Table-value functions in BLToolkit - linq

Question

Is it possible to use SQL Server table-value functions by using the BLToolkit library?
I would like to use it within the Linq query, but I couldn't find anything regarding this on the library wiki.

Answer 1

Define your function in your data context class as the following:
[TableFunction(Name="GetParentByID")]
public Table<Parent> GetParentByID(int? id)
{
return GetTable<Parent>(this, (MethodInfo)MethodBase.GetCurrentMethod(), id);
}
Usage:
[Test]
public void Func2()
{
using (var db = new TestDbManager())
{
var q =
from c in db.Child
from p in db.GetParentByID(2)
select p;
q.ToList();
}
}
SQL:
SELECT
[t2].[ParentID],
[t2].[Value1]
FROM
[Child] [t1], [GetParentByID](2) [t2]
Also you can define it outside of the data context:
public class Functions
{
private readonly IDataContext _ctx;
public Functions(IDataContext ctx)
{
_ctx = ctx;
}
[TableFunction]
public Table<Parent> GetParentByID(int? id)
{
return _ctx.GetTable<Parent>(this, (MethodInfo)(MethodBase.GetCurrentMethod()), id);
}
[TableExpression("{0} {1} WITH (TABLOCK)")]
public Table<T> WithTabLock<T>()
where T : class
{
return _ctx.GetTable<T>(this, ((MethodInfo)(MethodBase.GetCurrentMethod())).MakeGenericMethod(typeof(T)));
}
}
[Test]
public void Func1()
{
using (var db = new TestDbManager())
{
var q =
from p in new Functions(db).GetParentByID(1)
select p;
q.ToList();
}
}
[Test]
public void WithTabLock()
{
using (var db = new TestDbManager())
{
var q =
from p in new Functions(db).WithTabLock<Parent>()
select p;
q.ToList();
}
}
SQL:
SELECT
[p].[ParentID],
[p].[Value1]
FROM
[GetParentByID](1) [p]
SELECT
[p].[ParentID],
[p].[Value1]
FROM
[Parent] [p] WITH (TABLOCK)