sql-server - SQL Server rtrim ltrim and charindex

Question

I have the following scenario John Doe johndoe@email.com john johndoe@email.com

I want away that I can detect the first right space and just exclude everything to the left so I just get the email address of the person. So: John Doe johndoe@email.com should be johndoe@email.com john johndoe@email.com should be johndoe@email.com

This is what i have

Declare @test varchar(50)
Select @test = 'John Doe johndoe@email.com'
SELECT Right(@test, CHARINDEX(' ', @test))

This is only giving me the email.com!

Thank you.

Answer 1

Declare @test varchar(50)
Select @test = 'John Doe johndoe@email.com'
SELECT RIGHT(@test, CHARINDEX(' ', REVERSE(@test)-1))

或更安全的方法（如果有没有空格分隔符的字符串）：

Declare @test varchar(50)
Select @test = 'johndoe@email.com'
SELECT 
    CASE 
        WHEN CHARINDEX(' ', REVERSE(@test)) > 0 THEN RIGHT(@test, CHARINDEX(' ', REVERSE(@test))-1)
        ELSE @test
    END

Answer 2

CharIndex 返回 5，这是测试字符串中第一个空格的位置，位于“John”和“Doe”之间。

因此，Right 返回测试字符串最右边的 5 个字符，即“l.com”

Answer 3

嗨，你也可以试试rtrim

Declare @test varchar(50)
Select @test = 'John Doe johndoe@email.com'
SELECT RIGHT(@test, CHARINDEX(' ', REVERSE(rtrim(@test))))