SQL Server 2017

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create table test(col varchar(100));
insert into test values('mypass@12#');
insert into test values('mypass');
insert into test values('mypass@12#$!');
insert into test values('mypass@12*&&&');
insert into test values('mypass@12######');
5 rows affected

SELECT * from test WHERE (len(COL)- len(REPLACE(REPLACE(REPLACE(REPLACE(REPLACE(
       REPLACE(REPLACE(REPLACE(REPLACE(col,
        '!',''),'@',''),'#',''),'$',''),'%',''),
        '^',''),'&',''),'*',''),' ','')) ) >=5


col


mypass@12*&&&

mypass@12######


Create Function [dbo].[RemoveNonAlphaCharacters](@Temp VarChar(1000))
Returns VarChar(1000)
AS
Begin

    Declare @KeepValues as varchar(50)
    Set @KeepValues = '%[^a-Z0-9]%'
    While PatIndex(@KeepValues, @Temp) > 0
        Set @Temp = Stuff(@Temp, PatIndex(@KeepValues, @Temp), 1, '')

    Return @Temp
End
Select * from test where (len(col) - len(dbo.RemoveNonAlphaCharacters(col))) > =5


col


mypass@12*&&&

mypass@12######