如果返回多个值,如何引用游标的特定值?
DECLARE
X INTEGER;
CURSOR c1 IS SELECT col1, col2, col3.....;
BEGIN
OPEN c1;
LOOP
EXIT WHEN c1%NOTFOUND;
FETCH (col2 from c1) INTO X;
END LOOP;
END;
答案 0 :(得分:13)
你为什么要这样?据推测,如果您在游标声明中选择了三列,则需要在代码中使用所有三列,因此您需要将所有三列提取到三个单独的局部变量中,即
DECLARE
x integer;
y integer;
z integer;
CURSOR c1
IS SELECT column1, column2, column3
FROM some_table;
BEGIN
OPEN c1;
LOOP
FETCH c1
INTO x, y, z;
EXIT WHEN c1%NOTFOUND;
END LOOP;
CLOSE c1;
END;
或者,您可以根据游标声明声明记录类型并获取
DECLARE
CURSOR c1
IS SELECT column1, column2, column3
FROM some_table;
c1_rec c1%ROWTYPE;
BEGIN
OPEN c1;
LOOP
FETCH c1
INTO c1_rec;
dbms_output.put_line( c1_rec.column2 );
EXIT WHEN c1%NOTFOUND;
END LOOP;
CLOSE c1;
END;
您还可以完全摆脱显式循环,这通常是首选方法,因为您不必担心游标泄漏和(在现代版本中)Oracle可以自动为您进行批量收集
DECLARE
CURSOR c1
IS SELECT column1, column2, column3
FROM some_table;
BEGIN
FOR c1_rec IN c1
LOOP
dbms_output.put_line( c1_rec.column2 );
END LOOP;
END;