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How to check if a column exist in a MySQL table?
To understand whether a column exist or not, we have the following approaches −
- With the help of DESC command
- Using SHOW command
Firstly, we will create a table with columns −
mysql> CREATE table ColumnExistDemo -> ( -> UniqueId int, -> UniqueName varchar(200), -> UniqueAddress varchar(200) -> ); Query OK, 0 rows affected (0.57 sec)
In the first approach, we will get the entire column name with meaningful information. The syntax is as follows −
DESC yourTableName;
Let us apply the above query to check whether the column name exists or not. However, this approach is not good since it display all the columns.
mysql> DESC ColumnExistDemo;
The following is the output
+---------------+--------------+------+-----+---------+-------+ | Field | Type | Null | Key | Default | Extra | +---------------+--------------+------+-----+---------+-------+ | UniqueId | int(11) | YES | | NULL | | | UniqueName | varchar(200) | YES | | NULL | | | UniqueAddress | varchar(200) | YES | | NULL | | +---------------+--------------+------+-----+---------+-------+ 3 rows in set (0.01 sec)
The second approach is better, since we can check for a single column. The syntax is as follows −
SHOW COLUMNS from `yourTableName` LIKE 'yourColumnName';
Now, I am applying the above query to check whether colum exist or not. The query is as follows −
mysql> SHOW COLUMNS from `ColumnExistDemo` LIKE 'UniqueName';
The following is the output
+------------+--------------+------+-----+---------+-------+ | Field | Type | Null | Key | Default | Extra | +------------+--------------+------+-----+---------+-------+ | UniqueName | varchar(200) | YES | | NULL | | +------------+--------------+------+-----+---------+-------+ 1 row in set (0.00 sec)
Updated on: 25-Jun-2020
4K+ Views
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