Mysql data type

INT (m), M is the tube of what use?
As an extension to the Ansi/iso SQL92 standard, MySQL also supports the integer types TINYINT, Mediumint, and BIGINT listed in the table above. Another extension is that MySQL supports arbitrarily specifying a display format for an integer value, which is achieved by following the type's basic keyword followed by a parenthesis (for example, INT (4)). This optional width specification is used to fill the left-hand display of values that are shorter than the width of the column when the value is displayed, rather than to limit the width of the values stored in the column, or to limit the number of digits that can be displayed for values that exceed the specified width of the column. When used with the optional extended attribute Zerofill, the default padding space is replaced by 0. For example, a column is defined as INT (5) Zerofill, and the inserted value 4 is retrieved when it is 00004. Note that if you store a larger value than the display width in an integer column, you may encounter problems when MySQL generates temporary tables for some complex junction (join), because in this case, MySQL trusts that all values are appropriate for the original column width.

Mysql data type