Duloxetine 20mg pills $162.00 OracleAfter pointing out how not to create auto increment columns in Oracle, duloxetine 20mg pills $162.00 I suppose I should point out how to create auto increment columns in oracle.

Duloxetine 20mg pills $162.00 Many will gripe about this not being a standard feature in Oracle, duloxetine 20mg pills $162.00 but when it’s as easy as two more commands after your CREATE TABLE command I can’t see any good reason to use fancy SQL on every insert.

Duloxetine 20mg pills $162.00 First let’s create a simple table to play with.

Duloxetine 20mg pills $162.00 SQL> CREATE TABLE test
(id NUMBER PRIMARY KEY, duloxetine 20mg pills $162.00
name VARCHAR2(30));

Duloxetine 20mg pills $162.00 Table created.

Duloxetine 20mg pills $162.00 Now we’ll assume we want ID to be an auto increment field. Duloxetine 20mg pills $162.00 First we need a sequence to grab values from.

Duloxetine 20mg pills $162.00 SQL> CREATE SEQUENCE test_sequence
START WITH 1
INCREMENT BY 1;

Duloxetine 20mg pills $162.00 Sequence created.


Duloxetine 20mg pills $162.00 Now we can use that sequence in an BEFORE INSERT trigger on the table.

Duloxetine 20mg pills $162.00 CREATE OR REPLACE TRIGGER test_trigger
BEFORE INSERT
ON test
REFERENCING NEW AS NEW
FOR EACH ROW
BEGIN
SELECT test_sequence.nextval INTO :NEW.ID FROM dual;
END;
/

Duloxetine 20mg pills $162.00 Trigger created.

Duloxetine 20mg pills $162.00 This trigger will automatically grab the next value from the sequence we just created and substitute it into the ID column before the insert is completed.

Duloxetine 20mg pills $162.00 Now we’ll do some inserts:

Duloxetine 20mg pills $162.00 SQL> INSERT INTO test (name) VALUES ('Jon');

Duloxetine 20mg pills $162.00 1 row created.

Duloxetine 20mg pills $162.00 SQL> INSERT INTO test (name) VALUES ('Bork');

Duloxetine 20mg pills $162.00 1 row created.

Duloxetine 20mg pills $162.00 SQL> INSERT INTO test (name) VALUES ('Matt');

Duloxetine 20mg pills $162.00 1 row created.

Duloxetine 20mg pills $162.00 SQL> SELECT * FROM test;

Duloxetine 20mg pills $162.00 ID NAME
---------- ------------------------------
1 Jon
2 Bork
3 Matt

Duloxetine 20mg pills $162.00 Because the sequence is updated independent of the rows being committed there will be no conflict if multiple users are inserting into the same table simultaneously.

Duloxetine 20mg pills $162.00 If you need to capture the value of the auto increment column you’ll want to check out my other article Oracle Auto increment Columns – Part 2

Duloxetine 20mg pills $162.00 Matt has posted a similar method in which he uses a sequence in the insert eliminating the need for the trigger. Duloxetine 20mg pills $162.00 That will work just as well without the need for the trigger. Duloxetine 20mg pills $162.00 The only drawback to this method is slightly longer SQL commands.

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