Learning Mysql

Other string types
The remaining types in MySQL are variants of the string type here’s a list that you can choose from—excepting CHAR, which was described in Common column types”:
VARCHAR(width)
A commonly used string type. Stores variable-length strings (such as names, addresses, or cities) up to a maximum
width
. The maximum value of
width
is 65,535
characters.
Prior to MySQL version 5.0.3, the maximum length was 255 characters. Trying to specify a longer length would cause an error inversions up to 4.1.0. Between versions and 5.0.3, the server would silently change the column type to the smallest
TEXT
type that would hold values of that length
A
VARCHAR
type incurs one or two extra bytes of overhead to store the length of the string, depending on whether the string is shorter than or longer than 255
characters.
Trailing spaces are removed when a value is stored you can use
TEXT
or
BLOB
types to avoid this behavior.
BINARY(width) and
VARBINARY(width)
Available since MySQL 4.1.2, these are equivalent to
CHAR
and
VARCHAR
but allow you to store binary strings. Binary strings have no character set, and sorting them is case-sensitive. Read the descriptions of
CHAR
and
VARCHAR
for other details. If you’re using a MySQL version earlier than 4.1.2, you can create the same behavior by adding the keyword
BINARY
after the
CHAR
or
VARCHAR
declaration, as in
CHAR(12)
BINARY
BLOB
The commonly used type for storing large data. Stores a variable amount of data
(such as an image, video, or other nontext file) up to 65,535 bytes in length. The data is treated as binary—that is, no character set is assumed, and comparisons and sorts are case-sensitive. There is no trailing-space-removal behavior as for the
CHAR
or
VARCHAR
types. In addition, a
DEFAULT
clause is not permitted, and you must take a prefix of the value when using it in an index (this is discussed in the next section).
TEXT
A commonly used type for storing large string data objects. Stores a variable amount of data (such as a document or other text file) up to 65,535 bytes in length.
It is identical to BLOB, except that the data is treated as belonging to a character set.
Since MySQL 4.1, the character set can beset for each column, and prior to that the character set of the server was assumed. Comparisons and sorts are case-in-
sensitive.
TINYBLOB
and
TINYTEXT
Identical to
BLOB
and TEXT, respectively, except that a maximum of 255 bytes can be stored.

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