Help Center/ GaussDB/ Service Overview/ Compatibility with MySQL Databases/ Centralized Instances/ MySQL Compatibility in M-Compatible Mode/ Data Types
Updated on 2024-11-11 GMT+08:00
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Data Types

The data types of GaussDB are the same as those of MySQL in most function scenarios, but there are some differences.

  • Unless otherwise specified, the precision, scale, and number of bits of some data types cannot be defined as floating-point values. You are advised to use valid integer values.
  • The command output of GaussDB ends with \0. MySQL displays the entire character string. Therefore, GaussDB truncates the bytes after \0, but MySQL does not.

    Example:

    -- GaussDB
m_db=# SELECT FORMAT(1000, 4, 'bg_BG');
 format 
--------
 1
(1 row)
m_db=# SELECT CONCAT('123', b'00000000', 'aa');
 concat 
--------
 123
(1 row)

-- MySQL
mysql> SELECT FORMAT(1000, 4, 'bg_BG');
+--------------------------+
| FORMAT(1000, 4, 'bg_BG') |
+--------------------------+
| 1 000,0000               |
+--------------------------+
1 row in set (0.01 sec)
mysql> SELECT CONCAT('123', b'00000000', 'aa');
+----------------------------------+
| CONCAT('123', b'00000000', 'aa') |
+----------------------------------+
| 123 aa                           |
+----------------------------------+
1 row in set (0.00 sec)