In LinqPad using LinqKit, I'm doing the following:
var topPredicate = PredicateBuilder.True<LandRecord>();
topPredicate = topPredicate.And(a=>a.InstrumentType == "DEED");
topPredicate = topPredicate.And(a=>a.BookType == "OFFICIAL RECORD");
var subPredicate = PredicateBuilder.True<LandRecord>();
subPredicate = subPredicate.And(a=>a.Parties.Any(b=>b.LastName == "SMITH"));
subPredicate = subPredicate.And(a=>a.Parties.Any(b=>b.FirstName == "John"));
LandRecords.AsExpandable().Include(a=>a.Parties).Where(topPredicate).Where(subPredicate).ToList();
This is the SQL that it is creating:
SELECT
[Extent1].[LandRecordID] AS [LandRecordID],
[Extent1].[DocumentID] AS [DocumentID],
[Extent1].[InstrumentNo] AS [InstrumentNo],
[Extent1].[BookType] AS [BookType],
[Extent1].[BookNo] AS [BookNo],
[Extent1].[PageNo] AS [PageNo],
[Extent1].[DateFiled] AS [DateFiled],
[Extent1].[DateInstrument] AS [DateInstrument],
[Extent1].[InstrumentType] AS [InstrumentType],
[Extent1].[MortgageAmount] AS [MortgageAmount]
FROM [LAND].[LandRecord] AS [Extent1]
WHERE (N'DEED' = [Extent1].[InstrumentType]) AND (N'OFFICIAL RECORD' = [Extent1].[BookType]) AND ( EXISTS (SELECT
1 AS [C1]
FROM [LAND].[Party] AS [Extent2]
WHERE ([Extent1].[LandRecordID] = [Extent2].[LandRecordID]) AND (N'SMITH' = [Extent2].[LastName])
)) AND ( EXISTS (SELECT
1 AS [C1]
FROM [LAND].[Party] AS [Extent3]
WHERE ([Extent1].[LandRecordID] = [Extent3].[LandRecordID]) AND (N'John' = [Extent3].[FirstName])
))
The SQL that I would like to have it create would be the following where both LastName and FirstName would be combined / joined in the same exists statement.
In production, that sub query could contain 1 or more conditions with each being a startswith, endswith, contains, or exact match. So I need to be able to manually build that sub query 1 piece at a time.
SELECT
[Extent1].[LandRecordID] AS [LandRecordID],
[Extent1].[DocumentID] AS [DocumentID],
[Extent1].[InstrumentNo] AS [InstrumentNo],
[Extent1].[BookType] AS [BookType],
[Extent1].[BookNo] AS [BookNo],
[Extent1].[PageNo] AS [PageNo],
[Extent1].[DateFiled] AS [DateFiled],
[Extent1].[DateInstrument] AS [DateInstrument],
[Extent1].[InstrumentType] AS [InstrumentType],
[Extent1].[MortgageAmount] AS [MortgageAmount]
FROM [LAND].[LandRecord] AS [Extent1]
WHERE (N'DEED' = [Extent1].[InstrumentType]) AND (N'OFFICIAL RECORD' = [Extent1].[BookType]) AND ( EXISTS (SELECT
1 AS [C1]
FROM [LAND].[Party] AS [Extent2]
WHERE ([Extent1].[LandRecordID] = [Extent2].[LandRecordID]) AND (N'SMITH' = [Extent2].[LastName] AND (N'John' = [Extent2].[FirstName])
))
You can build the sub predicate separately and add it to the top predicate if it contains anything:
var topPredicate = PredicateBuilder.True<LandRecord>();
topPredicate = topPredicate.And(a=>a.InstrumentType == "DEED");
topPredicate = topPredicate.And(a=>a.BookType == "OFFICIAL RECORD");
var subPredicate = PredicateBuilder.True<Party>();
if (!string.IsNullOrWhiteSpace(firstName)
{
subPredicate = subPredicate.And(b => b.FirstName == firstName);
}
if (!string.IsNullOrWhiteSpace(lastName)
{
subPredicate = subPredicate.And(b => b.LastName == lastName);
}
// If the subPredicate's body is still just PredicateBuilder.True<Party>(), ignore it.
if (!(subPredicate.Body is ConstantExpression))
{
topPredicate = topPredicate.And(lr => lr.Parties.AsQueryable().Any(subPredicate));
}
Here, lr.Parties.AsQueryable()
is used because Parties
is probably an ICollection
, ie IEnumerable
. As IEnumerable.Any
accepts a Func
, not an Expression
, the code wouldn't compile without AsQueryable()
.
By the way, my code doesn't contain AsExpandable()
because I use Universal PredicateBuilder .
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