What are mysql data types and what they mean for 

 

Numeric Data Types

INT:

This is going to be used normally for whole number.A normal-sized integer that can be signed or unsigned. If signed, the
allowable range is from –2147483648 to 2147483647. If unsigned, the allowable
range is from 0 to 4294967295. We can specify a width of up to 11 digits.

TINYINT:

A small integer that can be signed or unsigned. If signed, the allowable
range is from –128 to 127. If unsigned, the allowable range is from 0 to
255. We use it for a  width of up to 4 digits.
SMALLINT:

A small integer that can be signed or unsigned. If signed, the
allowable range is from –32768 to 32767. If unsigned, the allowable range is
from 0 to 65535.We use it for  a width of up to 5 digits.
MEDIUMINT:

A medium-sized integer that can be signed or unsigned. If signed,
the allowable range is from –8388608 to 8388607. If unsigned, the allowable
range is from 0 to 16777215.We use it for a width of up to 9 digits.
BIGINT:

We use it for   a width of up to 11 digits. A large integer that can be signed or unsigned. If signed, the allowable
range is from –9223372036854775808 to 9223372036854775807. If
unsigned, the allowable range is from 0 to 18446744073709551615.

FLOAT(M,D):

We use it for precision and scientific notation. A floating-point number that cannot be unsigned. You can
define the display length (M) and the number of decimals (D). This is not
required and defaults to 10,2, where 2 is the number of decimals and 10 is the
total number of digits (including decimals). Decimal precision can go to 24
places for a FLOAT.
 DOUBLE(M,D):

Decimal precision can go to 53 places for a DOUBLE. REAL is a synonym
for DOUBLE. A double-precision floating-point number that cannot be
unsigned. We can define the display length (M) and the number of decimals
(D). This is not required and will default to 16,4, where 4 is the number of
decimals.
DECIMAL(M,D):

An unpacked floating-point number that cannot be unsigned.
In unpacked decimals, each decimal corresponds to 1 byte. Defining the display
length (M) and the number of decimals (D) is required. NUMERIC is a synonym
for DECIMAL.