How to remove unique key from mysql table

Question

I need to remove a unique key from my mysql table  How can remove that using mysql query   I tried this but it is not working  alter table tbl quiz attempt master drop unique key    Please help me  Thanks

User · Answer

First you need to know the exact name of the INDEX (Unique key in this case) to delete or update it.
INDEX names are usually same as column names. In case of more than one INDEX applied on a column, MySQL automatically suffixes numbering to the column names to create unique INDEX names.

For example if 2 indexes are applied on a column named customer_id

The first index will be named as customer_id itself.
The second index will be names as customer_id_2 and so on.

To know the name of the index you want to delete or update

SHOW INDEX FROM <table_name>

as suggested by @Amr

To delete an index

ALTER TABLE <table_name> DROP INDEX <index_name>;

User · Answer

All keys are named  you should use something like this -  ALTER TABLE tbl quiz attempt master   DROP INDEX index name    To drop primary key use this one -  ALTER TABLE tbl quiz attempt master   DROP INDEX  PRIMARY     ALTER TABLE Syntax

User · Answer

ALTER TABLE mytable DROP INDEX key Name

User · Answer

For those who don t know how to get index name which mentioned in Devart s answer  or key name which mentioned in Uday Sawant s answer  you can get it like this    SHOW INDEX FROM table name    This will show all indexes for the given table  then you can pick name of the index or unique key that you want to remove

User · Answer

There are two method two remove index in mysql  First method is GUI  In this method you have to open GUI interface of MYSQL and then go to that database and then go to that particular table in which you want to remove index   After that click on the structure option  Then you can see table structure and below you can see table indexes  You can remove indexes by clicking on drop option    Second method by   ALTER TABLE student login credentials DROP INDEX created at    here student login credentials is table name and created at is column name

User · Answer

Unique key is actually an index   http   codeghar wordpress com 2008 03 28 drop-unique-constraint-in-mysql

User · Answer

To add a unique key use    alter table your table add UNIQUE target column name     To remove a unique key use   alter table your table drop INDEX target column name

[mysql] How to remove unique key from mysql table

To know the name of the index you want to delete or update

To delete an index

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