diff options
| -rw-r--r-- | doc/src/sgml/func.sgml | 114 |
1 files changed, 52 insertions, 62 deletions
diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml index 90169a0ce72..034fecc3a19 100644 --- a/doc/src/sgml/func.sgml +++ b/doc/src/sgml/func.sgml @@ -3511,54 +3511,6 @@ repeat('Pg', 4) <returnvalue>PgPgPgPg</returnvalue> <row> <entry role="func_table_entry"><para role="func_signature"> <indexterm> - <primary>strpos</primary> - </indexterm> - <function>strpos</function> ( <parameter>string</parameter> <type>text</type>, <parameter>substring</parameter> <type>text</type> ) - <returnvalue>integer</returnvalue> - </para> - <para> - Returns first starting index of the specified <parameter>substring</parameter> - within <parameter>string</parameter>, or zero if it's not present. - (Same as <literal>position(<parameter>substring</parameter> in - <parameter>string</parameter>)</literal>, but note the reversed - argument order.) - </para> - <para> - <literal>strpos('high', 'ig')</literal> - <returnvalue>2</returnvalue> - </para></entry> - </row> - - <row> - <entry role="func_table_entry"><para role="func_signature"> - <indexterm> - <primary>substr</primary> - </indexterm> - <function>substr</function> ( <parameter>string</parameter> <type>text</type>, <parameter>start</parameter> <type>integer</type> <optional>, <parameter>count</parameter> <type>integer</type> </optional> ) - <returnvalue>text</returnvalue> - </para> - <para> - Extracts the substring of <parameter>string</parameter> starting at - the <parameter>start</parameter>'th character, - and extending for <parameter>count</parameter> characters if that is - specified. (Same - as <literal>substring(<parameter>string</parameter> - from <parameter>start</parameter> - for <parameter>count</parameter>)</literal>.) - </para> - <para> - <literal>substr('alphabet', 3)</literal> - <returnvalue>phabet</returnvalue> - </para> - <para> - <literal>substr('alphabet', 3, 2)</literal> - <returnvalue>ph</returnvalue> - </para></entry> - </row> - - <row> - <entry role="func_table_entry"><para role="func_signature"> - <indexterm> <primary>starts_with</primary> </indexterm> <function>starts_with</function> ( <parameter>string</parameter> <type>text</type>, <parameter>prefix</parameter> <type>text</type> ) @@ -3576,7 +3528,7 @@ repeat('Pg', 4) <returnvalue>PgPgPgPg</returnvalue> <row> <entry role="func_table_entry"><para role="func_signature"> - <indexterm> + <indexterm id="function-string-to-array"> <primary>string_to_array</primary> </indexterm> <function>string_to_array</function> ( <parameter>string</parameter> <type>text</type>, <parameter>delimiter</parameter> <type>text</type> <optional>, <parameter>null_string</parameter> <type>text</type> </optional> ) @@ -3594,6 +3546,7 @@ repeat('Pg', 4) <returnvalue>PgPgPgPg</returnvalue> If <parameter>null_string</parameter> is supplied and is not <literal>NULL</literal>, fields matching that string are replaced by <literal>NULL</literal>. + See also <link linkend="function-array-to-string"><function>array_to_string</function></link>. </para> <para> <literal>string_to_array('xx~~yy~~zz', '~~', 'yy')</literal> @@ -3636,6 +3589,54 @@ repeat('Pg', 4) <returnvalue>PgPgPgPg</returnvalue> <row> <entry role="func_table_entry"><para role="func_signature"> <indexterm> + <primary>strpos</primary> + </indexterm> + <function>strpos</function> ( <parameter>string</parameter> <type>text</type>, <parameter>substring</parameter> <type>text</type> ) + <returnvalue>integer</returnvalue> + </para> + <para> + Returns first starting index of the specified <parameter>substring</parameter> + within <parameter>string</parameter>, or zero if it's not present. + (Same as <literal>position(<parameter>substring</parameter> in + <parameter>string</parameter>)</literal>, but note the reversed + argument order.) + </para> + <para> + <literal>strpos('high', 'ig')</literal> + <returnvalue>2</returnvalue> + </para></entry> + </row> + + <row> + <entry role="func_table_entry"><para role="func_signature"> + <indexterm> + <primary>substr</primary> + </indexterm> + <function>substr</function> ( <parameter>string</parameter> <type>text</type>, <parameter>start</parameter> <type>integer</type> <optional>, <parameter>count</parameter> <type>integer</type> </optional> ) + <returnvalue>text</returnvalue> + </para> + <para> + Extracts the substring of <parameter>string</parameter> starting at + the <parameter>start</parameter>'th character, + and extending for <parameter>count</parameter> characters if that is + specified. (Same + as <literal>substring(<parameter>string</parameter> + from <parameter>start</parameter> + for <parameter>count</parameter>)</literal>.) + </para> + <para> + <literal>substr('alphabet', 3)</literal> + <returnvalue>phabet</returnvalue> + </para> + <para> + <literal>substr('alphabet', 3, 2)</literal> + <returnvalue>ph</returnvalue> + </para></entry> + </row> + + <row> + <entry role="func_table_entry"><para role="func_signature"> + <indexterm> <primary>to_ascii</primary> </indexterm> <function>to_ascii</function> ( <parameter>string</parameter> <type>text</type> ) @@ -18452,7 +18453,7 @@ SELECT NULLIF(value, '(none)') ... <row> <entry role="func_table_entry"><para role="func_signature"> - <indexterm> + <indexterm id="function-array-to-string"> <primary>array_to_string</primary> </indexterm> <function>array_to_string</function> ( <parameter>array</parameter> <type>anyarray</type>, <parameter>delimiter</parameter> <type>text</type> <optional>, <parameter>null_string</parameter> <type>text</type> </optional> ) @@ -18465,6 +18466,7 @@ SELECT NULLIF(value, '(none)') ... If <parameter>null_string</parameter> is given and is not <literal>NULL</literal>, then <literal>NULL</literal> array entries are represented by that string; otherwise, they are omitted. + See also <link linkend="function-string-to-array"><function>string_to_array</function></link>. </para> <para> <literal>array_to_string(ARRAY[1, 2, 3, NULL, 5], ',', '*')</literal> @@ -18584,18 +18586,6 @@ SELECT NULLIF(value, '(none)') ... </tgroup> </table> - <note> - <para> - There are two differences in the behavior of <function>string_to_array</function> - from pre-9.1 versions of <productname>PostgreSQL</productname>. - First, it will return an empty (zero-element) array rather - than <literal>NULL</literal> when the input string is of zero length. - Second, if the delimiter string is <literal>NULL</literal>, the function - splits the input into individual characters, rather than - returning <literal>NULL</literal> as before. - </para> - </note> - <para> See also <xref linkend="functions-aggregate"/> about the aggregate function <function>array_agg</function> for use with arrays. |