Sequence

-

Generate Unique Sequential values

    Sequence has 2 pseudocolumns

    1. CURRVAL

    2. NEXTVAL


CURRVAL :  gives the most recently generated value

NEXTVAL : gives the next available value in the sequence to generate

sequence will start generating value from its MINVALUE

Default MINVALUE is 1

default incremental value of sequence is +1

Same sequence can be used in multiple tables but not suggestable. One sequence for one table.

Comments

Post a Comment

Popular posts from this blog

Stored Procedure

-
1. When we have to same task everyday then instead of writing queries we can save the query in procedure and then just run it when required. 2. Named PLSQL program 3. Permanently saved in DB Features :  1. Procedures executed explicitly. Execute Command               Exec Procedurename (arg1, arg2...); 2. Procedures can also executed  implicitly. Using procedured calling statement          Procedurename(arg1, arge2...); 3. Saved in a DB as pre compiled obbject. Complied once only when there is changes in logic of SP then again it will complied. Can call procedure from other proc, func, programs. 4. Procedure can be static or dynamic mean proc may or maynot take arguments. 5. By default proc should not return any value. Types of Proc:  1. Static : Not having arg 2. Dynamic : With arg Syntax : Create or replace procedure procedure_name( arguments ..) is/as  ----------any keyword use declaration  -----declare variables Begin execution statements.... end;
Read more