基于Expression Lambda表达式树的通用复杂动态查询构建器——《摘要篇》

Field_A =1 and Field_B =2 Or Field_C=3 
--或者 
Field_A =1 and （Field_B =2 Or Field_C=3）

{ "Name" : "id", "Op" : "=", "Value" : 1 }

Id=1 and name="MyName"

 [ 
     {
      "lg" : "",
      	"Predicates" : {"Name" : "id", "Op" : "=", "Value" : 1 }
     },
     {
        "lg":"and",
      	"Predicates": { "Name" : "Name", "Op" : "=", "Value" : "MyName"}
     } 
 ] 

Id>1 and Id<10 and (Name="MyName" or Name="HisName")

{
    "lg": "", 
    "filters":
    [ 
        { 
            "lg": "", 
            "Predicates":[ { "lg": "", "Name": "id", "Op": ">", "Value": 1 } ]
         }, 
         { 
            "lg": "and", 
            "Predicates":[ { "lg": "", "Name": "id", "Op": "<", "Value": 10 } ] 
         },
         {
            "lg": "and",
            "Predicates":
            [
                {"lg": "","Name": "name",  "Op": "=", "Value": "MyName"},         
                {"lg": "or","Name": "name","Op": "=","Value": "HisName"}
            ]
        }
    ]
}

--更复杂一点的等等：
Id=1 
 and (
     (Name="MyName" or Name="HisName") or (Phone like"13899%" and Emil Like "%@xx.com")
 )

Query.Where(QueryFilterBuilder.CreateFilterExpression<Entity>(conditionBlock));

where 
    ( 
        (            
            (A.Field_A + A.Field_B) / A.Field_C=(2+3) % 2 or A.Field_A= A.Field_C
			or (A.Field_C > 2 and Len(A.Field_D) < 2)
        ) 
        and (A.Field_E Like"%xxooxx" or A.Field_F in (1,2,3))
    ) 
    and A.Field_G in (select B.Field_N From B where cast(B.Fieild_DatetimeString as Datetime) = A.FieldDatetime)
)