mysql.help_topic Table

mysql.help_topic is one of the four tables used by the HELP command. It is populated when the server is installed by the fill_help_table.sql script. The other help tables are help_relation, help_category and help_keyword.

MariaDB starting with 10.4

In MariaDB 10.4 and later, this table uses the Aria storage engine.

MariaDB until 10.3

In MariaDB 10.3 and before, this table uses the MyISAM storage engine.

The mysql.help_topic table contains the following fields:

FieldTypeNullKeyDefaultDescription
help_topic_idint(10) unsignedNOPRINULL
namechar(64)NOUNINULL
help_category_idsmallint(5) unsignedNONULL
descriptiontextNONULL
exampletextNONULL
urlchar(128)NONULL

Example

SELECT * FROM help_topic\G;
...
*************************** 508. row ***************************
   help_topic_id: 507
            name: FIND_IN_SET
help_category_id: 37
     description: Syntax:
FIND_IN_SET(str,strlist)

Returns a value in the range of 1 to N if the string str is in the
string list strlist consisting of N substrings. A string list is a
string composed of substrings separated by "," characters. If the first
argument is a constant string and the second is a column of type SET,
the FIND_IN_SET() function is optimized to use bit arithmetic. Returns
0 if str is not in strlist or if strlist is the empty string. Returns
NULL if either argument is NULL. This function does not work properly
if the first argument contains a comma (",") character.

URL: http://dev.mysql.com/doc/refman/5.5/en/string-functions.html


         example: mysql> SELECT FIND_IN_SET('b','a,b,c,d');
        -> 2

             url: http://dev.mysql.com/doc/refman/5.5/en/string-functions.html

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