How to show mysql client commands after login?

Question

With --help, -? or -I, I could show mysql client options before login as shown below. *The doc explains it more:

mysql --help

Or:

mysql -?

Or:

mysql -I

mysql --help
...
Usage: C:\Program Files\MySQL\MySQL Server 8.0\bin\mysql.exe [OPTIONS] [database]
  -?, --help          Display this help and exit.
  -I, --help          Synonym for -?
  --auto-rehash       Enable automatic rehashing. One doesn't need to use
                      'rehash' to get table and field completion, but startup
                      and reconnecting may take a longer time. Disable with
                      --disable-auto-rehash.
                      (Defaults to on; use --skip-auto-rehash to disable.)
  -A, --no-auto-rehash
                      No automatic rehashing. One has to use 'rehash' to get
                      table and field completion. This gives a quicker start of
                      mysql and disables rehashing on reconnect.
  --auto-vertical-output
                      Automatically switch to vertical output mode if the
                      result is wider than the terminal width.
  -B, --batch         Don't use history file. Disable interactive behavior.
                      (Enables --silent.)
...

Now, how can I show mysql client commands after login like use, exit, clear, delimiter, etc?

Answer 1

You can use these commands to show mysql client commands as shown below. *The doc explains it more:

help

help;

HELP

HELP;

\h

\h;

\?

\?;

*Adding one or more characters like apple just after \h or \? as shown below still works:

\happle

Or:

\?apple

Then, you can show mysql client commands as shown below:

mysql> help
...
List of all MySQL commands:
Note that all text commands must be first on line and end with ';'
?         (\?) Synonym for `help'.
clear     (\c) Clear the current input statement.
connect   (\r) Reconnect to the server. Optional arguments are db and host.
delimiter (\d) Set statement delimiter.
ego       (\G) Send command to mysql server, display result vertically.
exit      (\q) Exit mysql. Same as quit.
go        (\g) Send command to mysql server.
help      (\h) Display this help.
notee     (\t) Don't write into outfile.
print     (\p) Print current command.
prompt    (\R) Change your mysql prompt.
quit      (\q) Quit mysql.
rehash    (\#) Rebuild completion hash.
source    (\.) Execute an SQL script file. Takes a file name as an argument.
status    (\s) Get status information from the server.
system    (\!) Execute a system shell command.
tee       (\T) Set outfile [to_outfile]. Append everything into given outfile.
use       (\u) Use another database. Takes database name as argument.
...

In addition, you can show mysql client server-side help with contents as shown below. *The categories are listed and the doc explains it more:

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
   Components
   Compound Statements
   Contents
   Data Definition
   Data Manipulation
   Data Types
   Functions
   Geographic Features
   Help Metadata
   Language Structure
   Loadable Functions
   Plugins
   Prepared Statements
   Replication Statements
   Storage Engines
   Table Maintenance
   Transactions
   Utility

Then, you can show one of the categories Data Manipulation as shown below. *The topics are listed:

mysql> help Data Manipulation
You asked for help about help category: "Data Manipulation"
For more information, type 'help <item>', where <item> is one of the following
topics:
   CALL
   DELETE
   DO
   DUAL
   EXCEPT
   HANDLER
   IMPORT TABLE
   INSERT
   INSERT DELAYED
   INSERT SELECT
   INTERSECT
   JOIN
   LOAD DATA
   LOAD XML
   PARENTHESIZED QUERY EXPRESSIONS
   REPLACE
   SELECT
   TABLE
   UNION
   UPDATE
   VALUES STATEMENT

Then, you can show one of the topics SELECT of Data Manipulation as shown below. *The explanation is shown:

mysql> help SELECT 
Name: 'SELECT'
Description:
Syntax:
SELECT
    [ALL | DISTINCT | DISTINCTROW ]
    [HIGH_PRIORITY]
    [STRAIGHT_JOIN]
    [SQL_SMALL_RESULT] [SQL_BIG_RESULT] [SQL_BUFFER_RESULT]
    [SQL_NO_CACHE] [SQL_CALC_FOUND_ROWS]
    select_expr [, select_expr] ...
    [into_option]
    [FROM table_references
      [PARTITION partition_list]]
    [WHERE where_condition]
    [GROUP BY {col_name | expr | position}, ... [WITH ROLLUP]]
    [HAVING where_condition]
    [WINDOW window_name AS (window_spec)
        [, window_name AS (window_spec)] ...]
    [ORDER BY {col_name | expr | position}
      [ASC | DESC], ... [WITH ROLLUP]]
    [LIMIT {[offset,] row_count | row_count OFFSET offset}]
    [into_option]
    [FOR {UPDATE | SHARE}
        [OF tbl_name [, tbl_name] ...]
        [NOWAIT | SKIP LOCKED]
      | LOCK IN SHARE MODE]
    [into_option]
...