鏈夋病鏈夎SQL鎶ラ敊鎼炲緱鎯崇牳閿洏锛熺壒鍒槸褰撲綘鍦ㄦ繁澶滃姞鐝鍏ユ暟鎹椂锛岀獊鐒惰烦鍑烘潵鐨勭孩鑹查敊璇彁绀猴紝绠€鐩存瘮鎭愭€栫墖杩樺悡浜猴紒涓婂懆鎴戜滑閮ㄩ棬鏂版潵鐨勫疄涔犵敓锛屽氨鍥犱负涓婚敭鍐茬獊鎶?00鏉¤鍗曟暟鎹悶鐮镐簡...鍒厡锛屼粖澶╁甫浣犺鎷涙媶鎷涳紒

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鍦烘櫙杩樺師锛氫綘鑲畾閬囧埌杩囪繖绉嶆姄鐙傛椂鍒?/h3>

sql澶嶅埗
INSERT INTO orders (order_id, product_name) 
VALUES (1001, '鏅鸿兘鎵嬭〃');
-- 鐒跺悗绯荤粺鏃犳儏鎻愮ず锛?/span>
-- Error Code: 1062. Duplicate entry '1001' for key 'PRIMARY'

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馃攳鎺掓煡涓夋澘鏂э紙闄勭湡瀹炴渚嬶級

1. 鈥?strong>鈥嬫煡鐜板瓨鏁版嵁鈥?/strong>鈥?/li>

sql澶嶅埗
SELECT * FROM orders WHERE order_id=1001;

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1. 鈥?strong>鈥嬭嚜澧炰富閿殑鍧戔€?/strong>鈥?br/> 鍚屼簨鑰佺帇鏇炬妸鑷涓婚敭鎵嬪姩璁惧€硷紝缁撴灉瀵艰嚧鍚庣画鎻掑叆鍏ㄦ姤閿欍€傝寰楃敤锛?/li>

sql澶嶅埗
ALTER TABLE orders AUTO_INCREMENT=2000;

1. 鈥?strong>鈥嬩复鏃舵晳鍛芥嫑鈥?/strong>鈥?br/> 鎬ョ潃瑕佹暟鎹厛鍏ュ簱锛熷彲浠ユ殏鏃剁鐢ㄧ害鏉燂細

sql澶嶅埗
SET FOREIGN_KEY_CHECKS=0;
-- 鎵ц浣犵殑鎻掑叆鎿嶄綔
SET FOREIGN_KEY_CHECKS=1; 

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鏂规硶瀵规瘮琛?/h3>

澶勭悊鏂瑰紡	閫傜敤鍦烘櫙	椋庨櫓鎸囨暟
鍒犻櫎閲嶅璁板綍	鏄庣‘鏄剰鏁版嵁鏃?/td>	馃挘馃挘馃挘
淇敼鎻掑叆鍊?/td>	娴嬭瘯鐜璋冭瘯	馃挘
璋冩暣鑷璧峰鍊?/td>	鎵归噺杩佺Щ鏁版嵁	馃挘馃挘
涓存椂绂佺敤绾︽潫	绱ф€ョ敓浜х幆澧冧慨澶?/td>	馃挘馃挘馃挘馃挘

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馃挕绗簩鍏筹細瀛楁绫诲瀷閿欒鈥斺€斿綋鏁板瓧閬囧埌鏂囧瓧闄烽槺

甯歌杞︾ジ鐜板満

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• 鏃ユ湡鏍煎紡鏀鹃鑷垜 鈫?'2024骞?鏈?鏃? vs '2024-05-01'
• 鏁板€煎甫鐗规畩绗﹀彿 鈫?'1,000'鎯宠繘DECIMAL瀛楁

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馃洜锔忎竾鑳借浆鎹㈠叕寮?/h3>

sql澶嶅埗
-- 澶勭悊甯﹂€楀彿鐨勬暟瀛?/span>
INSERT INTO sales (amount)
VALUES (REPLACE('1,234.56', ',', ''));

-- 杞崲涓枃鏃ユ湡
STR_TO_DATE('2024骞?鏈?鏃?, '%Y骞?m鏈?d鏃?);

-- 澶勭悊瓒呴暱鏂囨湰
SUBSTRING('杩欐槸涓€娈佃秴闀跨殑闇€瑕佹埅鏂殑鏂囨湰', 1, 255);

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绫诲瀷鍖归厤閫熸煡鍗?/h3>

瀛楁绫诲瀷	姝ｇ‘绀鸿寖	浣滄绀鸿寖
INT	18	'鍗佸叓宀?
DATETIME	'2024-05-01 09:00'	'浜斾竴鍔冲姩鑺備笂鍗?
DECIMAL(10,2)	99.99	涔濆崄涔濆潡涔濇瘺涔?/td>
VARCHAR(20)	'涓浗'	甯?0涓瓧鐨勮秴闀垮湴鍧€

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馃鐏甸瓊鎷烽棶鐜妭

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鈥?strong>鈥婹锛氬鍏xcel鎬绘姤绫诲瀷閿欒鎬庝箞鍔烇紵鈥?/strong>鈥?br/> A锛氬厛鍦‥xcel閲屽仛鏁版嵁娓呮礂锛氱敤=ISTEXT(A1)妫€鏌ュ瓧娈电被鍨嬶紝鐢?code>TEXT()鍑芥暟缁熶竴鏍煎紡銆?/p>

鈥?strong>鈥婹锛氭祴璇曟暟鎹椂鎬曟悶鍧忕敓浜у簱锛熲€?/strong>鈥?br/> A锛氱敤杩欎釜淇濆懡鍛戒护鍒涘缓涓存椂娌欑洅锛?/p>

sql澶嶅埗
CREATE TABLE temp_table LIKE real_table;
INSERT INTO temp_table SELECT * FROM real_table LIMIT 0;

馃懆馃捇鐙鏁版嵁鎻

鏍规嵁Stack Overflow 2023鏁版嵁搴撻敊璇粺璁★細

• 涓婚敭鍐茬獊鍗犳墍鏈夋彃鍏ラ敊璇殑37%
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