MYSQL級聯查詢，包括向上向下的級聯

-- 名稱：mysql遞歸查詢存儲過程(2014-04-05) 
-- 入:@table  表名[varchar(200)]
-- 入:@field  要查詢返回的字段名(例如:  name,age,remark)[text]
-- 入:@order  返回結果的排序(例如 name desc,age asc)[text]
-- 入:@idName 主鍵列名[varchar(200)]
-- 入:@pidName父鍵列名[varchar(200)]
-- 入:@id     主鍵值[varchar(200)],不能爲null,若是值是null,說明要查詢所有,請本身查詢
-- 入:@upDown 向上級聯仍是向下級聯,1=上 0=下[int]
-- 入:@self   是否包含本身 1=是 0=否[int]
-- 返回查詢結果集
DROP PROCEDURE IF EXISTS Query_Dg;
CREATE PROCEDURE Query_Dg
(
	IN table_   VARCHAR(200),
	IN field_   TEXT,
	IN order_   TEXT,
	IN idName_  VARCHAR(200),
	IN pidName_ VARCHAR(200),
	IN id_      VARCHAR(200),
	IN upDown_  INT,
	IN self_    INT
)
BEGIN
DECLARE _sqlStr VARCHAR(4000);  -- 動態sql
DECLARE _idParam VARCHAR(4000);  -- id存放的變量
DECLARE _idSet VARCHAR(4000);  -- 結果
SET @_idSet = '';
-- 查詢id開始
IF(self_ = 1)THEN -- 包含本身
    SET @_idSet = id_;
END IF;
-- 遞歸開始
IF(upDown_ = 1)THEN -- 向上遞歸
    SET @_sql = CONCAT('SELECT ',pidName_,' INTO @_idParam FROM ',table_,' WHERE ',idName_,' = ?');
ELSE  -- 向下遞歸
    SET @_sql = CONCAT('SELECT GROUP_CONCAT(',idName_,') INTO @_idParam FROM ',table_,' WHERE FIND_IN_SET(',pidName_,', ?) > 0');
END IF;
SET @_idParam = id_;    -- 輸入參數使用時不能 @
PREPARE _sqlStr FROM @_sql;
EXECUTE _sqlStr USING @_idParam;
WHILE @_idParam IS NOT NULL DO
    SET @_idSet = CONCAT(@_idSet,',',@_idParam);
    EXECUTE _sqlStr USING @_idParam;
END WHILE;
-- 查詢id結束
SET @_sql = CONCAT('SELECT ',field_,' FROM ',table_,' WHERE FIND_IN_SET(',idName_,', ? ) > 0 order by ',order_); -- 查詢
DEALLOCATE PREPARE _sqlStr; -- 解除預編譯
PREPARE _sqlStr FROM @_sql; -- 從新預編譯
EXECUTE _sqlStr USING @_idSet;
DEALLOCATE PREPARE _sqlStr;
END