我如何解析布尔逻辑？

Question

我需要编写一个布尔逻辑解析器,它将布尔逻辑语言转换为SQL WHERE子句.

操作数的顺序始终是正确的顺序(右边的值).

这是一个相对简单的例子.可能有嵌套括号和NOT运算符等的使用.

(CACOUNT=01 OR CACOUNT=02 OR CACOUNT=03)
 AND Q4=1 AND NAME=TIMOTHY

这是WHERE子句类似的内容.

WHERE (
     EXISTS (
       SELECT 1 FROM MyVerticalTable b
       WHERE b.Key=a.Key AND b.Key='CACOUNT' AND b.Value='01'
     )
  OR EXISTS (
       SELECT 1 FROM MyVerticalTable b
       WHERE b.Key=a.Key AND b.Key='CACOUNT' AND b.Value='02'
  )
  OR EXISTS (
       SELECT 1 FROM MyVerticalTable b
       WHERE b.Key=a.Key AND b.Key='CACOUNT' AND b.Value='03'
  )
)
AND EXISTS (
       SELECT 1 FROM MyVerticalTable b
       WHERE b.Key=a.Key AND b.Key='Q4' AND b.Value='1'
)
AND EXISTS (
       SELECT 1 FROM MyVerticalTable b
       WHERE b.Key=a.Key AND b.Key='NAME' AND b.Value='TIMOTHY'
)

Answer 1

好吧，WHERE 之后是布尔表达式，所以你需要通过简单的替换进行翻译，而不是解析。对于您的示例，您只需将引号放在末尾：NAME='TIMOTHY'