Add string functions: concat(), concat_ws(), left(), right(), and reverse().

Pavel Stehule, reviewed by me.

1 files changed, 84 insertions, 1 deletions

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index ae5139cb9eb..66f72f32143 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -1,4 +1,4 @@
-<!-- $PostgreSQL: pgsql/doc/src/sgml/func.sgml,v 1.529 2010/08/17 04:37:20 petere Exp $ -->
+<!-- $PostgreSQL: pgsql/doc/src/sgml/func.sgml,v 1.530 2010/08/24 06:30:43 itagaki Exp $ -->
 
  <chapter id="functions">
   <title>Functions and Operators</title>
@@ -1251,6 +1251,12 @@
     <primary>chr</primary>
    </indexterm>
    <indexterm>
+    <primary>concat</primary>
+   </indexterm>
+   <indexterm>
+    <primary>concat_ws</primary>
+   </indexterm>
+   <indexterm>
     <primary>convert</primary>
    </indexterm>
    <indexterm>
@@ -1269,6 +1275,9 @@
     <primary>initcap</primary>
    </indexterm>
    <indexterm>
+    <primary>left</primary>
+   </indexterm>
+   <indexterm>
     <primary>lpad</primary>
    </indexterm>
    <indexterm>
@@ -1296,6 +1305,12 @@
     <primary>replace</primary>
    </indexterm>
    <indexterm>
+    <primary>reverse</primary>
+   </indexterm>
+   <indexterm>
+    <primary>right</primary>
+   </indexterm>
+   <indexterm>
     <primary>rpad</primary>
    </indexterm>
    <indexterm>
@@ -1376,6 +1391,34 @@
 
       <row>
        <entry>
+        <literal><function>concat</function>(<parameter>str</parameter> <type>"any"</type>
+         [, <parameter>str</parameter> <type>"any"</type> [, ...] ])</literal>
+       </entry>
+       <entry><type>text</type></entry>
+       <entry>
+        Concatenate all arguments. NULL arguments are ignored.
+       </entry>
+       <entry><literal>concat('abcde', 2, NULL, 22)</literal></entry>
+       <entry><literal>abcde222</literal></entry>
+      </row>
+
+      <row>
+       <entry>
+        <literal><function>concat_ws</function>(<parameter>sep</parameter> <type>text</type>,
+        <parameter>str</parameter> <type>"any"</type>
+        [, <parameter>str</parameter> <type>"any"</type> [, ...] ])</literal>
+       </entry>
+       <entry><type>text</type></entry>
+       <entry>
+        Concatenate all but first arguments with separators. The first
+        parameter is used as a separator. NULL arguments are ignored.
+       </entry>
+       <entry><literal>concat_ws(',', 'abcde', 2, NULL, 22)</literal></entry>
+       <entry><literal>abcde,2,22</literal></entry>
+      </row>
+
+      <row>
+       <entry>
         <literal><function>convert</function>(<parameter>string</parameter> <type>bytea</type>,
         <parameter>src_encoding</parameter> <type>name</type>,
         <parameter>dest_encoding</parameter> <type>name</type>)</literal>
@@ -1466,6 +1509,20 @@
       </row>
 
       <row>
+       <entry>
+        <literal><function>left</function>(<parameter>str</parameter> <type>text</type>,
+        <parameter>n</parameter> <type>int</type>)</literal>
+       </entry>
+       <entry><type>text</type></entry>
+       <entry>
+        Return first <replaceable>n</> characters in the string. When <replaceable>n</>
+        is negative, return all but last |<replaceable>n</>| characters.
+        </entry>
+       <entry><literal>left('abcde', 2)</literal></entry>
+       <entry><literal>ab</literal></entry>
+      </row>
+
+      <row>
        <entry><literal><function>length</function>(<parameter>string</parameter>)</literal></entry>
        <entry><type>int</type></entry>
        <entry>
@@ -1680,6 +1737,32 @@
 
       <row>
        <entry>
+        <literal><function>reverse</function>(<parameter>str</parameter>)</literal>
+       </entry>
+       <entry><type>text</type></entry>
+       <entry>
+        Return reversed string.
+       </entry>
+       <entry><literal>reverse('abcde')</literal></entry>
+       <entry><literal>edcba</literal></entry>
+      </row>
+
+      <row>
+       <entry>
+        <literal><function>right</function>(<parameter>str</parameter> <type>text</type>,
+         <parameter>n</parameter> <type>int</type>)</literal>
+       </entry>
+       <entry><type>text</type></entry>
+       <entry>
+        Return last <replaceable>n</> characters in the string. When <replaceable>n</>
+        is negative, return all but first |<replaceable>n</>| characters.
+       </entry>
+       <entry><literal>right('abcde', 2)</literal></entry>
+       <entry><literal>de</literal></entry>
+      </row>
+
+      <row>
+       <entry>
         <literal><function>rpad</function>(<parameter>string</parameter> <type>text</type>,
         <parameter>length</parameter> <type>int</type>
         <optional>, <parameter>fill</parameter> <type>text</type></optional>)</literal>