Mysql set primary key

ALTER TABLE tableName MODIFY COLUMN id INT; /* First you should drop auto increment */
ALTER TABLE tableName DROP PRIMARY KEY; /* Dop primary key */
ALTER TABLE tableName ADD PRIMARY KEY (new_id); /* Set primary key to the new column */
ALTER TABLE tableName MODIFY COLUMN new_id INT AUTO_INCREMENT; /* Set auto increment to the new primary key */

Mysql drop key

ALTER TABLE tbl_quiz_attempt_master
  DROP INDEX `PRIMARY`;

Source: stackoverflow.com

Similar codes

-1 vote339 views1 answer
How to change the auto increment in existing table mysql
SQL
0 vote302 views1 answer
Create column that already exists mysql
SQL
41 votes419 views6 answers
Alter table add column in SQL Server
SQL
1 vote369 views1 answer
Find size of all DB's postgres
SQL
0 vote325 views1 answer
How to user id to show in from date to upto date in mssql server
SQL
1 vote322 views1 answer
How to use a trigger to validate input data
SQL
0 vote306 views1 answer
Sql query for getting data with join and count
SQL
0 vote335 views1 answer
Postgresql create query
SQL
0 vote352 views1 answer
SqlMessage: "Table 'Friends' already exists",
SQL
2 votes270 views1 answer
Sql group by different columns
SQL