Wie zwei verwendet werden, während Syntax in Mysql Procecure

Question

Ich möchte zwei While Syntax schreiben.

Die Ergebnisse, die ich erwarte, sind wie folgt.

wenn 'H'
tagName1, tagName2, tagname3
, wenn 'D'
tagName1, tagName2, tagname3
wenn 'M'
tagName1, tagName2, tagname3
als 'Y'
tagName1 tagName2, tagname3

Aber es hat nicht funktioniert ....

B elow ist der Code, den ich geschrieben habe, während ich ihn nur einmal spiele.

Jede Beratung, bitte ..

DECLARE tagList varchar(255) DEFAULT 'tagName1,tagName2,tagName3'; 
DECLARE tagTypeList varchar(150) DEFAULT 'H,D,M,Y'; 
WHILE tagTypeList != '' DO 
WHILE tagList != '' DO 
    SET tagNameArray = SUBSTRING_INDEX(tagList, ',', 1); 
    SET tagTypeArray = SUBSTRING_INDEX(tagTypeList, ',', 1);  

IF(tagTypeArray = 'H') THEN 
     SET aDate = (SELECT (DATE_ADD(nDateTime, INTERVAL -1 HOUR))); 
     SET ago_Y = (SELECT DATE_FORMAT(aDate,'%Y')); 
     SET ago_M = (SELECT DATE_FORMAT(aDate,'%m')); 
     SET ago_D = (SELECT DATE_FORMAT(aDate,'%d')); 
     SET ago_H = (SELECT DATE_FORMAT(aDate,'%H')); 
     SET ago_W = (SELECT DATE_FORMAT(aDate,'%w')); 

ELSEIF(tagTypeArray = 'D') THEN 
     SET aDate = (SELECT (DATE_ADD(nDateTime, INTERVAL -1 DAY))); 
     SET ago_Y = (SELECT DATE_FORMAT(aDate,'%Y')); 
     SET ago_M = (SELECT DATE_FORMAT(aDate,'%m')); 
     SET ago_D = (SELECT DATE_FORMAT(aDate,'%d')); 

     SET ago_H = 0; 
     SET ago_W = 0; 

ELSEIF(tagTypeArray = 'M') THEN 
     SET aDate = (SELECT (DATE_ADD(nDateTime, INTERVAL -1 MONTH))); 
     SET ago_Y = (SELECT DATE_FORMAT(aDate,'%Y')); 
     SET ago_M = (SELECT DATE_FORMAT(aDate,'%m')); 

     SET ago_D = 0; 
     SET ago_H = 0; 
     SET ago_W = 0; 

ELSEIF(tagTypeArray = 'Y') THEN 
     SET aDate = (SELECT (DATE_ADD(nDateTime, INTERVAL -1 YEAR))); 
     SET ago_Y = (SELECT DATE_FORMAT(aDate,'%Y')); 
     SET ago_M = 0; 
     SET ago_D = 0; 
     SET ago_H = 0; 
     SET ago_W = 0;   
END IF; 


    SET selectValue = (SELECT tagvalue FROM datasource WHERE tagname = tagNameArray and tagtype = tagTypeArray and y=ago_Y and m=ago_M and d=ago_D and h=ago_H); 

    IF(selectValue IS NULL OR selectValue = '') 
     THEN 

      SET old_Value_3M = (Select LastValue from BwAnalogTable where TagName = tagNameArray and LogDate >= ago_3M order by LogDate desc, LogTime desc limit 1); 
      # Here Insert Querty 
    END IF;  



    IF LOCATE(',', tagList) > 0 THEN   
     SET tagList = SUBSTRING(tagList, LOCATE(',', tagList) + 1); 
    ELSE 
     SET tagList = ''; 
    END IF; 
END WHILE; 


    IF LOCATE(',', tagTypeList) > 0 THEN 
     SET tagTypeList = SUBSTRING(tagTypeList, LOCATE(',', tagTypeList) + 1); 
    ELSE 
     SET tagTypeList = ''; 
    END IF; 
END WHILE; 

Answer 1

Ich habe den Code geändert, wie unten gezeigt.

DECLARE done INT DEFAULT FALSE; 
DECLARE tagType2 VARCHAR(255) DEFAULT ''; 
DECLARE tagName2 VARCHAR(255) DEFAULT ''; 
DECLARE tagType_Cur CURSOR for select tagType from tbtagtype; 
DECLARE tagName_Cur CURSOR for select tagName from tbtaglist; 

OPEN tagType_Cur; 
     LOOP1: LOOP 
       FETCH tagType_Cur INTO tagType2;      
       IF done THEN        
         CLOSE tagType_Cur; 
         LEAVE LOOP1; 
       END IF; 
      ########## here insert your core query ###############    
     OPEN tagName_Cur; 
       LOOP2: LOOP 
        FETCH tagName_Cur INTO tagName2; 

        IF done THEN 
         CLOSE tagName_Cur; 
         SET done = FALSE; 
         LEAVE LOOP2; 
        END IF; 
        ########## here insert your core query ############### 
        END LOOP LOOP2;      
     END LOOP LOOP1;