How do I remove certain leading characters from text-CodePudding

How do I remove characters =,?, ,- and @ from a text column, but only if they appear as the prefix in a string?

For example:

Input	Output
`#Stackoverflow`	`Stackoverflow`
`@#StackOverflow`	`Stackoverflow`
`=? -Stackoverflow`	`Stackoverflow`

CodePudding user response：

Making the assumption "prefix" means to remove the characters to the left of the first non-special character, but special characters later in the string should remain:

with data as (
    select '@#StackOverflow' string union all 
    select '=? Stack#@Overflow' union all 
    select 'Stack#@Overflow'
)
select * , Stuff(string,1,p.pos-1,'')
from data
cross apply(values(PatIndex('%[^=? -@#]%',string)))p(pos);

Original	Fixed
@#StackOverflow	StackOverflow
=? Stack#@Overflow	Stack#@Overflow
Stack#@Overflow	Stack#@Overflow