MySQL supports a number of column types, which may be grouped into three categories: numeric types, date and time types, and string (character) types. This section first gives an overview of the types available.
TINYINT
Use for : A very small integer
The signed range is –128 to 127. The unsigned range is 0 to 255.
SMALLINT
Use for : A small integer
The signed range is –32768 to 32767. The unsigned range is 0 to 65535
MEDIUMINT
Use for : A medium-size integer
The signed range is –8388608 to 8388607. The unsigned range is 0 to 16777215
INT or INTEGER
Use for : A normal-size integer
The signed range is –2147483648 to 2147483647. The unsigned range is 0 to 4294967295
BIGINT
Use for : A large integer
The signed range is –9223372036854775808 to 9223372036854775807. The unsigned range is 0 to 18446744073709551615
FLOAT
Use for : A small (single-precision) floating-point number. Cannot be unsigned
Ranges are –3.402823466E+38 to –1.175494351E-38, 0 and 1.175494351E-38 to 3.402823466E+38. If the number of Decimals is not set or <= 24 it is a single-precision floating point number
DOUBLE, DOUBLE PRECISION, REAL
Use for : A normal-size (double-precision) floating-point number. Cannot be unsigned
Ranges are -1.7976931348623157E+308 to -2.2250738585072014E-308, 0 and 2.2250738585072014E-308 to 1.7976931348623157E+308. If the number of Decimals is not set or 25 <= Decimals <= 53 stands for a double-precision floating point number
DECIMAL, NUMERIC
Use for : An unpacked floating-point number. Cannot be unsigned
Behaves like a CHAR column: “unpacked” means the number is stored as a string, using one character for each digit of the value. The decimal point, and, for negative numbers, the ‘-‘ sign is not counted in Length. If Decimals is 0, values will have no decimal point or fractional part. The maximum range of DECIMAL values is the same as for DOUBLE, but the actual range for a given DECIMAL column may be constrained by the choice of Length and Decimals. If Decimals is left out it’s set to 0. If Length is left out it’s set to 10. Note that in MySQL 3.22 the Length includes the sign and the decimal point
DATE
Use for : A date
The supported range is ‘1000-01-01’ to ‘9999-12-31’. MySQL displays DATE values in ‘YYYY-MM-DD’ format
DATETIME
Use for : A date and time combination
The supported range is ‘1000-01-01 00:00:00’ to ‘9999-12-31 23:59:59’. MySQL displays DATETIME values in ‘YYYY-MM-DD HH:MM:SS’ format
TIMESTAMP
Use for : A timestamp
The range is ‘1970-01-01 00:00:00’ to ’2038-01-19 03:14:07′. MySQL displays TIMESTAMP values in YYYYMMDDHHMMSS, YYMMDDHHMMSS, YYYYMMDD or YYMMDD format, depending on whether M is 14 (or missing), 12, 8 or 6, but allows you to assign values to TIMESTAMP columns using either strings or numbers. A TIMESTAMP column is useful for recording the date and time of an INSERT or UPDATE operation because it is automatically set to the date and time of the most recent operation if you don’t give it a value yourself
TIME
Use for : A time
The range is ‘-838:59:59’ to ‘838:59:59’. MySQL displays TIME values in ‘HH:MM:SS’ format, but allows you to assign values to TIME columns using either strings or numbers
YEAR
Use for : A year in 2- or 4- digit formats (default is 4-digit)
The allowable values are 1901 to 2155, and 0000 in the 4 year format and 1970-2069 if you use the 2 digit format (70-69). MySQL displays YEAR values in YYYY format, but allows you to assign values to YEAR columns using either strings or numbers. (The YEAR type is new in MySQL 3.22.)
CHAR
Use for : A fixed-length string that is always right-padded with spaces to the specified length when stored
The range of Length is 1 to 255 characters. Trailing spaces are removed when the value is retrieved. CHAR values are sorted and compared in case-insensitive fashion according to the default character set unless the BINARY keyword is given
VARCHAR
Use for : A variable-length string. Note: Trailing spaces are removed when the value is stored (this differs from the ANSI SQL specification)
The range of Length is 1 to 255 characters. VARCHAR values are sorted and compared in case-insensitive fashion unless the BINARY keyword is given
TINYBLOB, TINYTEXT
A BLOB or TEXT column with a maximum length of 255 (2^8 – 1) characters
BLOB, TEXT
A BLOB or TEXT column with a maximum length of 65535 (2^16 – 1) characters
MEDIUMBLOB, MEDIUMTEXT
A BLOB or TEXT column with a maximum length of 16777215 (2^24 – 1) characters
LONGBLOB, LONGTEXT
A BLOB or TEXT column with a maximum length of 4294967295 (2^32 – 1) characters
ENUM
Use for : An enumeration
A string object that can have only one value, chosen from the list of values ‘value1’, ‘value2’, …, or NULL. An ENUM can have a maximum of 65535 distinct values.
SET
Use for : A set
A string object that can have zero or more values, each of which must be chosen from the list of values ‘value1’, ‘value2’, … A SET can have a maximum of 64 members
