c# - Using the logic from one lambda within a second lambda -

i've looked @ other questions around , can't work out how apply answers particular situation. have couple of models this:

public class person {     public int personid { get; set; } }  public class business {     public int businessid { get; set; } } 

i want able write couple of different generic methods: 1 gets models using provided lambda might this:

getwhere(p => p.personid == 1) 

and 1 models using unique key - make flexible, i'd able specify unique key using lambda:

getbyuniquekey(p => p.personid, 1) 

or

getbyuniquekey(b => b.businessid, 1) 

ideally getbyuniquekey shorthand method build expression send getwhere, , return firstordefault() result. logic escaping me. want do:

public ienumerable<tmodel> getwhere(expression<func<tmodel, bool>> whereexpression) {     // db using expression provided }  public tmodel getbyuniquekey<tuniquekey>(          expression<func<tmodel, tuniquekey>> uniquekeyproperty,          tuniquekey value) {     return getwhere(m => uniquekeyproperty(m) == value).firstordefault(); } 

so want take uniquekeyproperty expression, invoke on supplied parameter somehow property, , use property in whereexpression expression.

a note on duplicate questions: know looks duplicate of other similar questions, please note have read , can't figure out how apply answers specific use case.

some clarification in response comments:

put simply, want following:

i want take expression p => p.personid , value 1, , generate whereexpression looks p => p.personid == 1. (thanks @rob)

you can build new expression key selector , value provided so:

public tmodel getbyuniquekey<tuniquekey>(     expression<func<tmodel, tuniquekey>> uniquekeyselector,     tuniquekey value) {     return getwhere(expression.lambda<func<tmodel,bool>>(         expression.makebinary(             expressiontype.equal,             uniquekeyselector.body,             expression.constant(value, typeof(tuniquekey))),         uniquekeyselector.parameters)); } 

for querying id wouldn't bother approach. check out other static methods on expression class.