SQL 常用字串處理語法說明
SQL 語法雜碎 - 字串處理 SQL 常用字串處理語法說明：包含 substring、left、right、upper、lower、ltrim、rtrim、、、 取字串中部分字元 SELECT Mem_ID, substring(Mem_ID,4,6) AS MEM_ID_6 FROM members 語法：substring(欄位, 起始字元, 取幾字元) ex: A123456789 => substring(Id,4,6) => 456789 取左側字元 SELECT LEFT(engname,5) FROM members 語法：left(欄位, 位數) ex: SELECT LEFT('abcdefghijk',5) => abcde 取右側字元 SELECT RIGHT(engname,5) FROM members 語法：right(欄位, 位數) ex: SELECT RIGHT('abcdefghijk',5) => ghijk 字串大小寫轉換 upper、lower SELECT upper(engname) FROM members 語法：upper(欄位） ex: michael => upper => MICHAEL SELECT lower(engname) FROM members 語法：lower(欄位） ex: MICHAEL => lower => michael 去除無謂空白 ltrim、rtrim SELECT LTRIM(email) FROM members 語法：ltrim(欄位) ex: " abd@com" => ltrim => "abd@com" SELECT RTRIM(memo) FROM members 語法：rtrim(欄位) ex:"Have a nice day. " => rtrim =>"Have a nice day." 取除特定字串及刪除右邊字串 語法：replace(欄位 COLLATE Chinese_Taiwan_Strok