HELP statement returns online
information from the MySQL Reference Manual. Its proper operation
requires that the help tables in the
database be initialized with help topic information (see
Section 7.1.17, “Server-Side Help Support”).
HELP statement searches the
help tables for the given search string and displays the result of
the search. The search string is not case-sensitive.
The search string can contain the wildcard characters
_. 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
HELP statement does not require a
terminator such as
HELP statement understands several types of
At the most general level, use
contentsto retrieve a list of the top-level help categories:
For a list of topics in a given help category, such as
Data Types, use the category name:
HELP 'data types'
HELP 'ascii' HELP 'create table'
In other words, the search string matches a category, many topics, or a single topic. The following descriptions indicate the forms that the result set can take.
No match could be found for the search string.
Nothing found Please try to run 'help contents' for a list of all accessible topics
Result set containing a single row
This means that the search string yielded a hit for the help topic. The result includes the following items:
name: The topic name.
description: Descriptive help text for the topic.
example: One or more usage examples. (May be empty.)
Name: 'LOG' Description: Syntax: LOG(X), LOG(B,X) If called with one parameter, this function returns the natural logarithm of X. If X is less than or equal to 0.0E0, the function returns NULL and a warning "Invalid argument for logarithm" is reported. Returns NULL if X or B is NULL. The inverse of this function (when called with a single argument) is the EXP() function. URL: https://dev.mysql.com/doc/refman/8.0/en/mathematical-functions.html Examples: mysql> SELECT LOG(2); -> 0.69314718055995 mysql> SELECT LOG(-2); -> NULL
List of topics.
This means that the search string matched multiple help topics.
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: FLUSH SHOW SHOW BINARY LOG STATUS SHOW ENGINE SHOW FUNCTION STATUS SHOW MASTER STATUS SHOW PROCEDURE STATUS SHOW REPLICA STATUS SHOW SLAVE STATUS SHOW STATUS SHOW TABLE STATUS
List of topics.
A list is also displayed if the search string matches a category.
You asked for help about help category: "Functions" For more information, type 'help <item>', where <item> is one of the following categories: Aggregate Functions and Modifiers Bit Functions Cast Functions and Operators Comparison Operators Date and Time Functions Encryption Functions Enterprise Encryption Functions Flow Control Functions GROUP BY Functions and Modifiers GTID Information Functions Internal Functions Locking Functions Logical Operators Miscellaneous Functions Numeric Functions Performance Schema Functions Spatial Functions String Functions Window Functions XML