About Data Definition Language (DDL) Statements

The statements that create, change, and drop schema objects are data definition language (DDL) statements. Before and after a DDL statement, Oracle Database issues an implicit COMMIT statement; therefore, you cannot roll back a DDL statement.

In the SQL*Plus environment, you can enter a DDL statement after the SQL> prompt.

In the SQL Developer environment, you can enter a DDL statement in the SQL Worksheet. Alternatively, you can use SQL Developer tools to create, change, and drop objects.

Some DDL statements that create schema objects have an optional OR REPLACE clause, which allows a statement to replace an existing schema object with another that has the same name and type. When SQL Developer generates code for one of these statements, it always includes the OR REPLACE clause.

To see the effect of a DDL statement in SQL Developer, you might have to click the Refresh icon.