Check if a value exists in a column in a MySQL table?

Let us first create a table −

mysql> create table DemoTable807(
   ClientId int NOT NULL AUTO_INCREMENT PRIMARY KEY,
   ClientName varchar(100),
   ClientCountryName varchar(100)
);
Query OK, 0 rows affected (0.64 sec)  

Insert some records in the table using insert command −

mysql> insert into DemoTable807(ClientName,ClientCountryName) values('Chris','UK');
Query OK, 1 row affected (0.20 sec)
mysql> insert into DemoTable807(ClientName,ClientCountryName) values('David','AUS');
Query OK, 1 row affected (0.15 sec)
mysql> insert into DemoTable807(ClientName,ClientCountryName) values('Robert','US');
Query OK, 1 row affected (0.74 sec)
mysql> insert into DemoTable807(ClientName,ClientCountryName) values('Mike','ENG');
Query OK, 1 row affected (0.14 sec)

Display all records from the table using select statement −

mysql> select *from DemoTable807;

This will produce the following output −

+----------+------------+-------------------+
| ClientId | ClientName | ClientCountryName |
+----------+------------+-------------------+
|        1 | Chris      | UK                |
|        2 | David      | AUS               |
|        3 | Robert     | US                |
|        4 | Mike       | ENG               |
+----------+------------+-------------------+
4 rows in set (0.00 sec)

Following is the query to check if a value exists in a column in a MySQL table −

mysql> select *from DemoTable807 where ClientCountryName='US';

This will produce the following output −

+----------+------------+-------------------+
| ClientId | ClientName | ClientCountryName |
+----------+------------+-------------------+
|        3 | Robert     | US                |
+----------+------------+-------------------+
1 row in set (0.00 sec)