Trigger i Oracle for automatisk at øge et felt og indsætte i tilknytningstabel

Du kan bruge returning into klausul i insert sætning for at returnere users_id værdi efter en ny post er blevet indsat i table1 . Du kan også bruge user_seq.currval for at få den aktuelle værdi af sekvensen. Her er et eksempel (I dette eksempel er en simpel lagret procedure blevet implementeret for at demonstrere brugen af ​​insert into klausul. Du kan implementere en lignende lagret procedure i henhold til dine krav):

SQL> create table Tb_table_1(
  2    user_id number primary key,
  3    field_1 number
  4  );

Table created

SQL> 
SQL> create table Tb_table_2(
  2    user_id number references tb_table_1(user_id),
  3    name1 varchar2(17)
  4  );

Table created

SQL> create sequence user_seq
  2  start with 1
  3  increment by 1
  4  nomaxvalue;

Sequence created

SQL> 
SQL> create trigger user_trigger
  2  before insert on tb_table_1
  3  for each row
  4  begin
  5    select user_seq.nextval into :new.user_id from dual;
  6  end;
  7  /

Trigger created

  SQL> create or replace procedure Insert_Record
  2  is
  3    l_cur_id number;
  4  begin
  5    insert into Tb_table_1(Field_1)
  6      values(123)
  7    returning user_id into l_cur_id; -- store user_id of the new inserted record
  8    for i in 1..5                    -- in a local variable for later use  
  9    loop
 10      insert into tb_table_2(user_id, name1)  -- insert a bunch of sample data into table2 using previously stored user_id.
 11        values(l_cur_id, dbms_random.string('l', 7));
 12    end loop
 13    commit;
 14  end;
 15  /

Procedure created

SQL> select * from tb_table_1;

   USER_ID    FIELD_1
---------- ----------

SQL> select * from tb_table_2;

   USER_ID NAME1
---------- -----------------



SQL> exec insert_record;

PL/SQL procedure successfully completed

SQL> select * from tb_table_1
  2  ;

   USER_ID    FIELD_1
---------- ----------
         1        123

SQL> select * from tb_table_2;

   USER_ID NAME1
---------- -----------------
         1 jzsdbna
         1 ozbibgs
         1 btxrxcm
         1 hxwwpzc
         1 sdjbwzi

SQL> 

I Oracle 11g og fremefter kan du direkte tildele sekvensværdi til en variabel:

:new.users_id := user_seq.nextval;