How to create a self-incremental sequence

Create a self-increment sequence in an Oracle database with the following steps: Connect to the database. Create a sequence using the CREATE SEQUENCE syntax, specifying the sequence name, starting value, incremental value, maximum value, and minimum value. Use SELECT query to view the created sequence. Use the NEXTVAL function to get the next value of the sequence.

How to create a self-incremental sequence using Oracle?

Creating a self-incrementing sequence in an Oracle database is very simple, and you can use the following steps:

1. Connect to a database: Use SQL*Plus or other tools to connect to an Oracle database.
2. Create a sequence: Create a sequence using the following syntax:

 <code class="sql">CREATE SEQUENCE  START WITH  INCREMENT BY  MAXVALUE  MINVALUE  NOCYCLE;</code>

in:

• : The name of the sequence.
• : The start value of the sequence.
• : The incremental value of the sequence, default is 1.
• : The maximum value of the sequence, defaulting to infinity.
• : The minimum value of the sequence, default is 1.
• NOCYCLE : The specified sequence does not cycle after reaching the maximum value.

For example, to create a sequence named MY_SEQUENCE with a starting value of 1, an increment value of 2, a maximum value of 10000, and so on:

 <code class="sql">CREATE SEQUENCE MY_SEQUENCE START WITH 1 INCREMENT BY 2 MAXVALUE 10000 NOCYCLE;</code>

3. View sequence: You can view the created sequence using the following query:

 <code class="sql">SELECT sequence_name, min_value, max_value, increment_by FROM user_sequences WHERE sequence_name = '';</code>

For example, to view information about the MY_SEQUENCE sequence, and so on:

 <code class="sql">SELECT sequence_name, min_value, max_value, increment_by FROM user_sequences WHERE sequence_name = 'MY_SEQUENCE';</code>

4. Using Sequence: You can use the NEXTVAL function to get the next value of the sequence:

 <code class="sql">SELECT NEXTVAL('');</code>

For example, to get the next value of the MY_SEQUENCE sequence, and so on:

 <code class="sql">SELECT NEXTVAL('MY_SEQUENCE');</code>

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