MySQL的程序語法錯誤

Question

我得到通過發送下面的查詢（MYSQL 5.0）的錯誤：

DELIMITER // 
    CREATE PROCEDURE relationTable() 
    BEGIN 
     DECLARE articlecount int; 
     DECLARE keywordcount int; 
     DECLARE articlehits int; 
     DECLARE ac int DEFAULT 0; 
     DECLARE kc int; 
     DECLARE articleid int; 
     DECLARE word varchar(100); 
     DECLARE word_id int; 
     SET articlehits = 0; 
     SET articlecount = (SELECT count(id) from articles); 
     SET keywordcount = (SELECT count(id) from keywords); 
     outerloop: WHILE (ac < articlecount) DO 
      SET kc = 0; 
      SET articleid = (SELECT id from articles LIMIT 1 OFFSET ac); 
      innerloop: WHILE (kc < keywordcount) DO 
       IF (articlehits < 5) THEN 
        SELECT keyword, id INTO word, word_id from keywords LIMIT 1 OFFSET kc; 
        IF (0 < (SELECT COUNT(id) from articles WHERE id=articleid AND CONCAT(title, " ",text) REGEXP word)) THEN 
         INSERT INTO articles (id, articleID, keywordID, type) VALUES(NULL, articleid, word_id, 'type1'); 
         SET articlehits = articlehits + 1; 
        END IF; 
        SET kc = kc + 1; 
       ELSE 
        SET kc = keywordcount; 
       END IF; 
      END WHILE innerloop; 
      SET ac = ac + 1; 
     END WHILE outerloop; 
    END; 
    // 
    DELIMITER ; 

這將產生以下錯誤：

ERROR 1064 (42000): You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near 'LIMIT 1 OFFSET ac); innerloop: WHILE (kc < keywordcount) DO TO word, word_id from' at line 15

任何想法，爲什麼出現這種情況？

（寫到這來創建文章和關鍵字之間的關係表，以便在文章視圖智能鏈接。）

Answer 1

儘量去除，而標籤：

WHILE (ac < articlecount) DO 
      SET kc = 0; 
      SET articleid = (SELECT id from articles LIMIT 1 OFFSET ac); 
      WHILE (kc < keywordcount) DO 
       IF (articlehits < 5) THEN 
        SELECT keyword, id INTO word, word_id from keywords LIMIT 1 OFFSET kc; 
        IF (0 < (SELECT COUNT(id) from articles WHERE id=articleid AND CONCAT(title, " ",text) REGEXP word)) THEN 
         INSERT INTO articles (id, articleID, keywordID, type) VALUES(NULL, articleid, word_id, 'type1'); 
         SET articlehits = articlehits + 1; 
        END IF; 
        SET kc = kc + 1; 
       ELSE 
        SET kc = keywordcount; 
       END IF; 
      END WHILE; 
      SET ac = ac + 1; 
     END WHILE; 

Answer 2

MySQL有連接特定用戶定義的變量形式爲@varname，並聲明您在代碼示例中使用的類型的過程變量。根據我對程序的經驗，有時只允許其中一種類型，如果我正確記得，那麼SELECTing INTO時可能會出現其中一種情況。您可以嘗試在這裏使用用戶定義的變量，如下所示：

SET articleid = (SELECT id from articles LIMIT 1 OFFSET ac); 
    innerloop: WHILE (kc < keywordcount) DO 
     IF (articlehits < 5) THEN 
      SELECT keyword, id INTO @word, @word_id from keywords LIMIT 1 OFFSET kc; 

只是一個想法。

Answer 3

一個問題可能是SET acticleid =（SELECT ...）。試着用SELECT .. INTO：

SELECT id INTO @articleid FROM articles LIMIT 1 OFFSET ac; 

可變LIMIT在存儲過程中僅在新的MySQL版本的支持。請注意，由於您沒有ORDER BY，您將得到一個隨機行。它看起來像你想用CURSOR來代替。請參閱docs。

Answer 4

在看似過分危險的情況下，我相信你應該重寫這個過程來使用遊標遍歷數據庫，而不是使用LIMIT進行單獨選擇。

看到Cursors in MySQL Docs

Answer 5

感謝您的幫助迄今。 Tom Haws的想法被證明是正確的。 SELECT INTO語句的變量必須是用戶定義的。 我編輯我的代碼使用遊標，和用戶定義的變量如下：

delimiter // 
CREATE PROCEDURE relationTable() 
BEGIN 
    DECLARE articlehits int; 
    DECLARE looparticles int DEFAULT TRUE; 
    DECLARE loopwords int DEFAULT TRUE; 
    DECLARE done INT DEFAULT FALSE;  
    DECLARE keywordcursor CURSOR FOR SELECT keyword, id FROM keywords; 
    DECLARE articlecursor CURSOR FOR SELECT id FROM articles; 
    DECLARE CONTINUE HANDLER FOR NOT FOUND SET done = TRUE; 
    OPEN articlecursor; 
    WHILE (looparticles) DO 
     FETCH articlecursor INTO @articleid; 
     IF done THEN SET looparticles = FALSE; 
     ELSE 
      SET articlehits = 0; 
      OPEN keywordcursor; 
      WHILE (loopwords) DO 
       FETCH keywordcursor INTO @word, @wordid; 
       IF (articlehits < 5) AND NOT done THEN 
        IF (0 < (SELECT COUNT(id) FROM articles WHERE id=@articleid AND CONCAT(title, " ", text) REGEXP @word)) THEN 
         INSERT INTO keyword_article_rel (id, meldungID, wordID) VALUES(NULL, @articleid, @wordid); 
         SET articlehits = articlehits + 1; 
        END IF; 
       ELSE 
        SET loopwords = FALSE; 
        CLOSE keywordcursor; 
        SET done = FALSE; 
       END IF; 
      END WHILE; 
     END IF; 
    END WHILE; 
    CLOSE articlecursor; 
    END; 
    // 
    delimiter ; 

現在我得到，我真的無法解釋的其他錯誤：

ERROR 1064 (42000): You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near '; DECLARE CONTINUE HANDLER FOR NOT FOUND SET done = TRUE; OPEN articlecursor; W' at line 6

這個錯誤讓我困惑因爲它不會對處理程序有問題。該處理程序在mysql文檔的example中聲明。問題可能是我不能創建兩個這樣的遊標？