diff options
Diffstat (limited to 'doc/src')
| -rw-r--r-- | doc/src/sgml/ref/insert.sgml | 6 | ||||
| -rw-r--r-- | doc/src/sgml/ref/update.sgml | 37 |
2 files changed, 29 insertions, 14 deletions
diff --git a/doc/src/sgml/ref/insert.sgml b/doc/src/sgml/ref/insert.sgml index d2e29a8757..cbb0d279bd 100644 --- a/doc/src/sgml/ref/insert.sgml +++ b/doc/src/sgml/ref/insert.sgml @@ -1,5 +1,5 @@ <!-- -$Header: /cvsroot/pgsql/doc/src/sgml/ref/insert.sgml,v 1.22 2003/04/26 23:56:51 petere Exp $ +$Header: /cvsroot/pgsql/doc/src/sgml/ref/insert.sgml,v 1.23 2003/07/03 16:32:03 tgl Exp $ PostgreSQL documentation --> @@ -33,7 +33,7 @@ INSERT INTO <replaceable class="PARAMETER">table</replaceable> [ ( <replaceable <para> The columns in the target list may be listed in any order. Each column not present in the target list will be inserted - using a default value, either a declared default value + using a default value, either its declared default value or null. </para> @@ -77,7 +77,7 @@ INSERT INTO <replaceable class="PARAMETER">table</replaceable> [ ( <replaceable <term><literal>DEFAULT VALUES</literal></term> <listitem> <para> - All columns will be filled their default values. + All columns will be filled with their default values. </para> </listitem> </varlistentry> diff --git a/doc/src/sgml/ref/update.sgml b/doc/src/sgml/ref/update.sgml index 02cc07b0bd..1fe85b995e 100644 --- a/doc/src/sgml/ref/update.sgml +++ b/doc/src/sgml/ref/update.sgml @@ -1,5 +1,5 @@ <!-- -$Header: /cvsroot/pgsql/doc/src/sgml/ref/update.sgml,v 1.22 2003/06/25 04:19:24 momjian Exp $ +$Header: /cvsroot/pgsql/doc/src/sgml/ref/update.sgml,v 1.23 2003/07/03 16:32:12 tgl Exp $ PostgreSQL documentation --> @@ -28,7 +28,8 @@ UPDATE [ ONLY ] <replaceable class="PARAMETER">table</replaceable> SET <replacea <para> <command>UPDATE</command> changes the values of the specified columns in all rows that satisfy the condition. Only the columns to - be modified need appear as columns in the statement. + be modified need be mentioned in the statement; columns not explicitly + <literal>SET</> retain their previous values. </para> <para> @@ -41,8 +42,9 @@ UPDATE [ ONLY ] <replaceable class="PARAMETER">table</replaceable> SET <replacea <para> You must have the <literal>UPDATE</literal> privilege on the table to update it, as well as the <literal>SELECT</literal> - privilege to any table whose values are read in the <replaceable - class="parameter">condition</replaceable>. + privilege to any table whose values are read in the + <replaceable class="parameter">expression</replaceable>s or + <replaceable class="parameter">condition</replaceable>. </para> </refsect1> @@ -72,7 +74,8 @@ UPDATE [ ONLY ] <replaceable class="PARAMETER">table</replaceable> SET <replacea <term><replaceable class="PARAMETER">expression</replaceable></term> <listitem> <para> - An expression or value to assign to the column. + An expression to assign to the column. The expression may use the + old values of this and other columns in the table. </para> </listitem> </varlistentry> @@ -81,7 +84,8 @@ UPDATE [ ONLY ] <replaceable class="PARAMETER">table</replaceable> SET <replacea <term><literal>DEFAULT</literal></term> <listitem> <para> - This column will be filled with its default value. + Set the column to its default value (which will be NULL if no + specific default expression has been assigned to it). </para> </listitem> </varlistentry> @@ -91,7 +95,7 @@ UPDATE [ ONLY ] <replaceable class="PARAMETER">table</replaceable> SET <replacea <listitem> <para> A list of table expressions, allowing columns from other tables - to appear in the <literal>WHERE</> condition. + to appear in the <literal>WHERE</> condition and the update expressions. </para> </listitem> </varlistentry> @@ -100,9 +104,9 @@ UPDATE [ ONLY ] <replaceable class="PARAMETER">table</replaceable> SET <replacea <term><replaceable class="PARAMETER">condition</replaceable></term> <listitem> <para> - A value expression that returns a value of type - <type>boolean</type> that determines the rows which are to be - updated. + An expression that returns a value of type <type>boolean</type>. + Only rows for which this expression returns <literal>true</> + will be updated. </para> </listitem> </varlistentry> @@ -135,9 +139,20 @@ UPDATE [ ONLY ] <replaceable class="PARAMETER">table</replaceable> SET <replacea column <structfield>kind</> of the table <literal>films</literal>: <programlisting> -UPDATE filme SET kind = 'Dramatic' WHERE kind = 'Drama'; +UPDATE films SET kind = 'Dramatic' WHERE kind = 'Drama'; </programlisting> </para> + + <para> + Adjust temperature entries and reset precipitation to its default + value in one row of the table <literal>weather</literal>: + +<programlisting> +UPDATE weather SET temp_lo = temp_lo+1, temp_hi = temp_lo+15, prcp = DEFAULT + WHERE city = 'San Francisco' AND date = '2003-07-03'; +</programlisting> + </para> + </refsect1> <refsect1> |