Change Oracle Table Column Data Type

To change the data type of a table’s field, you can use the ALTER TABLE statement. The specific steps are as follows:

1. To begin, use the DESCRIBE command or query metadata tables (such as USER_TAB_COLUMNS) to view the current table’s structure and field types.
2. The ALTER TABLE statement is used to modify the structure of a table. For instance, if you want to change the data type of the “column_name” field from VARCHAR2 to NUMBER, you can use the following statement:

ALTER TABLE table_name MODIFY column_name NUMBER;

1. Confirm that the changes have taken effect, you can verify the field type modification by using the DESCRIBE command or querying the metadata table again.

It is important to note that changing field types may result in data loss or formatting issues. It is recommended to back up data or conduct thorough testing before making any modifications.