Merge pull request #347 from 16638112210/patch-1

这是PG英文手册本身的BUG，现已修复。
postgres/postgres@254a216

原则上这版的PG13中文手册应该以PG13.1英文手册为基准，但为了避免这个bug带来的麻烦，提前合并进来，同时反映到PG12。

Author: ChenHuajun

postgresql/doc/src/sgml/json.sgml

@@ -940,7 +940,7 @@ CREATE INDEX idxgintags ON api USING gin ((jdoc -> 'tags'));
 SELECT jdoc->'guid', jdoc->'name' FROM api WHERE jdoc @@ '$.tags[*] == "qui"';
 </programlisting>
 <programlisting>
-SELECT jdoc->'guid', jdoc->'name' FROM api WHERE jdoc @@ '$.tags[*] ? (@ == "qui")';
+SELECT jdoc->'guid', jdoc->'name' FROM api WHERE jdoc @? '$.tags[*] ? (@ == "qui")';
 </programlisting>
     GIN index extracts statements of following form out of
     <literal>jsonpath</literal>: <replaceable>accessors_chain</replaceable> = <replaceable>const</replaceable>.
@@ -956,7 +956,7 @@ ____________________________________________________________________________-->
 SELECT jdoc->'guid', jdoc->'name' FROM api WHERE jdoc @@ '$.tags[*] == "qui"';
 </programlisting>
 <programlisting>
-SELECT jdoc->'guid', jdoc->'name' FROM api WHERE jdoc @@ '$.tags[*] ? (@ == "qui")';
+SELECT jdoc->'guid', jdoc->'name' FROM api WHERE jdoc @? '$.tags[*] ? (@ == "qui")';
 </programlisting>
     GIN 索引从<literal>jsonpath</literal>中提取如下格式的语句： <replaceable>accessors_chain</replaceable> = <replaceable>const</replaceable>。
     存取器链可能由<literal>.key</literal><literal>[*]</literal>, 和 <literal>[<replaceable>index</replaceable>]</literal> 存取器组成。