create/drop/Alter user in MySQL database?

 The following is the basic syntax to create a new user in MySQL:

CREATE USER testmysqlusr IDENTIFIED BY 'petcom123';  

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mysql> CREATE USER testmysqlusr IDENTIFIED BY 'petcom123';

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CREATE USER testmysqlusr IDENTIFIED BY 'petcom123'

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Query OK, 0 rows affected (0.04 sec)

ALTER USER 'testmysqlusr'@'localhost' IDENTIFIED BY 'macd123'; 

Query OK, 0 rows affected (0.04 sec)

mysql>SHOW GRANTS FOR 'testmysqlusr'@'localhost';

mysql> SHOW GRANTS FOR 'testmysqlusr'@'localhost';

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SHOW GRANTS FOR 'testmysqlusr'@'localhost'

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ERROR 1141 (42000): There is no such grant defined for user 'testmysqlusr' on host 'localhost'

mysql>

mysql> drop user testmysqlusr;

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drop user testmysqlusr

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Query OK, 0 rows affected (0.01 sec)