Trigger ' SA. U_USER_INFO_TRG ' Invalid and failed to re-validate--oracle sequence

Program development times wrong: Trigger ' SA. U_USER_INFO_TRG ' is invalid and has not been re-verified
Opens the definition of the trigger, executes the statement within it, and discovers that the sequence u_user_info_seq is undefined.
What is a sequence?
The sequence corresponds to those self-increasing IDs in SQL Server, with attributes such as step size, maximum value, and minimum value.
is custom in Oracle.

The topic of this article is to increase the primary key of a table by creating an Oracle sequence and a trigger.

1. First create the sequence, the syntax format of the Oracle sequence is:
CREATE SEQUENCE sequence Name
[INCREMENT by N]
[START with N]
[{Maxvalue/minvalue n| Nomaxvalue}]
[{cycle| Nocycle}]
[{CACHE n| NOCACHE}];

1) INCREMENT by is used to define the step of the sequence, and if omitted, the default is 1, and if a negative value is present, the values for the Oracle sequence are decremented by this step.

2) START with defines the initial value of the sequence (that is, the first value produced), which defaults to 1.

3) MAXVALUE defines the maximum value that the sequence generator can produce. Option Nomaxvalue is the default option, which means that there is no maximum value defined, at which point the system can produce a maximum of 10 27 times for incrementing an Oracle sequence, and for a descending sequence, the maximum value is-1.

4) MinValue defines the minimum value that the sequence generator can produce. Option Nomaxvalue is the default option, which means there is no minimum definition, and for a descending sequence, the minimum value that the system can produce is 10 of the 26 square, and for the increment sequence, the minimum value is 1.

5) cycle and nocycle indicate whether the sequence generator will loop if its value reaches the limit value. The cycle represents the loop, and the nocycle represents no loops. If the loop is, it loops to the minimum when the increment sequence reaches its maximum value, and to the maximum value when the descending sequence reaches the minimum value. If you do not loop, the error occurs when the limit value is reached and the new value continues to be generated.

6) the cache (buffer) defines the size of the memory block that holds the sequence, which defaults to 20. NoCache indicates that the sequence is not buffered in memory. Memory buffering of a sequence can improve the performance of the sequence.

2. The syntax for deleting an oracle sequence is the drop SEQUENCE sequence name;

Suppose there is a table test whose primary key is test_id
1) set up the increment sequence seq_test:
Create sequence Seq_test
Increment by 1
Start with 1
MinValue 1 Nomaxvalue
Nocylce

2) Create a trigger that uses an ascending primary key value for which the Oracle sequence goes when there is data inserted into the table test
Create trigger trg_test before insert on TEST
For each row
Begin
Select Seq_test.nextval into:new. TEST_ID from dual;
End

At this point, the creation is complete!

Of course, instead of using triggers, you can call a sequence in an SQL statement at insert time, for example
INSERT into TEST values (Seq_test.nextval, ...)

Above is a quote: Http://www.cnblogs.com/WangPB/archive/2010/07/13/1776766.html's article.

Trigger ' SA. U_USER_INFO_TRG ' Invalid and failed to re-validate--oracle sequence