asp.net - 如何检查用户名是否存在

Question

如何在用户名存在时返回 1，其他情况下返回 0？这是我尝试过的。

IF EXISTS (SELECT * FROM [User] WHERE UserName = @UserName and EmailID=@EmailID) 
    begin
      return 1;
    end
     else
      begin
    declare @CreatedOn datetime
    select @CreatedOn = getdate()
    insert into [User](UserName,Password,EmailID,ContactNo,CreatedOn) values(@UserName,@Password,@EmailID,@ContactNo,@CreatedOn)

Answer 1

CREATE PROCEDURE CheckUserExists
AS
    @UserName NVARCHAR(MAX),
    @Email NVARCHAR(MAX)
BEGIN    
    IF EXISTS (SELECT 1 FROM [User] WHERE UserName = @UserName OR EmailID=@EmailID) 
    BEGIN
        RETURN 1
    END
    ELSE BEGIN
        RETURN 0    
    END
END