Rename MySQL Column with ALTER TABLE Command
ALTER TABLE is an essential command used to change the structure of a MySQL table. You can use it to add or delete columns, change the type of data within the columns, and even rename entire databases. The function that concerns us the most is how to utilize ALTER TABLE to rename a column.
Clauses give us additional control over the renaming process. The RENAME COLUMN and CHANGE clause both allow for the names of existing columns to be altered. The difference is that the CHANGE clause can also be used to alter the data types of a column. The commands are straightforward, and you may use the clause that fits your requirements best.
How to Use the RENAME COLUMN Clause (MySQL 8.0)
The simplest way to rename a column is to use the ALTER TABLE command with the RENAME COLUMN clause. This clause is available since MySQL version 8.0.
Let’s illustrate its simple syntax. To change a column name, enter the following statement in your MySQL shell:
ALTER TABLE your_table_name RENAME COLUMN original_column_name TO new_column_name;
Exchange the your_table_name, original_column_name, and new_column_name with your table and column names. Keep in mind that you cannot rename a column to a name that already exists in the table.
Note: The word COLUMN is obligatory for the ALTER TABLE RENAME COLUMN command. ALTER TABLE RENAME is the existing syntax to rename the entire table.
The RENAME COLUMN clause can only be used to rename a column. If you need additional functions, such as changing the data definition, or position of a column, you need to use the CHANGE clause instead.
Rename MySQL Column with CHANGE Clause
The CHANGE clause offers important additions to the renaming process. It can be used to rename a column and change the data type of that column with the same command.
Enter the following command in your MySQL client shell to change the name of the column and its definition:
ALTER TABLE your_table_name CHANGE original_column_name new_col_name data_type;
The data_type element is mandatory, even if you want to keep the existing datatype.
Use additional options to further manipulate table columns. The CHANGE also allows you to place the column in a different position in the table by using the optional FIRST | AFTER column_name clause. For example:
ALTER TABLE your_table_name CHANGE original_column_name new_col_name y_data_type AFTER column_x;
You have successfully changed the name of the column, changed the data type to y_data_type, and positioned the column after column_x.