括号中两个条件都为真的SQL

Question

SELECT
    *
FROM 
    TableName
WHERE
    Column1 = 'X'
    AND Column2 = 'Y'
    AND (Column3 != 'D' AND Column4 != 'D') -- Want to apply this filter ONLY if both conditions are true

如何编写第三个过滤器，以便仅在两个都为真时才应用。目前，方括号没有什么区别，但我需要在方括号中表达以将其视为单个条件

例：

Column1     Column2     Column3     Column4
X           Y           D           L   
X           Y           L           L   
X           Y           L           D   
X           Y           D           D   -- want to remove this line

结果应为：

Column1     Column2     Column3     Column4
X           Y           D           L   
X           Y           L           L   
X           Y           L           D   

Answer 1

SELECT
    *
FROM 
    TableName
WHERE
    Column1 = 'X'
    AND Column2 = 'Y'
    AND NOT (Column3 = 'D' AND Column4 = 'D')