MySQL中各数据类型的取值范围

TINYINT                                                             -128 - 127

TINYINT UNSIGNED                                           0 - 255

SMALLINT                                                          -32768 - 32767

SMALLINT UNSIGNED                                        0 - 65535

MEDIUMINT                                                      -8388608 - 8388607

MEDIUMINT UNSIGNED                                     0 - 16777215

INT 或 INTEGER                                                  -2147483648 - 2147483647

INT UNSIGNED 或 INTEGER UNSIGNED                - 4294967295

BIGINT                                                               -9223372036854775808 - 9223372036854775807

BIGINT UNSIGNED                                             0 - 18446744073709551615

FLOAT                                        -3.402823466E+38 - -1.175494351E-38,0,1.175494351E-38 - 3.402823466E+38

DOUBLE 或 DOUBLE PRECISION 或 REAL     -1.7976931348623157E+308 - -2.2250738585072014E-308,0,2.2250738585072014E-308 - 1.7976931348623157E+308

DECIMAL[(M,[D])] 或 NUMERIC(M,D)           由M(整个数字的长度,包括小数点,小数点左边的位数,小数点右边的位数,但不包括负号)和D(小数点右边的位数)来决定,M缺省为10,D缺省为0

DATE                               1000-01-01 - 9999-12-31

DATETIME                        1000-01-01 00:00:00 - 9999-12-31 23:59:59

TIMESTAMP                     1970-01-01 00:00:00 - 2037年的某天(具体是哪天我也不知道,呵呵)

TIME                               -838:59:59' to 838:59:59

YEAR[(2|4)]                       缺省为4位格式,4位格式取值范围为1901 - 2155,0000,2位格式取值范围为70-69(1970-2069)

CHAR(M) [BINARY] 或 NCHAR(M) [BINARY]                             M的范围为1 - 255,如果没有BINARY项,则不分大小写,NCHAR表示使用缺省的字符集.在数据库中以空格补足,但在取出来时末尾的空格将自动去掉.

[NATIONAL] VARCHAR(M) [BINARY]                      M的范围为1 - 255.在数据库中末尾的空格将自动去掉.

TINYBLOB 或 TINYTEXT                                         255(2^8-1)个字符

BLOB 或 TEXT                                                       65535(2^16-1)个字符

MEDIUMBLOB 或 MEDIUMTEXT                            16777215 (2^24-1)个字符

LONGBLOB 或 LONGTEXT                                     4294967295 (2^32-1)个字符

ENUM('value1','value2',...)                                      可以总共有65535个不同的值
 
SET('value1','value2',...)                                           多有64个成员