What is the usage of “change” in MySQL?

In MySQL, the CHANGE keyword is used to modify columns or indexes in a table.

Grammar: Syntax

ALTER TABLE table_name
CHANGE column_name new_column_name column_definition;

In this case, table_name is the name of the table to be modified, column_name is the name of the column to be changed, new_column_name is the new name to be changed to, and column_definition is the definition of the new column.

For example, to change the column name “old_col” to “new_col” in the table.

ALTER TABLE my_table
CHANGE old_col new_col VARCHAR(50);

Furthermore, CHANGE can also be used to modify the index name in the table. The syntax is as follows:

ALTER TABLE table_name
CHANGE INDEX old_index_name new_index_name;

In this case, table_name refers to the name of the table to be modified, old_index_name is the name of the index to be modified, and new_index_name is the new name to be changed to.

For example, to change the index name in the table from “old_index” to “new_index”:

ALTER TABLE my_table
CHANGE INDEX old_index new_index;