Some errors with the code

Question

hello all!
i am trying to write simple code but have some errors.
DECLARE
id NUMBER;
BEGIN
id:=SELECT id from technician where salary=(select MIN(salary) from technician);
DBMS_OUTPUT.put_line(id);
END;

Answer 1

Your simple program becomes complex! As pointed out, it will blow up if your query returns more than one row. If you're just doodling with your code, you can add "and rownum=1" to your where clause. That will prevent the "too many rows returned" exception. Of course, it is basically randomly picking one of several values in the DB, so it's not good for production code.
For real code, there are at least two common options:
(1) Use your select to create a cursor, which lets you loop through each matching row. Good when multiple rows are normal and you really want to use them all.
(2) Create an integer variable, such as row_count. Select count(*) into row_count ... from technician t where salary....
If row_count = 1 then use the assignment you were going to do. Otherwise, stop processing and log an error (too many or too few rows returned...).
This is good when you expect EXACTLY one technician to have that salary, and anything else is an error.
Andy