What methods of modifying database tables do you know?

SQL Data Definition Language (DDL) commands are typically used to modify database tables. Main methods include:

• ALTER TABLE — allows changing the structure of a table: adding, removing, or modifying columns, changing data types, adding or removing constraints.

• CREATE TABLE — creating a new table.

• DROP TABLE — deleting a table.

• RENAME TABLE — renaming a table (in some DBMS).

Example of adding a column:

ALTER TABLE employees ADD COLUMN birthdate DATE;

Example of changing a column's data type:

ALTER TABLE employees ALTER COLUMN salary TYPE DECIMAL(10,2);

In Java, such operations are usually performed using JDBC, by sending the corresponding SQL queries to the database.