Implement Dynamic SQL query inside a MySQL stored procedure?
For dynamic SQL query in a stored procedure, use the concept of PREPARE STATEMENT. Let us first create a table −
mysql> create table DemoTable2033
-> (
-> Id int NOT NULL AUTO_INCREMENT PRIMARY KEY,
-> Name varchar(20)
-> );
Query OK, 0 rows affected (1.61 sec)
Insert some records in the table using insert command −
mysql> insert into DemoTable2033(Name) values('Chris');
Query OK, 1 row affected (0.85 sec)
mysql> insert into DemoTable2033(Name) values('Bob');
Query OK, 1 row affected (0.19 sec)
mysql> insert into DemoTable2033(Name) values('David');
Query OK, 1 row affected (0.24 sec)
mysql> insert into DemoTable2033(Name) values('Mike');
Query OK, 1 row affected (0.12 sec)Display all records from the table using select statement −
mysql> select *from DemoTable2033;
This will produce the following output −
+----+-------+
| Id | Name |
+----+-------+
| 1 | Chris |
| 2 | Bob |
| 3 | David |
| 4 | Mike |
+----+-------+
4 rows in set (0.00 sec)
Following is the query to create a stored procedure and implement dynamic SQL −
mysql> delimiter //
mysql> create procedure dynamic_query()
-> begin
-> set @query=concat("select *from DemoTable2033 where Id=3");
-> prepare st from @query;
-> execute st;
-> end
-> //
Query OK, 0 rows affected (0.13 sec)
mysql> delimiter ;Call the stored procedure −
mysql> call dynamic_query();
This will produce the following output −
+----+-------+
| Id | Name |
+----+-------+
| 3 | David |
+----+-------+
1 row in set (0.04 sec)
Query OK, 0 rows affected (0.05 sec)
Published on 07-Apr-2020 14:59:48
