CONVERT
Description
The CONVERT()
function converts a value into the specified datatype or character set.
Syntax
> CONVERT(value, type)
Or:
> CONVERT(value USING charset)
Parameter Values
Parameter | Description |
---|---|
value | Required. The value to convert. |
datatype | Required. The datatype to convert to. |
charset | Required. The character set to convert to. |
Currently, convert
can support following conversion:
- Conversion between numeric types, mainly including SIGNED, UNSIGNED, FLOAT, and DOUBLE type.
- Numeric types to character CHAR type.
- Numeric character types to numerical types(negative into SIGNED).
Examples
mysql> select convert(150,char);
+-------------------+
| cast(150 as char) |
+-------------------+
| 150 |
+-------------------+
1 row in set (0.01 sec)
CREATE TABLE t1(a tinyint);
INSERT INTO t1 VALUES (127);
mysql> SELECT 1 FROM
-> (SELECT CONVERT(t2.a USING UTF8) FROM t1, t1 t2 LIMIT 1) AS s LIMIT 1;
+------+
| 1 |
+------+
| 1 |
+------+
1 row in set (0.00 sec)
Constraints
- Non-numeric character types cannot be converted to numeric types.
- Numeric and character types with formats of Data cannot be converted to Date.
- Date and Datetime types cannot be converted to character types.
- Date and Datetime cannot be converted to each other.