For maximum value, use MAX() along with CAST() for conversion. Since we want maximum value from string-numbers beginning with specific characters, use RLIKE. Let us first create a table −
mysql> create table DemoTable1381 -> ( -> DepartmentId varchar(40) -> ); Query OK, 0 rows affected (0.48 sec)
Insert some records in the table using insert command −
mysql> insert into DemoTable1381 values('IT794'); Query OK, 1 row affected (0.19 sec) mysql> insert into DemoTable1381 values('AT1034'); Query OK, 1 row affected (0.52 sec) mysql> insert into DemoTable1381 values('IT967'); Query OK, 1 row affected (0.12 sec) mysql> insert into DemoTable1381 values('IT874'); Query OK, 1 row affected (0.17 sec) mysql> insert into DemoTable1381 values('AT967'); Query OK, 1 row affected (0.09 sec)
Display all records from the table using select statement −
mysql> select * from DemoTable1381;
This will produce the following output −
+--------------+ | DepartmentId | +--------------+ | IT794 | | AT1034 | | IT967 | | IT874 | | AT967 | +--------------+ 5 rows in set (0.00 sec)
Following is the query to get the maximum value from a column with alphanumeric strings beginning with specific characters i.e. “IT” here −
mysql> select max(cast(substr(trim(DepartmentId),3) AS UNSIGNED)) from DemoTable1381 where DepartmentId RLIKE 'IT';
This will produce the following output −
+-----------------------------------------------------+ | max(cast(substr(trim(DepartmentId),3) AS UNSIGNED)) | +-----------------------------------------------------+ | 967 | +-----------------------------------------------------+ 1 row in set (0.10 sec)