PHP and MySQL Web Development 4th Ed-tqw-_darksiderg

Choosing Column Data Types
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For integer types, you can also specify whether you want them to be UNSIGNED,as
shown in Listing 9.1.
For all numeric types, you can also specify the ZEROFILL attribute.When values from
a ZEROFILL column are displayed, they are padded with leading zeros. If you specify a
column as ZEROFILL, it will automatically also be UNSIGNED.
The integral types are shown in Table 9.5. Note that the ranges listed in this table
show the signed range on one line and the unsigned range on the next.
Table 9.5 Integral Data Types
Type Range Storage Description
(Bytes)
TINYINT[(M)] –127..128 1 Very small integers
or 0..255
BIT
Synonym for TINYINT
BOOL
Synonym for TINYINT
SMALLINT[(M)] –32768..32767 2 Small integers
or 0..65535
MEDIUMINT[(M)] –8388608.. 3 Medium-sized integers
8388607
or 0..16777215
INT[(M)] –2 31 ..2 31 –1 4 Regular integers
or 0..2 32 –1
INTEGER[(M)]
Synonym for INT
BIGINT[(M)] –2 63 ..2 63 –1 8 Big integers
or 0..2 64 –1
The floating-point types are shown in Table 9.6.
Table 9.6 Floating-Point Data Types
Type Range Storage Description
(bytes)
FLOAT(precision) Depends on Varies Can be used to specify
precision
single or double precision
floating-point numbers.
FLOAT[(M,D)] ±1.175494351E-38 4 Single precision floating-
±3.402823466E+38
point number.These
numbers are equivalent to
FLOAT(4) but with a
specified display width
and number of decimal
places.