MySQL add “prefix” to every column?

MySQLMySQLi Database

To create a view only if it does not already exist, you can use the following syntax −

CREATE OR REPLACE VIEW yourViewName AS SELECT *FROM yourTableName;

To understand the above syntax, let us create a table. 

The query to create a table is as follows −

mysql> create table createViewDemo
   -> (
   -> Id int NOT NULL AUTO_INCREMENT PRIMARY KEY,
   -> Name varchar(20)
   -> );
Query OK, 0 rows affected (0.58 sec)

Insert some records in the table using insert command. 

The query is as follows −

mysql> insert into createViewDemo(Name) values('John');
Query OK, 1 row affected (0.22 sec)
mysql> insert into createViewDemo(Name) values('Carol');
Query OK, 1 row affected (0.15 sec)
mysql> insert into createViewDemo(Name) values('Bob');
Query OK, 1 row affected (0.15 sec)
mysql> insert into createViewDemo(Name) values('Sam');
Query OK, 1 row affected (0.14 sec)

Display all records from the table using select statement. 

The query is as follows −

mysql> select *from createViewDemo;

Here is the output −

+----+-------+
| Id | Name  |
+----+-------+
| 1  | John  |
| 2  | Carol |
| 3  | Bob   |
| 4  | Sam   |
+----+-------+
4 rows in set (0.00 sec)

Here is the query to create a view only if it does not already exist −

mysql> CREATE OR REPLACE VIEW New_ViewDemo AS select *from createViewDemo;
Query OK, 0 rows affected (0.13 sec)

Let us check the records of view. 

The query is as follows −

mysql> select *from New_ViewDemo;

The following is The output −

+----+-------+
| Id | Name  |
+----+-------+
| 1  | John  |
| 2  | Carol |
| 3  | Bob   |
| 4  | Sam   |
+----+-------+
4 rows in set (0.02 sec)
raja
Published on 01-Apr-2019 07:00:20
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