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我正在将存储过程从 MS-SQL 转换为 MySQL。它基于有向无环图，但出现语法错误。

原始 MS-SQL 脚本在以下页面的清单 2 中：http: //www.codeproject.com/Articles/22824/A-Model-to-Represent-Directed-Acyclic-Graphs-DAG-o

我得到的错误是：#1064 - 你的 SQL 语法有错误；检查与您的 MySQL 服务器版本相对应的手册，以获取在 'DECLARE varId int; 附近使用的正确语法；INSERT INTO 边缘（第 36 行的 startVertex, en'

MySQL 代码：

DELIMITER //
CREATE PROCEDURE AddEdge(
IN iStartVertexId varchar(36),
IN iEndVertexId varchar(36),
IN iSource varchar(150)
)

MAIN_BLOCK: BEGIN

DECLARE counter int default 0;
SET counter = (SELECT id 
   FROM edges 
   WHERE startVertex = iStartVertexId 
     AND endVertex = iEndVertexId 
     AND hops = 0);
IF counter > 0 THEN
   BEGIN
      LEAVE MAIN_BLOCK;
   END;
END IF;

SET counter = 0;
SET counter = (SELECT Id 
                     FROM edges
                     WHERE StartVertex = @EndVertexId 
                       AND EndVertex = @StartVertexId);

IF iStartVertexId = iEndVertexId 
      OR counter > 0
THEN
BEGIN

     LEAVE MAIN_BLOCK;
END;
END IF;


DECLARE varId int;

INSERT INTO edges (
     startVertex,
     endVertex,
     hops,
     source)
  VALUES (
     iStartVertexId,
     iEndVertexId,
     0,
     iSource);

SELECT varId = LAST_INSERT_ID();
UPDATE edges
  SET entryEdgeId = varId
    , exitEdgeId = varId
    , directEdgeId = varId 
  WHERE id = varId;

-- step 1: A's incoming edges to B
INSERT INTO edges (
     entryEdgeId,
     directEdgeId,
     exitEdgeId,
     startVertex,
     endVertex,
     hops,
     source) 
  SELECT id
     , varId
     , varId
     , startVertex 
     , iEndVertexId
     , hops + 1
     , iSource
  FROM edges
  WHERE endVertex = iStartVertexId;

-- step 2: A to B's outgoing edges
INSERT INTO edges (
     entryEdgeId,
     directEdgeId,
     exitEdgeId,
     startVertex,
     endVertex,
     hops,
     source) 
  SELECT varId
     , varId
     , id
     , iStartVertexId 
     , endVertex
     , hops + 1
     , iSource
  FROM edges
  WHERE startVertex = iEndVertexId;

-- step 3: A’s incoming edges to end vertex of B's outgoing edges
INSERT INTO edges (
     entryEdgeId,
     directEdgeId,
     exitEdgeId,
     startVertex,
     endVertex,
     hops,
     source)
  SELECT A.id
     , varId
     , B.id
     , A.startVertex 
     , B.endVertex
     , A.hops + B.hops + 1
     , iSource
  FROM edges A
     CROSS JOIN edges B
  WHERE A.endVertex = iStartVertexId
    AND B.startVertex = iEndVertexId;

END //
DELIMITER ;

如果没有 IF 语句，这可以正常工作，所以我认为我的语法有点错误。有任何想法吗？

4

1 回答 1

1

如DECLARE语法下所述：

DECLARE只能在BEGIN ... END复合语句中使用，并且必须位于其开头，在任何其他语句之前。

于 2012-08-30T14:16:26.017 回答