database/postgres
1
0
Fork 0
mirror of https://github.com/postgres/postgres.git synced 2025-08-31 17:02:12 +03:00
Code Activity

In plpgsql, allow %TYPE and %ROWTYPE to be followed by array decoration.

Browse Source 
This provides the useful ability to declare a variable that is an array
of the type of some other variable or some table column.

Quan Zongliang, Pavel Stehule

Discussion: https://postgr.es/m/ec4523e1-9e7e-f3ef-f9ce-bafd680ad6f6@yeah.net
This commit is contained in:
Tom Lane
2024-01-04 15:24:15 -05:00
parent 5d06e99a3c
commit 5e8674dc83
6 changed files with 261 additions and 32 deletions
Download Patch File Download Diff File Expand all files Collapse all files

29
doc/src/sgml/plpgsql.sgml
View File

@@ -675,12 +675,14 @@ DECLARE
<title>Copying Types</title>
<synopsis>
<replaceable>variable</replaceable>%TYPE
<replaceable>name</replaceable> <replaceable>table</replaceable>.<replaceable>column</replaceable>%TYPE
<replaceable>name</replaceable> <replaceable>variable</replaceable>%TYPE
</synopsis>
<para>
<literal>%TYPE</literal> provides the data type of a variable or
table column. You can use this to declare variables that will hold
<literal>%TYPE</literal> provides the data type of a table column
or a previously-declared <application>PL/pgSQL</application>
variable. You can use this to declare variables that will hold
database values. For example, let's say you have a column named
<literal>user_id</literal> in your <literal>users</literal>
table. To declare a variable with the same data type as
@@ -690,6 +692,21 @@ user_id users.user_id%TYPE;
</programlisting>
</para>
<para>
It is also possible to write array decoration
after <literal>%TYPE</literal>, thereby creating a variable that holds
an array of the referenced type:
<programlisting>
user_ids users.user_id%TYPE[];
user_ids users.user_id%TYPE ARRAY[4]; -- equivalent to the above
</programlisting>
Just as when declaring table columns that are arrays, it doesn't
matter whether you write multiple bracket pairs or specific array
dimensions: <productname>PostgreSQL</productname> treats all arrays of
a given element type as the same type, regardless of dimensionality.
(See <xref linkend="arrays-declaration"/>.)
</para>
<para>
By using <literal>%TYPE</literal> you don't need to know the data
type of the structure you are referencing, and most importantly,
@@ -739,6 +756,12 @@ user_id users.user_id%TYPE;
<literal>%ROWTYPE</literal> is more portable.)
</para>
<para>
As with <literal>%TYPE</literal>, <literal>%ROWTYPE</literal> can be
followed by array decoration to declare a variable that holds an array
of the referenced composite type.
</para>
<para>
Parameters to a function can be
composite types (complete table rows). In that case, the