VARCHAR

SYNONYMS

The following are synonyms for VARCHAR:

• CHAR VARYING

• CHARACTER VARYING

• VARCHAR2

• VARCHARACTER

VARCHAR

For our example of VARCHAR we picked a maximum size that avoids overflowing the maximum row size (65535). Keep in mind that a multi-byte character set would need more space in the row than a single-byte character set. We also avoid the auto-conversion of a VARCHAR into a TEXT, MEDIUMTEXT, or LONGTEXT that can happen when STRICT_TRANS_TABLES is not set in the SQL_MODE.

The example:

CREATE TABLE varchar_example (
   description VARCHAR(20),
   example VARCHAR(65511)
) DEFAULT CHARSET=latin1; -- One byte per char makes the examples clearer

INSERT INTO varchar_example VALUES
   ('Normal foo', 'foo'),
   ('Trailing spaces foo', 'foo      '),
   ('NULLed', NULL),
   ('Empty', ''),
   ('Maximum', RPAD('', 65511, 'x'));

SELECT description, LENGTH(example) AS length
   FROM varchar_example;

+---------------------+--------+
| description         | length |
+---------------------+--------+
| Normal foo          |      3 |
| Trailing spaces foo |      9 |
| NULLed              |   NULL |
| Empty               |      0 |
| Maximum             |  65511 |
+---------------------+--------+

Data Too Long

When SQL_MODE is strict (the default) a value is considered "too long" when its length exceeds the size of the data type, and an error is generated.

Example of data too long behavior for VARCHAR:

TRUNCATE varchar_example;

INSERT INTO varchar_example VALUES
   ('Overflow', RPAD('', 65512, 'x'));

ERROR 1406 (22001): Data too long for column 'example' at row 1