我正在尝试在 phpMyAdmin 中创建以下存储过程。但是,我不断收到此错误:#1313 - RETURN is only allowed in a FUNCTION
CREATE PROCEDURE IS_POINT_IN_POLYGON()
BEGIN
DECLARE n INT DEFAULT 0;
DECLARE pX DECIMAL(19,16);
DECLARE pY DECIMAL(19,16);
DECLARE ls LINESTRING;
DECLARE poly1 POINT;
DECLARE poly1X DECIMAL(19,16);
DECLARE poly1Y DECIMAL(19,16);
DECLARE poly2 POINT;
DECLARE poly2X DECIMAL(19,16);
DECLARE poly2Y DECIMAL(19,16);
DECLARE i INT DEFAULT 0;
DECLARE result INT(1) DEFAULT 0;
SET pX = X(p);
SET pY = Y(p);
SET ls = ExteriorRing(poly);
SET poly2 = EndPoint(ls);
SET poly2X = X(poly2);
SET poly2Y = Y(poly2);
SET n = NumPoints(ls);
WHILE i<n DO
SET poly1 = PointN(ls, (i+1));
SET poly1X = X(poly1);
SET poly1Y = Y(poly1);
IF ( ( ( ( poly1X <= pX )
&& ( pX < poly2X ) ) || ( ( poly2X <= pX )
&& ( pX < poly1X ) ) )
&& ( pY > ( poly2Y - poly1Y ) * ( pX - poly1X ) / ( poly2X - poly1X ) + poly1Y ) ) THEN
SET result = !result;
END IF;
SET poly2X = poly1X;
SET poly2Y = poly1Y;
SET i = i + 1;
END WHILE;
RETURN result;
END//
如何解决这个问题?在 SQL 窗格中,我记得将分隔符更改为 // .
有什么建议吗?
错误消息准确地告诉您问题所在 - 您不能在
RETURN
中使用 PROCEDURE
。创建一个 FUNCTION
来代替 (CREATE FUNCTION
),它可以返回一个值。
CREATE FUNCTION <FunctionName> RETURNS <DataType>
我在下面遇到了同样的错误:
错误 1313 (42000):仅在函数中允许返回
当我使用 RETURN 语句创建过程时,如下所示:
DELIMITER $$
CREATE PROCEDURE my_proc(INOUT value INT)
BEGIN
RETURN 2 + value;
END$$
DELIMITER ;
因此,我将
RETURN
语句替换为 SELECT 语句,如下所示,然后我可以毫无错误地创建过程:
DELIMITER $$
CREATE PROCEDURE my_proc(INOUT value INT)
BEGIN
-- RETURN 2 + value;
SELECT 2 + value INTO value;
END$$
DELIMITER ;