以下是MySQL中各字段的取值范围：

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

0 - 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