mysql灏嗗瓧绗︿覆杞垚鏁板瓧

Posted 2020-12-21

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闇€瑕佸厛杞崲鎴愭暟瀛楀啀杩涜鎺掑簭

1.鐩存帴鐢ㄥ姞娉?/p>

銆€銆€瀛楃涓?0

eg:

銆€銆€select * from orders order by (mark+0)  desc

eg:

浠ュ垎绫诲瓧娈佃繘琛屽垎缁勶紝鑾峰彇鍒嗙被鎬绘暟amount锛屽拰qty锛堟暟閲忥級锛屾渶鍚庝互amount杩涜鏈夊ぇ鍒板皬鐨勫€掑簭鎺掑垪

SELECT category_code,SUM(transaction_number) as qty ,FORMAT(SUM(number*price),2)+0 as amount FROM sell WHERE date=鈥?017-03-06鈥?nbsp;GROUP BY category_code ORDER BY amount DESC;

2.浣跨敤鍑芥暟

CAST(value as type);

CONVERT(value, type);

娉細

銆€銆€杩欓噷鐨則ype鍙互涓猴細

銆€銆€銆€銆€娴偣鏁?: DECIMAL 
銆€銆€銆€銆€鏁存暟 : SIGNED
銆€銆€銆€銆€鏃犵鍙锋暣鏁?: UNSIGNED 

eg:

銆€銆€select * from orders order by CONVERT(mark,SIGNED)  desc

銆€銆€select * from orders order by CAST(mark as SIGNED)  desc