==== Identity Columns ====

Force use of identity, generate error if statement references identity column
<code>CREATE TABLE test_table (
  id          NUMBER GENERATED ALWAYS AS IDENTITY,
  description VARCHAR2(40)
);</code>

If statement references identity column then use that value.\\
Use the identity value if the column isn't referenced.\\
Cannot use null value.
<code>CREATE TABLE test_table (
  id          NUMBER GENERATED BY DEFAULT AS IDENTITY,
  description VARCHAR2(40)
);</code>

If statement references identity column then use that value. \\
Use the identity value if the column isn't referenced. \\
Can use a null value.
<code>CREATE TABLE test_table (
  id          NUMBER GENERATED BY DEFAULT ON NULL AS IDENTITY,
  description VARCHAR2(40)
);</code>

Start the identity number with 100 and increment each value by 10
<code>CREATE TABLE test_table (
  id          NUMBER GENERATED BY DEFAULT ON NULL AS IDENTITY (START WITH 100 INCREMENT BY 10),
  description VARCHAR2(30)
);</code>