mysql> alter table [table name] change [old column name] [new column name] varchar (50);

mysql> alter table [table name] add unique ([column name]);

To change the column name and make it unique in MySQL, you can use the ALTER TABLE statement. Assuming you want to change the column name from old_column to new_column and make it unique, you can execute the following SQL command:

sql

ALTER TABLE your_table

CHANGE COLUMN old_column new_column datatype UNIQUE;

Replace your_table with the name of your table, old_column with the current column name, new_column with the desired column name, and datatype with the data type of the column. The UNIQUE constraint ensures that all values in the column are unique, preventing duplicates.

For example, if you have a table named my_table, and you want to change the column name from name to unique_name and make it unique, and assuming it’s a VARCHAR column, you can execute:

sql

ALTER TABLE my_table

CHANGE COLUMN name unique_name VARCHAR(255) UNIQUE;

This command will rename the column name to unique_name and ensure that all values in the column are unique.