If there are some fields in A table, table B is empty table, when the update A table, will update the content on B for use in the table

CodePudding user response:

The main trigger is how to write

CodePudding user response:

 
Write you a example 
 -
SQL> 
SQL> Create table ta (int id, name varchar (10), the age int); 
The Table created 
SQL> The create table TB (id int, old_name varchar (10), new_name varchar (10)); 
The Table created 
SQL> Create the trigger tri_ta_update 
2 before the update on ta 
3 for each row 
4 the begin 
Insert into 5 TB (id, old_name, new_name) 
6 values (: new id, : old. Name, : new, name); 
7 the end; 
8/
The Trigger created 
SQL> The begin 
2 insert into ta values (100, 'zs, 100); 
3 the update ta set name='ABC'; 
4 the update ta set name='zxy'; 
5 the end; 
6/
PL/SQL procedure successfully completed 
SQL> Col id format a5; 
SQL> Select * from ta; 
ID NAME AGE 
-- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- 
100 zxy 100 
SQL> Select * from TB; 
ID OLD_NAME NEW_NAME 
-- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- 
100 zs ABC 
100 ABC zxy 
SQL> Drop table ta purge; 
Table dropped 
SQL> Drop table TB purge; 
Table dropped 

SQL> 

CodePudding user response:

If I want to update the content of time and which update operations (update the insert delect), are written in the B on the table, can realize a

CodePudding user response:

Please, for example, had better use excel to draw once, what do you want to achieve,

CodePudding user response:

CodePudding user response:

CodePudding user response:

I drew this picture, can achieve it