Mysql uses sum() to find the sum of the id field: use "SELECT SUM(id) FROM data table name;" to find the sum of the id field and return the sum of the id field values; SUM() function When calculating, ignore rows with NULL column values.
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The SUM() function returns the total number of numeric columns.
SQL SUM() Syntax
SELECT SUM(column_name) FROM table_name;
How does the SUM() function work?
If you use the SUM function in a SELECT statement that returns no matching rows, the SUM function returns NULL instead of 0.
The DISTINCT operator allows calculation of distinct values in a collection.
The SUM function ignores NULL values in calculations.
[Example] Calculate the sum of the id fields in the tb_text table. The input SQL statement and execution results are as follows.
mysql> SELECT SUM(id)
-> AS sum
-> FROM tb_text;
+-----------+
| sum |
+-----------+
| 942 |
+-----------+
1 row in set (0.00 sec)As you can see from the query results, the sum of the id fields returned by the SUM() function is 942.
Tip: The SUM() function ignores rows with NULL column values when calculating.
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