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Returning a Value Even If There Is No Result in a MySQL Query
You can use IFNULL() function from MySQL to return a value even if there is not result. Let us create a table. Te query to create a table.
mysql> create table IfNullDemo −> ( −> Id int, −> Name varchar(100) −> ); Query OK, 0 rows affected (0.60 sec)
Insert some records in the table with the help of insert command. The query is as follows −
mysql> insert into IfNullDemo values(1,'John'); Query OK, 1 row affected (0.18 sec) mysql> insert into IfNullDemo values(200,'Sam'); Query OK, 1 row affected (0.21 sec) mysql> insert into IfNullDemo values(204,'Carol'); Query OK, 1 row affected (0.14 sec) mysql> insert into IfNullDemo values(510,'Johnson'); Query OK, 1 row affected (0.18 sec)
Display all records from the table with the help of select statement. The query is as follows −
mysql> select *from IfNullDemo;
The following is the output −
+------+---------+ | Id | Name | +------+---------+ | 1 | John | | 200 | Sam | | 204 | Carol | | 510 | Johnson | +------+---------+ 4 rows in set (0.00 sec)
Let us first return a value for TRUE condition −
The query is as follows −
mysql> select ifnull((select Id from IfNullDemo where Id = 200),'No Result Found') As ResultFound;
The following is the output −
+-------------+ | ResultFound | +-------------+ | 200 | +-------------+ 1 row in set (0.00 sec)
Now, let us return a value if there is no result using the IFNULL method. The query is as follows −
mysql> select ifnull((select Id from IfNullDemo where Id = 400),'No Result Found') As ResultFound;
The following is the output −
+-----------------+ | ResultFound | +-----------------+ | No Result Found | +-----------------+ 1 row in set (0.00 sec)
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