diff options
Diffstat (limited to 'doc/src')
| -rw-r--r-- | doc/src/sgml/func.sgml | 37 |
1 files changed, 22 insertions, 15 deletions
diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml index 641b3b8f4e4..2f036015cc2 100644 --- a/doc/src/sgml/func.sgml +++ b/doc/src/sgml/func.sgml @@ -17034,8 +17034,7 @@ SELECT pg_type_is_visible('myschema.widget'::regtype); <row> <entry><literal><function>pg_get_serial_sequence(<parameter>table_name</parameter>, <parameter>column_name</parameter>)</function></literal></entry> <entry><type>text</type></entry> - <entry>get name of the sequence that a <type>serial</type>, <type>smallserial</type> or <type>bigserial</type> column - uses</entry> + <entry>get name of the sequence that a serial or identity column uses</entry> </row> <row> <entry><literal><function>pg_get_statisticsobjdef(<parameter>statobj_oid</parameter>)</function></literal></entry> @@ -17223,19 +17222,27 @@ SELECT pg_type_is_visible('myschema.widget'::regtype); <para> <function>pg_get_serial_sequence</function> returns the name of the sequence associated with a column, or NULL if no sequence is associated - with the column. The first input parameter is a table name with - optional schema, and the second parameter is a column name. Because - the first parameter is potentially a schema and table, it is not treated - as a double-quoted identifier, meaning it is lower cased by default, - while the second parameter, being just a column name, is treated as - double-quoted and has its case preserved. The function returns a value - suitably formatted for passing to sequence functions (see <xref - linkend="functions-sequence">). This association can be modified or - removed with <command>ALTER SEQUENCE OWNED BY</>. (The function - probably should have been called - <function>pg_get_owned_sequence</function>; its current name reflects the fact - that it's typically used with <type>serial</> or <type>bigserial</> - columns.) + with the column. If the column is an identity column, the associated + sequence is the sequence internally created for the identity column. For + columns created using one of the serial types + (<type>serial</type>, <type>smallserial</type>, <type>bigserial</type>), it + is the sequence created for that serial column definition. In the latter + case, this association can be modified or removed with <command>ALTER + SEQUENCE OWNED BY</>. (The function probably should have been called + <function>pg_get_owned_sequence</function>; its current name reflects the + fact that it has typically been used with <type>serial</> + or <type>bigserial</> columns.) The first input parameter is a table name + with optional schema, and the second parameter is a column name. Because + the first parameter is potentially a schema and table, it is not treated as + a double-quoted identifier, meaning it is lower cased by default, while the + second parameter, being just a column name, is treated as double-quoted and + has its case preserved. The function returns a value suitably formatted + for passing to sequence functions + (see <xref linkend="functions-sequence">). A typical use is in reading the + current value of a sequence for an identity or serial column, for example: +<programlisting> +SELECT currval(pg_get_serial_sequence('sometable', 'id')); +</programlisting> </para> <para> |