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How to check if a table exists in MySQL and create if it does not already exist?
If you try to create a table and the table name already exist then MySQL will give a warning message. Let us verify the concept.
Here, we are creating a table that already exist −
mysql> CREATE TABLE IF NOT EXISTS DemoTable ( CustomerId int, CustomerName varchar(30), CustomerAge int ); Query OK, 0 rows affected, 1 warning (0.05 sec)
The table name DemoTable is already present. Let us check the warning message.
Following is the query −
mysql> show warnings;
This will produce the following output i.e. the warning message −
+-------+------+------------------------------------+ | Level | Code | Message | +-------+------+------------------------------------+ | Note | 1050 | Table 'demotable' already exists | +-------+------+------------------------------------+ 1 row in set (0.00 sec)
Let us change the table name and create a table that does not already exist −
mysql> CREATE TABLE IF NOT EXISTS DemoTable2 ( CustomerId int, CustomerName varchar(20), CustomerAge int ); Query OK, 0 rows affected (0.56 sec)
Table created successfully above since it does not already exist.
Following is the query to insert records in the table using insert command −
mysql> insert into DemoTable2 values(101,'Chris',23); Query OK, 1 row affected (0.17 sec) mysql> insert into DemoTable2 values(102,'Robert',24); Query OK, 1 row affected (0.12 sec)
Following is the query to display records from the table using select command −
mysql> select *from DemoTable2;
This will produce the following output
+------------+--------------+-------------+ | CustomerId | CustomerName | CustomerAge | +------------+--------------+-------------+ | 101 | Chris | 23 | | 102 | Robert | 24 | +------------+--------------+-------------+ 2 rows in set (0.00 sec)
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