Use of the "Oracle" sequence sequence object

************************************************************************* * * * Original:blog.csdn.net/clark_xu Xu Changliang's Column************************************************************************

Sequence:Oracle can generate primary keys by sequence

1. Create a sequence

CREATE TABLE Foo (

foo_id Number (11),

Foo_value VARCHAR2 (50),

Constraint FOO_PK primary KEY (FOO_ID)

)

Creating a sequence DDL

Create sequence sequence name

[Start with value (10000)]

[Increment by value ]

Delete sequence DDL

drop sequence sequence name

2. View the sequence

Get the current sequence value by pseudo-column currval

To take the next value of a sequence value by pseudo-column nextval

Select Seq_foo.nextval from dual;

Select Seq_foo.currval from dual;

3. Using sequences as primary keys

INSERT into foo (foo_id,foo_value) VALUES (Seq.foo.nextval, ' Clark ');

Use of the "Oracle" sequence sequence object