娴呰皥瀛樺偍杩囩▼

Posted 2020-08-05

鏍囩锛?/p>

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鍦ㄦ垜鐪嬫潵锛?瀛樺偍杩囩▼灏辨槸鏈変笟鍔￠€昏緫鍜屾祦绋嬬殑闆嗗悎锛?鍙互鍦ㄥ瓨鍌ㄨ繃绋嬩腑鍒涘缓琛紝鏇存柊鏁版嵁锛?鍒犻櫎绛夌瓑銆?/p>

銆€銆€涓轰粈涔堣浣跨敤瀛樺偍杩囩▼?

1. 1. 銆€銆€閫氳繃鎶婂鐞嗗皝瑁呭湪瀹规槗浣跨敤鐨勫崟鍏冧腑锛岀畝鍖栧鏉傜殑鎿嶄綔锛堟濡傚墠闈緥瀛愭墍杩帮級銆?/p>

   2. 銆€銆€鐢变簬涓嶈姹傚弽澶嶅缓绔嬩竴绯诲垪澶勭悊姝ラ锛岃繖淇濊瘉浜嗘暟鎹殑瀹屾暣鎬с€傚鏋滄墍鏈夊紑鍙戜汉鍛樺拰搴旂敤绋嬪簭閮戒娇鐢ㄥ悓涓€锛堣瘯楠屽拰娴嬭瘯锛夊瓨鍌ㄨ繃绋嬶紝鍒欐墍浣跨敤鐨勪唬鐮侀兘鏄浉鍚岀殑銆傝繖涓€鐐圭殑寤朵几灏辨槸闃叉閿欒銆傞渶         瑕佹墽琛岀殑姝ラ瓒婂锛屽嚭閿欑殑鍙兘鎬у氨瓒婂ぇ銆傞槻姝㈤敊璇繚璇佷簡鏁版嵁鐨勪竴鑷存€с€?/p>

   3. 銆€銆€绠€鍖栧鍙樺姩鐨勭鐞嗐€傚鏋滆〃鍚嶃€佸垪鍚嶆垨涓氬姟閫昏緫锛堟垨鍒殑鍐呭锛夋湁鍙樺寲锛屽彧闇€瑕佹洿鏀瑰瓨鍌ㄨ繃绋嬬殑浠ｇ爜銆備娇鐢ㄥ畠鐨勪汉鍛樼敋鑷充笉闇€瑕佺煡閬撹繖浜涘彉鍖栥€?/p>

銆€銆€涓€涓畝鍗曠殑瀛樺偍杩囩▼

create procedure porcedureName ()
begin
    select name from user;
end;

銆€銆€瀛樺偍杩囩▼鐢╟reate procedure 鍒涘缓锛?涓氬姟閫昏緫鍜宻ql鍐欏湪begin鍜宔nd涔嬮棿銆俶ysql涓彲鐢╟all porcedureName ();鏉ヨ皟鐢ㄨ繃绋嬨€?/p>

-- 璋冪敤杩囩▼
call porcedureName ();

銆€銆€璇ュ瓨鍌ㄨ繃绋嬫病鏈夊弬鏁帮紝 鍙槸鍦ㄨ皟鐢ㄧ殑鏃跺€欐煡璇簡鐢ㄦ埛琛ㄧ殑鐢ㄦ埛鍚嶈€屽凡銆?/p>

銆€銆€鍒犻櫎瀛樺偍杩囩▼

DROP PROCEDURE IF EXISTS porcedureName; -- 娌℃湁鎷彿()

銆€銆€浣跨敤鍙傛暟鐨勫瓨鍌ㄨ繃绋?/strong>

create procedure procedureName(
    out min decimal(8,2),
    out avg decimal(8,2),
    out max decimal(8,2)
)
BEGIN
    select MIN(price) INTO min from order;
    select AVG(price) into avg from order;
    select MAX(price) into max from order;
END;

銆€銆€姝よ繃绋嬫帴鍙椾笁涓弬鏁帮紝 鍒嗗埆鐢ㄤ簬鑾峰彇璁㈠崟琛ㄧ殑鏈€灏忋€佸钩鍧囥€佹渶澶т环鏍笺€傛瘡涓弬鏁板繀椤诲叿鏈夋寚瀹氱殑绫诲瀷锛岃繖閲屼娇鐢ㄥ崄杩涘埗鍊硷紙decimal(8,2)锛夛紝 鍏抽敭瀛桹UT鎸囧嚭鐩稿簲鐨勫弬鏁扮敤鏉ヤ粠瀛樺偍杩囩▼浼犲嚭涓€涓€硷紙杩斿洖缁欒皟鐢ㄨ€咃級

銆€銆€MySQL鏀寔IN锛堜紶閫掔粰瀛樺偍杩囩▼锛夈€丱UT锛堜粠瀛樺偍杩囩▼浼犲嚭锛屽杩欓噷鎵€鐢級鍜孖NOUT锛堝瀛樺偍杩囩▼浼犲叆鍜屼紶鍑猴級绫诲瀷鐨勫弬鏁般€傚瓨鍌ㄨ繃绋嬬殑浠ｇ爜浣嶄簬BEGIN鍜孍ND璇彞鍐咃紝濡傚墠鎵€瑙侊紝瀹冧滑鏄竴绯诲垪SELECT璇彞锛岀敤鏉ユ绱㈠€硷紝鐒跺悗淇濆瓨鍒扮浉搴旂殑鍙橀噺锛堥€氳繃鎸囧畾INTO鍏抽敭瀛楋級

銆€銆€涓鸿皟鐢ㄦ淇敼杩囩殑瀛樺偍杩囩▼锛屽繀椤绘寚瀹?涓彉閲忓悕锛屽涓嬫墍绀猴細(鎵€鏈塎ySQL鍙橀噺閮藉繀椤讳互@寮€濮嬨€?

-- 鐢变簬杩囩▼鎸囧畾涓変釜鍙傛暟锛?鏁呰皟鐢ㄥ繀椤昏鍙傛暟鍖归厤
call procedureName(@min, @avg, @max);

銆€銆€璇ヨ皟鐢ㄥ苟娌℃湁浠讳綍杈撳嚭锛?鍙槸鎶婅皟鐢ㄧ殑缁撴灉璧嬬粰浜嗚皟鐢ㄦ椂浼犲叆鐨勫彉閲忥紙@min, @avg, @max锛夈€傜劧鍚庡嵆鍙皟鐢ㄦ樉绀鸿鍙橀噺鐨勫€笺€?/p>

select @min, @avg, @max;

銆€銆€浣跨敤 in 鍙傛暟, 杈撳叆涓€涓敤鎴穒d锛?杩斿洖璇ョ敤鎴锋墍鏈夎鍗曠殑鎬讳环鏍笺€?/p>

create procedure getTotalById (
    in userId int,
    out total decimal(8,2)
)
BEGIN
    select SUM(r.price) from order r
    where r.u_id = userId
    into total;
END;

銆€銆€璋冪敤瀛樺偍杩囩▼

call getTotalById(1, @total);
select @total;

銆€銆€缁撴灉灏嗚繑鍥炶鐢ㄦ埛鎵€鏈夎鍗曠殑鍚堣浠锋牸銆?/p>

銆€銆€澶嶆潅涓€鐐圭殑杩囩▼锛?鏍规嵁鐢ㄦ埛id鑾峰彇璇ョ敤鎴风殑鎵€鏈夎鍗曚环鏍硷紝 骞跺姩鎬佺殑閫夋嫨鏄惁鍔犵◣銆備唬鐮佽璁″涓?/p>

create procedure getTotalByUser2(
    in userId int,
    in falg boolean, -- 鏄惁鍔犵◣鏍囪
    out total decimal(8,2)
)
begin
    DECLARE tmptotal DECIMAL(8,2);
    DECLARE taxrate int DEFAULT 6;-- 榛樿鐨勫姞绋庣殑鍒╃巼
    
    select SUM(r.price) from order r
    where r.u_id = userId
    into tmptotal;
    
    if taxable then
        select tmptotal + (tmptotal/1000*taxrate) into tmptotal;
    end if;
    
    select tmptotal into total;
END;

銆€銆€璇ヨ繃绋嬩紶鍏ヤ笁涓弬鏁帮紝 鐢ㄦ埛id锛?鏄惁鍔犵◣浠ュ強杩斿洖鐨勬€讳环鏍硷紝鍦ㄨ繃绋嬪唴閮紝 瀹氫箟涓や釜灞€閮ㄥ彉閲弔mptotal鍜宼axrate锛屾妸鏌ヨ鍑烘潵鐨勭粨鏋滆祴缁欎复鏃跺彉閲忥紝 鍦ㄥ垽鏂槸鍚﹀姞绋庛€傛渶鍚庢妸灞€閮ㄥ彉閲忕殑鍊艰祴缁欒緭鍑哄弬鏁般€?/p>

call getTotalByUser2(1, false, @total); -- 涓嶅姞绋?/span>
call getTotalByUser2(1, true, @total);  -- 鍔犵◣
select @total;

 

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