diff options
Diffstat (limited to 'doc/src')
| -rw-r--r-- | doc/src/sgml/plpgsql.sgml | 21 |
1 files changed, 19 insertions, 2 deletions
diff --git a/doc/src/sgml/plpgsql.sgml b/doc/src/sgml/plpgsql.sgml index 11246aa6534..45d3e43ed14 100644 --- a/doc/src/sgml/plpgsql.sgml +++ b/doc/src/sgml/plpgsql.sgml @@ -946,8 +946,8 @@ PREPARE <replaceable>statement_name</replaceable>(integer, integer) AS SELECT $1 database engine. The expression must yield a single value (possibly a row value, if the variable is a row or record variable). The target variable can be a simple variable (optionally qualified with a block - name), a field of a row or record variable, or an element of an array - that is a simple variable or field. Equal (<literal>=</literal>) can be + name), a field of a row or record target, or an element or slice of + an array target. Equal (<literal>=</literal>) can be used instead of PL/SQL-compliant <literal>:=</literal>. </para> @@ -968,8 +968,25 @@ PREPARE <replaceable>statement_name</replaceable>(integer, integer) AS SELECT $1 <programlisting> tax := subtotal * 0.06; my_record.user_id := 20; +my_array[j] := 20; +my_array[1:3] := array[1,2,3]; +complex_array[n].realpart = 12.3; </programlisting> </para> + + <para> + It's useful to know that what follows the assignment operator is + essentially treated as a <literal>SELECT</literal> command; as long + as it returns a single row and column, it will work. Thus for example + one can write something like +<programlisting> +total_sales := sum(quantity) from sales; +</programlisting> + This provides an effect similar to the single-row <literal>SELECT + ... INTO</literal> syntax described in + <xref linkend="plpgsql-statements-sql-onerow"/>. However, that syntax + is more portable. + </para> </sect2> <sect2 id="plpgsql-statements-sql-noresult"> |