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Need help selecting non-empty column values from MySQL?
Select non-empty column values using NOT IS NULL and TRIM() function. The syntax is as follows.
SELECT * FROM yourTableName WHERE yourColumnName IS NOT NULL AND TRIM(yourColumnName) <> ' ';
You can select non-empty value as well as whitespace from column using the same TRIM() function.
To understand the syntax we discussed above, let us create a table. The query to create a table is as follows −
mysql> create table SelectNonEmptyValues -> ( -> Id int not null auto_increment, -> Name varchar(30), -> PRIMARY KEY(Id) -> ); Query OK, 0 rows affected (0.62 sec)
Insert records in the table using insert command. The query is as follows −
mysql> insert into SelectNonEmptyValues(Name) values('John Smith');
Query OK, 1 row affected (0.20 sec)
mysql> insert into SelectNonEmptyValues(Name) values(NULL);
Query OK, 1 row affected (0.13 sec)
mysql> insert into SelectNonEmptyValues(Name) values('');
Query OK, 1 row affected (0.24 sec)
mysql> insert into SelectNonEmptyValues(Name) values('Carol Taylor');
Query OK, 1 row affected (0.13 sec)
mysql> insert into SelectNonEmptyValues(Name) values('DavidMiller');
Query OK, 1 row affected (0.28 sec)
mysql> insert into SelectNonEmptyValues(Name) values(' ');
Query OK, 1 row affected (0.18 sec)Display all records from the table using select statement −
mysql> select *from SelectNonEmptyValues;
The following is the output −
+----+-----------------------+ | Id | Name | +----+-----------------------+ | 1 | John Smith | | 2 | NULL | | 3 | | | 4 | Carol Taylor | | 5 | DavidMiller | | 6 | | +----+-----------------------+ 6 rows in set (0.00 sec)
Here is the query to select non-empty values. The below query works for all cases − if the column has NULL, empty string or whitespaces −
mysql> SELECT * FROM SelectNonEmptyValues WHERE Name IS NOT NULL AND TRIM(Name) <> '';
The following is the output −
+----+--------------+ | Id | Name | +----+--------------+ | 1 | John Smith | | 4 | Carol Taylor | | 5 | DavidMiller | +----+--------------+ 3 rows in set (0.00 sec)
Updated on: 30-Jul-2019
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