如何为变量选择一个变量？

我有以下代码:

DECLARE
  v_oras locations.city%TYPE;
BEGIN
  SELECT l.city FROM locations l,departments d WHERE l.location_id = d.location_id AND d.department_id = 30;
END;
/

如何将select分配给之前声明的变量？

使用SELECT INTO声明.

DECLARE
  v_oras locations.city%TYPE;
BEGIN
  SELECT l.city 
  INTO v_oras 
  FROM locations l
  JOIN departments d ON l.location_id = d.location_id
  WHERE d.department_id = 30;
END;

这可以用于从SELECT语句返回的多个值以及分配的INTO声明变量.