MySql學習心得之存儲過程

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    先來看段mysql查詢文章回復語句:
    代碼如下:
    #查詢文章回復
    ------------------------------
    --Procedurestructurefor`sp_select_reply_article`
    ------------------------------
    DROPPROCEDUREIFEXISTS`sp_select_reply_article`;
    DELIMITER;;
    CREATEDEFINER=`root`@`localhost`PROCEDURE`sp_select_reply_article`(IN`ra_id`int,IN`pagefrom`int,IN`pagesize`int)
    BEGIN
    #Routinebodygoeshere...
    SET@ra_id=ra_id;
    SET@pagefrom=pagefrom;
    SET@pagesize=pagesize;
    SET@ssra=CONCAT('SELECT*FROMgk_articleWHEREid=?LIMIT?,?');
    PREPAREsqlqueryFROM@ssra;
    EXECUTEsqlqueryUSING@ra_id,@pagefrom,@pagesize;
    END
    DELIMITER;
    #技術(shù)點1:MySql5.1不支持LIMIT參數(shù)(MySql5.5就支持了),如果編寫存儲過程時使用LIMIT做變量,那是需要用動態(tài)SQL來構(gòu)建的,而這樣做性能肯定沒有靜態(tài)SQL好。主要代碼如下:
    代碼如下:
    SET@ssra=CONCAT('SELECT*FROMgk_articleWHEREid=?LIMIT?,?');
    PREPAREsqlqueryFROM@ssra;
    EXECUTEsqlqueryUSING@ra_id,@pagefrom,@pagesize;
    #技術(shù)點2:如果同時需要返回受影響行數(shù)需要在語句后面添加語句:ROW_COUNT()函數(shù),兩條語句之間需要“;”分隔。
    代碼如下:
    #更新數(shù)據(jù)
    ------------------------------
    --Procedurestructurefor`sp_update_permission`
    ------------------------------
    DROPPROCEDUREIFEXISTS`sp_update_permission`;
    DELIMITER;;
    CREATEDEFINER=`root`@`localhost`PROCEDURE`sp_update_permission`(IN`puser_uid`varchar(20),IN`plevel`int,IN`ppower`int)
    BEGIN
    #Routinebodygoeshere...
    SET@puser_uid=puser_uid;
    SET@plevel=plevel;
    SET@ppower=ppower;
    UPDATEgk_permissionSET`level`=@plevel,power=@ppowerWHEREuser_uid=CONVERT(@puser_uidUSINGutf8)COLLATEutf8_unicode_ci;
    END
    DELIMITER;
    #技術(shù)點3:MySQL進行字符串比較時發(fā)生錯誤(Illegalmixofcollations(utf8_unicode_ci,IMPLICIT)and(utf8_general_ci,IMPLICIT)foroperation'='),解決方法:將比較等式一邊進行字符串轉(zhuǎn)換,如改為“CONVERT(b.fullCodeUSINGutf8)COLLATEutf8_unicode_ci”,主要代碼如下:
    代碼如下:
    UPDATEgk_permissionSET`level`=@plevel,power=@ppowerWHEREuser_uid=CONVERT(@puser_uidUSINGutf8)COLLATEutf8_unicode_ci;
    代碼如下:
    #插入數(shù)據(jù)
    ------------------------------
    --Procedurestructurefor`sp_insert_user`
    ------------------------------
    DROPPROCEDUREIFEXISTS`sp_insert_user`;
    DELIMITER;;
    CREATEDEFINER=`root`@`localhost`PROCEDURE`sp_insert_user`(IN`uid`varchar(20),IN`upw`varchar(32),IN`name`varchar(20),IN`sex`int,IN`phone`varchar(20),IN`u_id`int,IN`s_id`int,IN`j_id`int)
    BEGIN
    #Routinebodygoeshere...
    SET@uid=uid;
    SET@upw=upw;
    SET@uname=uname;
    SET@sex=sex;
    SET@phone=phone;
    #由于外鍵約束,所以添加的外鍵字段需要在對應(yīng)外鍵所在表有相應(yīng)數(shù)據(jù)
    SET@u_id=u_id;
    SET@s_id=s_id;
    SET@j_id=j_id;
    SET@verifytime=DATE('0000-00-00');
    INSERTINTOgk_user(uid,upw,uname,sex,phone,u_id,s_id,j_id,verifytime)
      VALUES(@uid,@upw,@uname,@sex,@phone,@u_id,@s_id,@j_id,@verifytime);
    #查詢結(jié)果會自動返回受影響行數(shù)
    END
    DELIMITER;
    代碼如下:
    #根據(jù)ID刪除數(shù)據(jù)
    ------------------------------
    --Procedurestructurefor`sp_delete_exchange_by_id`
    ------------------------------
    DROPPROCEDUREIFEXISTS`sp_delete_exchange_by_id`;
    DELIMITER;;
    CREATEDEFINER=`root`@`localhost`PROCEDURE`sp_delete_exchange_by_id`(IN`eid`int)
    BEGIN
    #Routinebodygoeshere...
    SET@eid=eid;
    DELETEFROMgk_exchangeWHEREid=@eid;
    END
    DELIMITER;
    代碼如下:
    #通過賬號查詢用戶或者管理員
    ------------------------------
    --Procedurestructurefor`sp_select_user_by_uid`
    ------------------------------
    DROPPROCEDUREIFEXISTS`sp_select_user_by_uid`;
    DELIMITER;;
    CREATEDEFINER=`root`@`localhost`PROCEDURE`sp_select_user_by_uid`(IN`uid`varchar(20),IN`getAdmin`int)
    BEGIN
    #Routinebodygoeshere...
    SET@uid=uid;
    #SET@getadmin=getAdmin;
    #查詢管理員
    IF(getAdmin=1)THEN
    SELECTus.*,un.`name`,se.`name`,jo.`name`,pe.`level`,pe.powerFROMgk_userASus,gk_unitASun,gk_sectionASse,gk_jobtitleASjo,gk_permissionASpeWHEREus.u_id=un.idANDus.s_id=se.idANDus.j_id=jo.idANDus.uid=pe.user_uidANDus.uid=CONVERT(@uidUSINGutf8)COLLATEutf8_unicode_ci;
    ENDIF;
    #查詢用戶
    IF(getAdmin=0)THEN
    SELECTus.*,un.`name`,se.`name`,jo.`name`FROMgk_userASus,gk_unitASun,gk_sectionASse,gk_jobtitleASjoWHEREus.u_id=un.idANDus.s_id=se.idANDus.j_id=jo.idANDus.uid=CONVERT(@uidUSINGutf8)COLLATEutf8_unicode_ci;
    ENDIF;
    END
    DELIMITER;
    #技術(shù)點4:這個存數(shù)過程需要用到控制語句(ifelseelseifwhilelooprepeatleaveiterate)。
    代碼如下:
    IF(getAdmin=1)THEN
    #語句…
    ENDIF;
    #技術(shù)點5:在傳入?yún)?shù)不匹配的情況下報錯(Columncountdoesn'tmatchvaluecountatrow1),這個就是細心問題了,詳細檢查參數(shù)吧。
    #技術(shù)點6:獲取當前時間的函數(shù):NOW()
    #技術(shù)點7:“`”這個符號是反單引號,兩個反單引號夾起來的會被當做變量,一般是在定義字段時遇到關(guān)鍵字沖突的時候會用到。