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MySQL query to replace null value with empty string in several columns while fetching data
For this, you can use IFNULL() or COALESCE(). Let us first create a table −
mysql> create table DemoTable1849 ( ClientFirstName varchar(20), ClientLastName varchar(20) ); Query OK, 0 rows affected (0.00 sec)
Insert some records in the table using insert command −
mysql> insert into DemoTable1849 values('John',NULL);
Query OK, 1 row affected (0.00 sec)
mysql> insert into DemoTable1849 values(NULL,'Miller');
Query OK, 1 row affected (0.00 sec)
mysql> insert into DemoTable1849 values(NULL,NULL);
Query OK, 1 row affected (0.00 sec)
mysql> insert into DemoTable1849 values('Chris','Brown');
Query OK, 1 row affected (0.00 sec)Display all records from the table using select statement −
mysql> select * from DemoTable1849;
This will produce the following output −
+-----------------+----------------+ | ClientFirstName | ClientLastName | +-----------------+----------------+ | John | NULL | | NULL | Miller | | NULL | NULL | | Chris | Brown | +-----------------+----------------+ 4 rows in set (0.00 sec)
Here is the query to replace null value with empty string in several columns while fetching data −
mysql> select ifnull(ClientFirstName,'') as ClientFirstName,ifnull(ClientLastName,'') as ClientLastName from DemoTable1849;
This will produce the following output −
+-----------------+----------------+ | ClientFirstName | ClientLastName | +-----------------+----------------+ | John | | | | Miller | | | | | Chris | Brown | +-----------------+----------------+ 4 rows in set (0.00 sec)
Updated on: 26-Dec-2019
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