diff options
Diffstat (limited to 'doc/src/sgml/ref/update.sgml')
| -rw-r--r-- | doc/src/sgml/ref/update.sgml | 22 |
1 files changed, 11 insertions, 11 deletions
diff --git a/doc/src/sgml/ref/update.sgml b/doc/src/sgml/ref/update.sgml index f58dcd8877b..07958e74471 100644 --- a/doc/src/sgml/ref/update.sgml +++ b/doc/src/sgml/ref/update.sgml @@ -27,7 +27,7 @@ UPDATE [ ONLY ] <replaceable class="parameter">table_name</replaceable> [ * ] [ ( <replaceable class="parameter">column_name</replaceable> [, ...] ) = [ ROW ] ( { <replaceable class="parameter">expression</replaceable> | DEFAULT } [, ...] ) | ( <replaceable class="parameter">column_name</replaceable> [, ...] ) = ( <replaceable class="parameter">sub-SELECT</replaceable> ) } [, ...] - [ FROM <replaceable class="parameter">from_list</replaceable> ] + [ FROM <replaceable class="parameter">from_item</replaceable> [, ...] ] [ WHERE <replaceable class="parameter">condition</replaceable> | WHERE CURRENT OF <replaceable class="parameter">cursor_name</replaceable> ] [ RETURNING * | <replaceable class="parameter">output_expression</replaceable> [ [ AS ] <replaceable class="parameter">output_name</replaceable> ] [, ...] ] </synopsis> @@ -164,17 +164,17 @@ UPDATE [ ONLY ] <replaceable class="parameter">table_name</replaceable> [ * ] [ </varlistentry> <varlistentry> - <term><replaceable class="parameter">from_list</replaceable></term> + <term><replaceable class="parameter">from_item</replaceable></term> <listitem> <para> - A list of table expressions, allowing columns from other tables - to appear in the <literal>WHERE</literal> condition and the update - expressions. This is similar to the list of tables that can be - specified in the <xref linkend="sql-from" - endterm="sql-from-title"/> of a <command>SELECT</command> - statement. Note that the target table must not appear in the - <replaceable>from_list</replaceable>, unless you intend a self-join (in which - case it must appear with an alias in the <replaceable>from_list</replaceable>). + A table expression allowing columns from other tables to appear in + the <literal>WHERE</literal> condition and update expressions. This + uses the same syntax as the <xref linkend="sql-from" + endterm="sql-from-title"/> of a <command>SELECT</command> statement; + for example, an alias for the table name can be specified. Do not + repeat the target table as a <replaceable>from_item</replaceable> + unless you intend a self-join (in which case it must appear with + an alias in the <replaceable>from_item</replaceable>). </para> </listitem> </varlistentry> @@ -264,7 +264,7 @@ UPDATE <replaceable class="parameter">count</replaceable> <para> When a <literal>FROM</literal> clause is present, what essentially happens is that the target table is joined to the tables mentioned in the - <replaceable>from_list</replaceable>, and each output row of the join + <replaceable>from_item</replaceable> list, and each output row of the join represents an update operation for the target table. When using <literal>FROM</literal> you should ensure that the join produces at most one output row for each row to be modified. In |