Int16, 等于short, 占2个字节. -32768 32767
Int32, 等于int, 占4个字节. -2147483648 2147483647
Int64, 等于long, 占8个字节. -9223372036854775808 9223372036854775807
Byte, 它等于byte, 0 - 255.
https://dev.mysql.com/doc/refman/5.7/en/integer-types.html