Trigger updating inserting 2016 all new datings botswana
A scalar value may also be associated with an UPDATE statement, though this is not very common (as UPDATE statements are usually looking for dynamic defaults): keyword arguments also accept Python functions.These functions are invoked at the time of insert or update if no other value for that column is supplied, and the value returned is used for the column’s value.create or replace trigger update_emp_thru_outemp_view instead of update on outemp referencing new as new begin update emp set ename = :new.ename, empno = :new.empno, job = :new.job, mgr = :new.mgr, hiredate = :new.hiredate, sal = :new.sal, comm = :new.comm, deptno = ( select deptno from dept where dname = :new.dname ) where empno = :old.empno; if ( sql%rowcount = 0 ) then raise_application_error ( -20001, 'Error updating the outemp view !!!' ); end if; end; select * from emp where ename = 'C Farmer'; EMPNO ENAME JOB MGR HIREDATE SAL COMM DEPTNO ---------- ---------- --------- ---------- --------- ---------- ---------- 3456 C Farmer DBA 7839 01-JUL-02 4000 4 40 1 row selected.
Above, the value “12” will be bound as the column value during an INSERT if no other value is supplied.
When the statement is executed with a single set of parameters (that is, it is not an “executemany” style execution), the returned is similar to that of a regular SQL default; if it’s placed on a primary key column for a database which doesn’t have a way to “postfetch” the ID, and the statement is not “inlined”, the SQL expression is pre-executed; otherwise, SQLAlchemy lets the default fire off on the database side normally. This is becaue the “post-fetch” operation requires that the primary key value already be available, so that the row can be selected on its primary key.
For a server-generated primary key value, all databases provide special accessors or other techniques in order to acquire the “last inserted primary key” column of a table.
Although in some cases, the function is “pre-executed” in a SELECT statement of its own beforehand.
This happens when all of the following is true: Whether or not the default generation clause “pre-executes” is not something that normally needs to be considered, unless it is being addressed for performance reasons.
Below illustrates a crude “sequence” that assigns an incrementing counter to a primary key column: It should be noted that for real “incrementing sequence” behavior, the built-in capabilities of the database should normally be used, which may include sequence objects or other autoincrementing capabilities.