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MySQL query to count all the column values from two columns and exclude NULL values in the total count?
Let us first create a table −
mysql> create table DemoTable1975 ( StudentName varchar(20), StudentMarks int ); Query OK, 0 rows affected (0.00 sec)
Insert some records in the table using insert command −
mysql> insert into DemoTable1975 values('John',45); Query OK, 1 row affected (0.00 sec) mysql> insert into DemoTable1975 values('Chris',67); Query OK, 1 row affected (0.00 sec) mysql> insert into DemoTable1975 values('David',59); Query OK, 1 row affected (0.00 sec) mysql> insert into DemoTable1975 values('Bob',NULL); Query OK, 1 row affected (0.00 sec)
Display all records from the table using select statement −
mysql> select * from DemoTable1975;
This will produce the following output −
+-------------+--------------+ | StudentName | StudentMarks | +-------------+--------------+ | John | 45 | | Chris | 67 | | David | 59 | | Bob | NULL | +-------------+--------------+ 4 rows in set (0.00 sec)
Here is the query to count all the column values −
mysql> select count(StudentName)+count(StudentMarks) from DemoTable1975;
This will produce the following output −
+----------------------------------------+ | count(StudentName)+count(StudentMarks) | +----------------------------------------+ | 7 | +----------------------------------------+ 1 row in set (0.00 sec)
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