Using Data Types from Other Database Engines
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To facilitate the use of code written for SQL implementations from other vendors, MySQL maps data
types as shown in the following table. These mappings make it easier to import table definitions from
other database systems into MySQL.
Other Vendor Type
MySQL Type
BOOL
TINYINT
BOOLEAN
TINYINT
CHARACTER VARYING(M)
VARCHAR(M)
FIXED
DECIMAL
FLOAT4
FLOAT
FLOAT8
DOUBLE
INT1
TINYINT
INT2
SMALLINT
INT3
MEDIUMINT
INT4
INT
INT8
BIGINT
LONG VARBINARY
MEDIUMBLOB
LONG VARCHAR
MEDIUMTEXT
LONG
MEDIUMTEXT
MIDDLEINT
MEDIUMINT
NUMERIC
DECIMAL
Data type mapping occurs at table creation time, after which the original type specifications are
discarded. If you create a table with types used by other vendors and then issue a
DESCRIBE
tbl_name
statement, MySQL reports the table structure using the equivalent MySQL types. For
example:
mysql>
CREATE TABLE t (a BOOL, b FLOAT8, c LONG VARCHAR, d NUMERIC);
Query OK, 0 rows affected (0.00 sec)
mysql>
DESCRIBE t;
+-------+---------------+------+-----+---------+-------+
| Field | Type | Null | Key | Default | Extra |
+-------+---------------+------+-----+---------+-------+
| a | tinyint(1) | YES | | NULL | |
| b | double | YES | | NULL | |
| c | mediumtext | YES | | NULL | |
| d | decimal(10,0) | YES | | NULL | |
+-------+---------------+------+-----+---------+-------+
4 rows in set (0.01 sec)
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