How does the MySQL SUM() function evaluate whether it gets a column with character data type as its argument?

The MySQL SUM() function will return 0 instead of NULL and issue a warning when getting a character type column as its argument. The following example will be illustrated using data from a table named "Social" -

Example

mysql> Select * from Social;

+------+-------+
| Id   | Name  |
+------+-------+
| 100  | Rahul |
+------+-------+

1 row in set (0.00 sec)

mysql> Select SUM(Name) From Social;

+-----------+
| SUM(Name) |
+-----------+
| 0         |
+-----------+

1 row in set, 1 warning (0.00 sec)

The above is the detailed content of How does the MySQL SUM() function evaluate whether it gets a column with character data type as its argument?. For more information, please follow other related articles on the PHP Chinese website!