TRIM([[BOTH | LEADING | TRAILING] 'remstr' FROM] str)LEADING：刪除左側指定字符串。TRAILING：刪除右側指定字符串。BOTH（預設）：刪除兩側指定字符串。remstr，預設刪除空格。ts_back_pic.path 為例）| 需求 | SQL | 說明 |
|---|---|---|
刪除左側 / | SELECT TRIM(LEADING '/' FROM `path`) AS paths FROM `ts_back_pic` LIMIT 10; | 只刪開頭連續的 / |
刪除右側 / | SELECT TRIM(TRAILING '/' FROM `path`) AS paths FROM `ts_back_pic` LIMIT 10; | 只刪結尾連續的 / |
刪除兩側 / | SELECT TRIM(BOTH '/' FROM `path`) AS paths FROM `ts_back_pic` LIMIT 10; | 頭尾皆刪 |
| 刪除兩側空格 | SELECT TRIM(`path`) AS paths FROM `ts_back_pic` LIMIT 10; | 等同 TRIM(BOTH ' ' FROM ...) |
刪除空格 + 換行 \r\n | SELECT TRIM(BOTH '\r\n' FROM TRIM(`path`)) AS paths FROM `ts_back_pic` LIMIT 10; | 巢狀處理多種空白字符 |
trim($str, '/abc') 會刪除字符集合 {/, a, b, c} 中任意字符。TRIM(BOTH '/abc' FROM str) 視 /abc 為**整體字符串**，僅刪除完全匹配的前綴/後綴 /abc。
