How to Show Warnings in the MySQL Command-Line Tool

According to MySQL documentation SHOW WARNINGS shows the error, warning, and note messages that resulted from the last statement that generated messages in the current session. It shows nothing if the last statement used a table and generated no messages. So how to show warnings if you run in command line many queries using source command or stored procedure?

There are few ways to show warnings after every statement:
1. use --show-warnings option when you connect to database using mysql command.

mysql -u root --show-warnings

2. use warnings or \W commands in MySQL command-line.

mysql> warnings
Show warnings enabled.
mysql> \W
Show warnings enabled.

In order to disable warnings use nowarnings or \w commands in MySQL command-line.

mysql> nowarning
Show warnings disabled.
mysql> \w
Show warnings disabled.
mysql>

To view the list of all MySQL commands use help or ? commands in MySQL command-line.

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.
tee       (\T) Set outfile [to_outfile]. Append everything into given outfile.
use       (\u) Use another database. Takes database name as argument.
charset   (\C) Switch to another charset. Might be needed for processing binlog with multi-byte charsets.
warnings  (\W) Show warnings after every statement.
nowarning (\w) Don't show warnings after every statement.

For server side help, type 'help contents'

mysql>

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