIALLY <replaceable class="parameter">checktime</replaceable> ]
|
||||
</synopsis>
|
||||
<para>
|
||||
The REFERENCES constraint specifies a rule that a column
|
||||
value is checked against the values of another column.
|
||||
REFERENCES can also be specified as part of
|
||||
a FOREIGN KEY table constraint.
|
||||
The REFERENCES constraint specifies a rule that a column value is
|
||||
checked against the values of another column. REFERENCES can also be
|
||||
specified as part of a FOREIGN KEY table constraint.
|
||||
</para>
|
||||
|
||||
<refsect3 id="R3-SQL-REFERENCES-5">
|
||||
@ -1527,9 +1503,10 @@ FOREIGN KEY ( <replaceable class="parameter">column</replaceable> [, ...] ) REFE
|
||||
<term>MATCH <replaceable class="parameter">matchtype</replaceable></term>
|
||||
<listitem>
|
||||
<para>
|
||||
The type of comparison to do between the table data. There are three
|
||||
types of matching, MATCH FULL, MATCH PARTIAL, and the unspecified match type
|
||||
used if no match type is specified.
|
||||
The type of comparison to do between the table data. There are
|
||||
three types of matching, MATCH FULL, MATCH PARTIAL, and the
|
||||
unspecified match type used if no match type is specified.
|
||||
MATCH PARTIAL is not currently supported.
|
||||
</para>
|
||||
</listitem>
|
||||
</varlistentry>
|
||||
@ -1541,10 +1518,10 @@ FOREIGN KEY ( <replaceable class="parameter">column</replaceable> [, ...] ) REFE
|
||||
deleted. There are the following actions.
|
||||
<variablelist>
|
||||
<varlistentry>
|
||||
<term>CASCADE</term>
|
||||
<term>NO ACTION</term>
|
||||
<listitem>
|
||||
<para>
|
||||
Delete any rows referencing the deleted row.
|
||||
Produce error if foreign key violated. This is the default.
|
||||
</para>
|
||||
</listitem>
|
||||
</varlistentry>
|
||||
@ -1552,7 +1529,15 @@ FOREIGN KEY ( <replaceable class="parameter">column</replaceable> [, ...] ) REFE
|
||||
<term>RESTRICT</term>
|
||||
<listitem>
|
||||
<para>
|
||||
Disallow deletion of rows being referenced.
|
||||
Same as NO ACTION.
|
||||
</para>
|
||||
</listitem>
|
||||
</varlistentry>
|
||||
<varlistentry>
|
||||
<term>CASCADE</term>
|
||||
<listitem>
|
||||
<para>
|
||||
Delete any rows referencing the deleted row.
|
||||
</para>
|
||||
</listitem>
|
||||
</varlistentry>
|
||||
@ -1572,14 +1557,6 @@ FOREIGN KEY ( <replaceable class="parameter">column</replaceable> [, ...] ) REFE
|
||||
</para>
|
||||
</listitem>
|
||||
</varlistentry>
|
||||
<varlistentry>
|
||||
<term>NO ACTION</term>
|
||||
<listitem>
|
||||
<para>
|
||||
Do nothing.
|
||||
</para>
|
||||
</listitem>
|
||||
</varlistentry>
|
||||
</variablelist>
|
||||
</para>
|
||||
</listitem>
|
||||
@ -1588,16 +1565,16 @@ FOREIGN KEY ( <replaceable class="parameter">column</replaceable> [, ...] ) REFE
|
||||
<term>ON UPDATE <replaceable class="parameter">action</replaceable></term>
|
||||
<listitem>
|
||||
<para>
|
||||
The action to do when a referenced column in the referenced table is being
|
||||
updated to a new value. If the row is updated, but the referenced column
|
||||
is not changed, no action is done. There are the following actions.
|
||||
The action to do when a referenced column in the referenced
|
||||
table is being updated to a new value. If the row is updated,
|
||||
but the referenced column is not changed, no action is done.
|
||||
There are the following actions.
|
||||
<variablelist>
|
||||
<varlistentry>
|
||||
<term>CASCADE</term>
|
||||
<term>NO ACTION</term>
|
||||
<listitem>
|
||||
<para>
|
||||
Update the value of the referencing column to the new value of the
|
||||
referenced column.
|
||||
Produce error if foreign key violated. This is the default.
|
||||
</para>
|
||||
</listitem>
|
||||
</varlistentry>
|
||||
@ -1609,6 +1586,15 @@ FOREIGN KEY ( <replaceable class="parameter">column</replaceable> [, ...] ) REFE
|
||||
</para>
|
||||
</listitem>
|
||||
</varlistentry>
|
||||
<varlistentry>
|
||||
<term>CASCADE</term>
|
||||
<listitem>
|
||||
<para>
|
||||
Update the value of the referencing column to the new value
|
||||
of the referenced column.
|
||||
</para>
|
||||
</listitem>
|
||||
</varlistentry>
|
||||
<varlistentry>
|
||||
<term>SET NULL</term>
|
||||
<listitem>
|
||||
@ -1625,14 +1611,6 @@ FOREIGN KEY ( <replaceable class="parameter">column</replaceable> [, ...] ) REFE
|
||||
</para>
|
||||
</listitem>
|
||||
</varlistentry>
|
||||
<varlistentry>
|
||||
<term>NO ACTION</term>
|
||||
<listitem>
|
||||
<para>
|
||||
Do nothing.
|
||||
</para>
|
||||
</listitem>
|
||||
</varlistentry>
|
||||
</variablelist>
|
||||
</para>
|
||||
</listitem>
|
||||
@ -1641,8 +1619,10 @@ FOREIGN KEY ( <replaceable class="parameter">column</replaceable> [, ...] ) REFE
|
||||
<term> [ NOT ] DEFERRABLE </term>
|
||||
<listitem>
|
||||
<para>
|
||||
Tells the trigger manager whether this constraint may be
|
||||
deferred to the end of transaction.
|
||||
This controls whether the constraint can be deferred to the end
|
||||
of the transaction. If DEFERRABLE, SET CONSTRAINTS ALL DEFERRED
|
||||
will cause the foreign key to be checked only at the end of the
|
||||
transaction. NOT DEFERRABLE is the default.
|
||||
</para>
|
||||
</listitem>
|
||||
</varlistentry>
|
||||
@ -1650,22 +1630,23 @@ FOREIGN KEY ( <replaceable class="parameter">column</replaceable> [, ...] ) REFE
|
||||
<term>INITIALLY <replaceable class="parameter">checktime</replaceable></term>
|
||||
<listitem>
|
||||
<para>
|
||||
<replaceable class="parameter">checktime</replaceable> has two possible values
|
||||
which specify the default time to check the constraint.
|
||||
<replaceable class="parameter">checktime</replaceable> has two
|
||||
possible values which specify the default time to check the
|
||||
constraint.
|
||||
<variablelist>
|
||||
<varlistentry>
|
||||
<term>DEFERRED</term>
|
||||
<listitem>
|
||||
<para>
|
||||
Check this constraint at the end of the transaction.
|
||||
</para>
|
||||
</listitem>
|
||||
</varlistentry>
|
||||
<varlistentry>
|
||||
<term>IMMEDIATE</term>
|
||||
<listitem>
|
||||
<para>
|
||||
Check this constraint after each statement.
|
||||
Check constraint after each statement. This is the default.
|
||||
</para>
|
||||
</listitem>
|
||||
</varlistentry>
|
||||
<varlistentry>
|
||||
<term>DEFERRED</term>
|
||||
<listitem>
|
||||
<para>
|
||||
Check constraint only at the end of the transaction.
|
||||
</para>
|
||||
</listitem>
|
||||
</varlistentry>
|
||||
@ -1719,8 +1700,9 @@ ERROR: <replaceable class="parameter">name</replaceable> referential integrity
|
||||
</para>
|
||||
|
||||
<para>
|
||||
The FOREIGN KEY table constraint is similar to that for column constraints,
|
||||
with the additional capability of encompassing multiple columns.
|
||||
The FOREIGN KEY table constraint is similar to that for column
|
||||
constraints, with the additional capability of encompassing
|
||||
multiple columns.
|
||||
</para>
|
||||
<para>
|
||||
Refer to the section on the FOREIGN KEY column constraint for more
|
||||
@ -1886,10 +1868,10 @@ CREATE GLOBAL TEMPORARY TABLE <replaceable class="parameter">table</replaceable>
|
||||
constraints.
|
||||
</para>
|
||||
<para>
|
||||
The optional ON COMMIT clause of CREATE TEMPORARY TABLE
|
||||
specifies whether or not the temporary table should be emptied of
|
||||
rows whenever COMMIT is executed. If the ON COMMIT clause is
|
||||
omitted, the default option, ON COMMIT DELETE ROWS, is assumed.
|
||||
The optional ON COMMIT clause of CREATE TEMPORARY TABLE specifies
|
||||
whether or not the temporary table should be emptied of rows
|
||||
whenever COMMIT is executed. If the ON COMMIT clause is omitted, the
|
||||
default option, ON COMMIT DELETE ROWS, is assumed.
|
||||
</para>
|
||||
<para>
|
||||
To create a temporary table:
|
||||
@ -1936,10 +1918,10 @@ CREATE TEMPORARY TABLE actors (
|
||||
NULL clause
|
||||
</title>
|
||||
<para>
|
||||
The NULL "constraint" (actually a non-constraint)
|
||||
is a <productname>Postgres</productname> extension to SQL92
|
||||
is included for symmetry with the NOT NULL clause. Since it is the default
|
||||
for any column, its presence is simply noise.
|
||||
The NULL "constraint" (actually a non-constraint) is a
|
||||
<productname>Postgres</productname> extension to SQL92 is
|
||||
included for symmetry with the NOT NULL clause. Since it is the
|
||||
default for any column, its presence is simply noise.
|
||||
<synopsis>
|
||||
[ CONSTRAINT name ] NULL
|
||||
</synopsis>
|
||||
@ -2001,11 +1983,10 @@ the column. Not our problem...
|
||||
</para>
|
||||
<para>
|
||||
An assertion is a special type of integrity constraint and share
|
||||
the same namespace as other constraints.
|
||||
However, an assertion is not necessarily dependent on one
|
||||
particular base table as constraints are, so SQL-92 provides the
|
||||
CREATE ASSERTION statement as an alternate method for defining a
|
||||
constraint:
|
||||
the same namespace as other constraints. However, an assertion is
|
||||
not necessarily dependent on one particular base table as
|
||||
constraints are, so SQL-92 provides the CREATE ASSERTION statement
|
||||
as an alternate method for defining a constraint:
|
||||
</para>
|
||||
<synopsis>
|
||||
CREATE ASSERTION name CHECK ( condition )
|
||||
@ -2053,8 +2034,9 @@ CREATE ASSERTION name CHECK ( condition )
|
||||
<term>NOT DEFERRABLE</term>
|
||||
<listitem>
|
||||
<para>
|
||||
means that the Constraint must be checked for
|
||||
violation of its rule after the execution of every SQL statement.
|
||||
The constraint must be checked at the end of each statement.
|
||||
SET CONSTRAINTS ALL DEFERRED will have no effect on this type
|
||||
of constraint.
|
||||
</para>
|
||||
</listitem>
|
||||
</varlistentry>
|
||||
@ -2062,9 +2044,11 @@ CREATE ASSERTION name CHECK ( condition )
|
||||
<term>DEFERRABLE</term>
|
||||
<listitem>
|
||||
<para>
|
||||
means that checking of the Constraint may be deferred
|
||||
until some later time, but no later than the end of the current
|
||||
transaction.
|
||||
This controls whether the constraint can be deferred to the end
|
||||
of the transaction. If SET CONSTRAINTS ALL DEFERRED is used or
|
||||
the constraint is set to INITIALLY DEFERRED, this will cause
|
||||
the foreign key to be checked only at the end of the
|
||||
transaction.
|
||||
</para>
|
||||
</listitem>
|
||||
</varlistentry>
|
||||
@ -2079,9 +2063,8 @@ CREATE ASSERTION name CHECK ( condition )
|
||||
<term>INITIALLY IMMEDIATE</term>
|
||||
<listitem>
|
||||
<para>
|
||||
means that, as of the start of the transaction,
|
||||
the Constraint must be checked for violation of its rule after the
|
||||
execution of every SQL statement.
|
||||
Check constraint only at the end of the transaction. This
|
||||
is the default
|
||||
</para>
|
||||
</listitem>
|
||||
</varlistentry>
|
||||
@ -2089,9 +2072,8 @@ CREATE ASSERTION name CHECK ( condition )
|
||||
<term>INITIALLY DEFERRED</term>
|
||||
<listitem>
|
||||
<para>
|
||||
means that, as of the start of the transaction,
|
||||
checking of the Constraint may be deferred until some later time,
|
||||
but no later than the end of the current transaction.</para>
|
||||
Check constraint after each statement.
|
||||
</para>
|
||||
</listitem>
|
||||
</varlistentry>
|
||||
</variablelist>
|
||||
|
||||
Reference in New Issue
Block a user