使用從MS-SQL轉換到MySQL的存儲過程的IF語句的語法錯誤

Question

我正在將存儲過程從MS-SQL轉換爲MySQL。它基於Directed Acyclic Graphs，但是我得到一個語法錯誤。

原始MS-SQL腳本清單2在下頁中： http://www.codeproject.com/Articles/22824/A-Model-to-Represent-Directed-Acyclic-Graphs-DAG-o

我得到的錯誤是： ＃1064 - 你在你的SQL語法錯誤;檢查與您的MySQL服務器版本相對應的手冊，以在'DECLARE varId int; INSERT INTO邊緣（startVertex，連接」在第36行

的MySQL代碼：

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 ; 

這正常不IF語句，所以我想我的語法是有點不對任何想法

Answer 1

？作爲DECLARE Syntax下稱：

DECLARE只允許內部BEGIN ... END複合語句，並且必須是在它的開始，任何其他語句之前