I have a linq syntax is used to search database as follows:

 a=& gt; A.t dIsDelete!=true & amp; & A.u Status & gt;=0 & amp; & ((a.u LoginName!=null & amp; & A.u LoginName. The Contains (key)) | | (a.u RealName!=null & amp; & A.u RealName. The Contains (key))) 

Among them, (uLoginName) and (uRealName) is currently the or, but I hope to parameters according to the user to query,

Variables such as: [bLoginName=true] and [variables bRealName=false], only confirm whether uLoginName contain key, and don't care whether uRealName has contains,

This time I hope linq syntax is as follows:

 a=& gt; A.t dIsDelete!=true & amp; & A.u Status & gt;=0 & amp; & ((a.u LoginName!=null & amp; & A.u LoginName. The Contains (key))) 

But can you tell me how to do? Thank you,