我们正在使用Amazon-Redshift（符合PostgreSQL的语法），我们在表格中有以下字符串
"TOTO;"
"TOTO;;"
"TOTO;;;"
"TOTO;;;;"
我想＆＃39; rtrim＆＃39;双分号。所以我想
"TOTO;"
"TOTO"
"TOTO;"
"TOTO"
怎么做？
答案 0 :(得分：2)
public extension UIColor {
convenience init?(hex: String) {
var red: CGFloat = 0.0
var green: CGFloat = 0.0
var blue: CGFloat = 0.0
var alpha: CGFloat = 1.0
let hex = hex.replacingOccurrences(of: "^#", with: "", options: .regularExpression)
guard let hexValue = UInt64(hex, radix: 16) else {
print("invalid hex string")
return nil
}
switch (hex.count) {
case 3:
red = CGFloat((hexValue & 0xF00) >> 8) / 15.0
green = CGFloat((hexValue & 0x0F0) >> 4) / 15.0
blue = CGFloat(hexValue & 0x00F) / 15.0
case 4:
red = CGFloat((hexValue & 0xF000) >> 12) / 15.0
green = CGFloat((hexValue & 0x0F00) >> 8) / 15.0
blue = CGFloat((hexValue & 0x00F0) >> 4) / 15.0
alpha = CGFloat(hexValue & 0x000F) / 15.0
case 6:
red = CGFloat((hexValue & 0xFF0000) >> 16) / 255.0
green = CGFloat((hexValue & 0x00FF00) >> 8) / 255.0
blue = CGFloat(hexValue & 0x0000FF) / 255.0
case 8:
red = CGFloat((hexValue & 0xFF000000) >> 24) / 255.0
green = CGFloat((hexValue & 0x00FF0000) >> 16) / 255.0
blue = CGFloat((hexValue & 0x0000FF00) >> 8) / 255.0
alpha = CGFloat(hexValue & 0x000000FF) / 255.0
default:
print("Invalid RGB string, number of characters after '#' should be either 3, 4, 6 or 8", terminator: "")
return nil
}
self.init(red: red, green: green, blue: blue, alpha: alpha)
}
}
函数与regexp_replace正则表达式（任意数量的(;;)*$后跟行尾）：
;;答案 1 :(得分：0)
select replace('TODO;;;',';;','')
如果我做了一个错误的假设请发表评论，我会重新调整我的答案。