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(5));
+-------------------+
| 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.
Converting a DATETIME type value to CHAR may fail in some cases (CONVERT(NOW(), CHAR) works but CONVERT(a_datetime_column, CHAR) may not).