mysql> help search_string
        If you provide an argument to the help
        command, mysql uses it as a search string to
        access server-side help from the contents of the MySQL Reference
        Manual. The proper operation of this command requires that the
        help tables in the mysql database be
        initialized with help topic information (see
        Section 7.1.17, “Server-Side Help Support”).
      
If there is no match for the search string, the search fails:
mysql> help me
Nothing found
Please try to run 'help contents' for a list of all accessible topicsUse help contents to see a list of the help categories:
mysql> help contents
You asked for help about help category: "Contents"
For more information, type 'help <item>', where <item> is one of the
following categories:
   Account Management
   Administration
   Data Definition
   Data Manipulation
   Data Types
   Functions
   Functions and Modifiers for Use with GROUP BY
   Geographic Features
   Language Structure
   Plugins
   Storage Engines
   Stored Routines
   Table Maintenance
   Transactions
   TriggersIf the search string matches multiple items, mysql shows a list of matching topics:
mysql> help logs
Many help items for your request exist.
To make a more specific request, please type 'help <item>',
where <item> is one of the following topics:
   SHOW
   SHOW BINARY LOGS
   SHOW ENGINE
   SHOW LOGSUse a topic as the search string to see the help entry for that topic:
mysql> help show binary logs
Name: 'SHOW BINARY LOGS'
Description:
Syntax:
SHOW BINARY LOGS
Lists the binary log files on the server. This statement is used as
part of the procedure described in [purge-binary-logs], that shows how
to determine which logs can be purged.mysql> SHOW BINARY LOGS;
+---------------+-----------+-----------+
| Log_name      | File_size | Encrypted |
+---------------+-----------+-----------+
| binlog.000015 |    724935 | Yes       |
| binlog.000016 |    733481 | Yes       |
+---------------+-----------+-----------+
        The search string can contain the wildcard characters
        % and _. These have the
        same meaning as for pattern-matching operations performed with
        the LIKE operator. For example,
        HELP rep% returns a list of topics that begin
        with rep:
      
mysql> HELP rep%
Many help items for your request exist.
To make a more specific request, please type 'help <item>',
where <item> is one of the following
topics:
   REPAIR TABLE
   REPEAT FUNCTION
   REPEAT LOOP
   REPLACE
   REPLACE FUNCTION