Posted 鐚崄涓夎鎶€鏈?/a>
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馃崁瀛愭煡璇㈣〃杈惧紡鏈夊洓绉嶇被鍨嬶紝鍒嗗埆涓鸿〃鏍煎瓙鏌ヨ(tabular)銆佹煴褰㈠瓙鏌ヨ(columnar)銆佽瀛愭煡璇?row)銆佸拰鏍囬噺瀛愭煡璇?scalar)銆傚叾涓瘮杈冨父鐢ㄧ殑鏄〃鏍笺€佹煴褰㈠拰鏍囬噺銆傝〃鏍煎父鍑虹幇鍦‵ROM瀛愬彞涓€傝€屾煴褰㈠父鍑虹幇鍦↖N鎴栬€匒NY绛夎皳璇嶅悗銆傛爣閲忎綔涓鸿繑鍥炵殑涓€涓崟琛屽崟鍒楃殑鍊煎嚑涔庡彲浠ュ嚭鐜板湪SQL璇彞鐨勪换浣曞湴鏂广€俒鈥
馃崈 1. 瀛愭煡璇?/strong>琛ㄨ揪寮忔湁 馃崈 2. 琛ㄦ牸瀛愭煡璇?/strong>锛氬瓙鏌ヨ杩斿洖涓€寮犺〃锛岃瀛愭煡璇㈠繀椤诲嚭鐜板湪SQL-92涓瀹氱殑浣跨敤浣嶇疆锛屽嵆鍑虹幇鍦?code class="mq-9">FROM瀛愬彞涓€?/p>
馃崈 3. 鏌辩姸瀛愭煡璇?/strong>锛氬瓙鏌ヨ杩斿洖涓€寮犱粎鍖呭惈涓€鍒楃殑琛紝杩欐槸鍘烻QL-86鍜孲QL-89涓殑涓€绉嶉噸瑕佺被鍨嬶紝鍥犱负 馃崈 4. 琛屽瓙鏌ヨ锛氳瀛愭煡璇㈣繑鍥炲崟琛屻€傚湪浣跨敤琛岀殑鍦版柟閮藉彲浠ヤ娇鐢ㄦ绫诲瓙鏌ヨ銆傝繖绉嶅瓙鏌ヨ鏄祵鍏ュ紡SQL涓娇鐢ㄧ殑鍗曚緥SELECT璇彞鐨勫熀纭€銆傝繖绫诲瓙鏌ヨ鐜板湪鐢ㄧ殑骞朵笉澶氥€?/p>
馃崈 5. 鏍囬噺瀛愭煡璇?/strong>锛氭爣閲忓瓙鏌ヨ杩斿洖鍗曚釜鏍囬噺鍊笺€傚畠鍙互鐢ㄥ湪浠讳綍鍙娇鐢ㄦ爣閲忓€肩殑鍦版柟锛屽嵆鍙敤浜嶴ELECT鎴朩HERER瀛愬彞涓€傚鏋滄爣閲忓瓙鏌ヨ杩斿洖绌虹粨鏋滐紝鍒欒浆鎹负NULL銆傚鏋滄爣閲忓瓙鏌ヨ杩斿洖澶氳锛屽皢杩斿洖鍩烘暟杩濊閿欒銆?/p>
馃崅 琛ㄥ瓙鏌ヨ锛氳繑鍥炰竴寮犲琛屽鍒楃殑琛紝鍙互鐞嗚В鍏朵负涓€寮犱竴娆℃€х殑瑙嗗浘銆傛绉嶅瓙鏌ヨ鍑虹幇鍦?code class="mq-18">FROM瀛愬彞涓紝鎵ц鐨勬椂鍊?span> 鑼冧緥 浜у搧锛坧roduct锛夎〃涓殑瀛楁鏈夛細 product_id 浜у搧id ,product_name 浜у搧鍚嶇О ,product_type 浜у搧绫诲瀷 ,sale_price 鍞崠浠锋牸 ,purchase_price 閲囪喘浠锋牸 ,regist_date 娉ㄥ唽鏃ユ湡 鍗曞眰瀛愭煡璇細 瀛愭煡璇綔涓轰复鏃惰〃锛屽彲宓屽澶氬眰瀛愭煡璇細 鍏堟墽琛屾渶鍐呭眰鐨勬煡璇紝浣跨敤鍟嗗搧绫诲瀷鍒嗙粍锛涘啀鎵ц澶栧眰瀛愭煡璇紝鎵惧嚭鍒嗙粍鍟嗗搧鏁伴噺涓?鐨勫晢鍝侊紱鏈€鍚庢墽琛屾渶澶栧眰鐨勫瓙鏌ヨ锛岃緭鍑鸿〃鏁版嵁銆?/p>
馃崅 鏌辩姸瀛愭煡璇?/strong>锛氬瓙鏌ヨ杩斿洖涓€寮犱粎鍖呭惈涓€鍒楃殑琛紝鐢ㄤ簬
鏂版坊鍔犱骇鍝佽鎯咃紙product_info锛夎〃涓殑瀛楁鏈夛細 product_id 浜у搧id ,tags浜у搧鏍囩 ,desc 浜у搧鎻忚堪 鏌ヨ鏈夋弿杩颁俊鎭殑浜у搧锛屼娇鐢ㄥ瓙鏌ヨ鐨?nbsp;in 璋撹瘝瀹炵幇: 鏌ヨ浜у搧浠锋牸澶т簬锛屼换浣曞瓙鏌ヨ鏌ヨ鍑虹殑浠锋牸涔嬩竴鏃㈢鍚堟潯浠讹紝浣跨敤瀛愭煡璇㈢殑 any 璋撹瘝瀹炵幇锛?/p> 馃崅 鏍囬噺瀛愭煡璇?/strong>锛?/p>
杩斿洖涓€寮犱粎鏈夊崟琛屽崟鍒楃殑琛紝鍏惰繑鍥炵殑鏄崟涓€鐨勫€笺€?/p>
鑳藉浣跨敤甯告暟鎴栬€呭垪鍚嶇殑鍦版柟锛屾棤璁烘槸 SELECT 瀛愬彞銆?GROUP BY 瀛愬彞銆?HAVING 瀛愬彞锛岃繕鏄疧RDER BY 瀛愬彞锛屽嚑涔庢墍鏈夌殑鍦版柟閮藉彲浠ヤ娇鐢ㄣ€?/p>
鍒涘缓鏁欏笀琛紝瀛︾敓琛細 鏁欏笀琛?/strong>涓殑瀛楁鏈?nbsp;teacher_name(鏁欏笀鍚嶇О) , birth_date(鐢熸棩) 瀛︾敓琛?/strong>涓殑瀛楁鏈?nbsp;student_name(瀛︾敓鍚嶇О), birth_date(鐢熸棩) 鍒涘缓渚涘簲鍟嗗拰杩愯緭閲忕殑琛?/p> 渚涘簲鍟嗚〃(suppliers)涓瓧娈垫湁: sup_nbr(渚涘簲鍟嗙紪鍙? , sup_name(渚涘簲鍟嗗悕绉?/span>) 杩愯緭閲?span class="mq-62">琛?shipments)涓瓧娈垫湁: sup_nbr(渚涘簲鍟?/span>缂栧彿), onhand_qty(渚涘簲鍟嗕緵璐ч噺) 鏌ユ壘鍝簺浜у搧缁忕悊璐熻矗鐨勮揣鐗╋紝鍦ㄤ粨搴撲腑鐨勫簱瀛樺ぇ浜庡晢搴楄揣鏋?/p> 涓婅堪鏌ヨ锛屽彲浠ュ彇浠ｅ涓嬬殑鑱旀煡 以上是关于的主要内容，如果未能解决你的问题，请参考以下文章鍥涚绫诲瀷锛屽垎鍒负琛ㄦ牸(tabular)銆?code class="mq-5">鏌卞舰(columnar)銆?code class="mq-6">琛?/code>(row)銆佸拰鏍囬噺(scalar)銆?/p>
IN銆?code class="mq-12"><姣旇緝鎿嶄綔绗?gt;ALL鍜?code class="mq-13"><姣旇緝鎿嶄綔绗?gt;{ANY|SOME}璋撹瘝锛屽皢鍗曚釜鍒楄浆鎹㈡垚涓€鍒楃敱AND鎴栬€匫R杩炴帴鐨勬瘮杈冭繍绠楃殑璇█鑳藉姏銆?/p>
1. 琛ㄦ牸瀛愭煡璇?/h1>
鍐呴儴瀛愭煡璇紭鍏堟墽琛?/code>銆?br>馃崅瀛愭煡璇㈡煡璇㈢粨鏋滃彲浠ヤ綔涓轰竴寮犺〃鍜屽埆琛ㄥ叧鑱旀煡璇€?/p>
鍜?code class="mq-34"><姣旇緝鎿嶄綔绗?gt;{ANY|SOME}璋撹瘝
SELECT product_type, cnt_product FROM ( SELECT product_type, COUNT( * ) AS cnt_product FROM Product GROUP BY product_type ) AS ProductSum;
SELECT product_type, cnt_product FROM ( SELECT * FROM ( SELECT product_type, COUNT( * ) AS cnt_product FROM Product GROUP BY product_type ) AS ProductSum WHERE cnt_product = 4 ) AS ProductSum2;
2. 鏌辩姸瀛愭煡璇?/h1>
IN銆?code class="mq-33"><姣旇緝鎿嶄綔绗?gt;ALL
SELECT * FROM product WHERE product_id IN ( SELECT product_id FROM product_info )
SELECT * FROM product WHERE sale_price > ANY ( SELECT sale_price FROM product WHERE sale_price BETWEEN 500 AND 8000 )3. 鏍囬噺瀛愭煡璇?/h1>
馃崅 浣嶇疆锛?/p>
鑼冧緥涓€
WHERE鍚庝腑浣跨敤鐨勬爣閲忓瓙鏌ヨ锛屾煡璇㈡瘮鏈€澶у鐢熷勾榫勫ぇ5宀佺殑鎵€鏈夋暀甯?/p>
SELECT t1.teacher_name FROM teachers t1 WHERE t1.birth_date < ( SELECT MIN( s1.birth_date ) - INTERVAL 5 YEAR FROM students s1 )鑼冧緥浜?/h6>
鍏宠仈瀛愭煡璇?/code>浣跨敤鏍囬噺瀛愭煡璇紝鏌ヨ鍝簺渚涘簲鍟嗙粰鎴戜滑鎻愪緵浜嗕笉鍒?00鐨勮揣鐗?/p>
SELECT sup_nbr, sup_name FROM suppliers WHERE 100 > ( SELECT SUM( onhand_qty ) FROM shipments WHERE shipments.sup_nbr = suppliers.sup_nbr )鑼冧緥涓?/h6>
SELECT manager_name, product_nbr FROM stores AS s1WHERE ( SELECT SUM( onhand_qty ) FROM warehouses AS w1 WHERE s1.product_nbr = w1.product_nbr ) < ( SELECT SUM( shelf_qty ) FROM retailstores AS r1 WHERE s1.product_nbr = r1.product_nbr );鑼冧緥鍥?/h6>
杩斿洖鍒?/code>涓娇鐢ㄥ瓙鏌ヨ锛屾煡璇㈡瘡涓緵搴斿晢鐨勮鍗曟暟閲?/p>
SELECT sup_id, sup_name, ( SELECT COUNT( * ) FROM orders WHERE suppliers.sup_id = orders.sup_id ) AS order_countFROM suppliers;
SELECT sup_id, sup_name, COUNT( * ) FROM suppliers LEFT JOIN orders ON suppliers.sup_id = orders.sup_idGROUP BY suppliers.sup_id;