The first is character count. The second is byte count. For the Latin characters the numbers are the same, but they’re not the same for Unicode and other encoding.
Using SUBSTR you can get a portion of a string.
SELECT SUBSTR(column_name, 1, 10) from table_name;
Using CONCAT method you can concatenate strings in MySQL.
CONCAT (string1, string2, string3)
Using following query you can find out all databases starting with “mysql”.
SHOW DATABASES LIKE ‘mysql%’;
You can change a table to InnoDB using following query.
ALTER TABLE table_name ENGINE innodb;
You can delete a column using following query.
ALTER TABLE table_name DROP column_name;
ALTER TABLE table_name CHANGE column_name column_name VARCHAR(100).