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Update all the fields in a table with null or non-null values with MySQL
Let us first create a table −
mysql> create table DemoTable -> ( -> Id int, -> Name varchar(20) -> ); Query OK, 0 rows affected (0.58 sec)
Insert some records in the table using insert command −
mysql> insert into DemoTable values(10,NULL); Query OK, 1 row affected (0.32 sec) mysql> insert into DemoTable values(NULL,'David'); Query OK, 1 row affected (0.16 sec) mysql> insert into DemoTable values(NULL,NULL); Query OK, 1 row affected (0.15 sec)
Display all records from the table using select statement −
mysql> select * from DemoTable;
This will produce the following output−
+------+-------+ | Id | Name | +------+-------+ | 10 | NULL | | NULL | David | | NULL | NULL | +------+-------+ 3 rows in set (0.00 sec)
Here is the query to update all the fields in a table with null or non-null values −
mysql> update DemoTable set Name='Robert' where Id IS NULL or Name IS NULL; Query OK, 3 rows affected (0.22 sec) Rows matched: 3 Changed: 3 Warnings: 0
Let us check the table records once again −
mysql> select * from DemoTable;
This will produce the following output −
+------+--------+ | Id | Name | +------+--------+ | 10 | Robert | | NULL | Robert | | NULL | Robert | +------+--------+ 3 rows in set (0.00 sec)
Updated on: 26-Feb-2020
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