mysql學(xué)習(xí)心得之存儲過程

字號:


    先來看段mysql查詢文章回復(fù)語句:
    代碼如下:
    #查詢文章回復(fù)
    ------------------------------
    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(jìn)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(jìn)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(xì)心問題了,詳細(xì)檢查參數(shù)吧。
    #技術(shù)點6:獲取當(dāng)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(dāng)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。