Oracle creates primary key self-add table (SQL statement implementation) and trigger application _oracle

1. Create a table

Copy Code code as follows:

Createtabletest_increase (
Useridnumber (Ten) notnullprimarykey,/* primary key, automatically increase * *
USERNAMEVARCHAR2 (20)
);

2. Create automatic growth sequence

Copy Code code as follows:

Createsequencetestincrease_sequence
incrementby1--add a few at a time
startwith1--counting starting from 1
nomaxvalue--do not set maximum value, set maximum: maxvalue9999
nocycle--has been accumulated, does not cycle
CACHE10;

3. Create triggers

Copy Code code as follows:

Createtriggertest_increasebefore
insertontest_increaseforeachrow/* for each row to detect whether the trigger/
Begin
selectTestIncrease_Sequence.nextvalinto:New.useridfromdual;
End
* Exit Sqlplus Line Edit * *

4. Submit

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Commit

5, testing
Insertinto

Copy Code code as follows:

Test_increase (Username) VALUES (' Test ');