Note: TEXT(tinytext, text, mediumtext and longtext)
and BLOB(tinyblob, blob, mediumblob and longblob) data type cannot have DEFAULT values.
To set other field properties for Text/Memo
and BLOB (Binary Large Object) (not apply to
binary/varbinary type)
Character set (non-binary strings only)
A character set is a set of symbols and encodings. The Character
set drop-down list defines the type of the character set for field.
Collation (non-binary strings only)
A collation is a set of rules for comparing characters in a character
set. The Collation drop-down list defines the type of the collation
for field.
Note: MySQL chooses the column character set
and collation in the following manner:
- If both CHARACTER SET X and COLLATE Y were specified, then character
set X and collation Y are used.
- If CHARACTER SET X was specified without COLLATE, then character set
X and its default collation are used.
- Otherwise, the table character set and collation are used.
Key Length
The edit box will be enabled when Primary Key is set. KEY LENGTH (1 -
255).
Binary (char and varchar only)
As of MySQL 4.1, values in CHAR and VARCHAR fields are sorted and compared
according to the collation of the character set assigned to the field.
Before MySQL 4.1, sorting and comparison are based on the collation of
the server character set; you can declare the field with the BINARY attribute
to cause sorting and comparison to be based on the numeric values of the
bytes in field values. BINARY does not affect how field values are stored
or retrieved.
To set other field properties for Number/Currency
and Floating Point (not apply to
bit type)
Auto Increment (Number/Currency
only)
The AUTO INCREMENT attribute can be used to generate a unique identity for
new rows. To start with the AUTO INCREMENT value other than 1, you can set
that value in Options.
Unsigned
UNSIGNED values can be used when you want to allow only non-negative numbers
in a field and you need a bigger upper numeric range for the field.
As of MySQL 4.0.2, floating-point and fixed-point types also can be UNSIGNED.
Unlike the integer types, the upper range of column values remains the same.
Zerofill
The default padding of spaces is replaced with zeros. For example, for a
field declared as INT(5) ZEROFILL, a value of 4 is retrieved as 00004; for
a field declared as FLOAT(20,10) ZEROFILL, a value of 0.1 is retrieved as
000000000.1000000015.
Note: If you specify ZEROFILL for a numeric type,
MySQL automatically adds the UNSIGNED attribute to the field.
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