/// <summary>
/// Applies the minimal transformations required before parametrization,
/// expression key computing and parsing.
/// </summary>
/// <param name="expression">The expression to transform.</param>
/// <param name="parameters">The parameters used in the transformation process.</param>
/// <returns><see cref="PreTransformationResult"/> that contains the transformed expression.</returns>
public static PreTransformationResult PreTransform(Expression expression, PreTransformationParameters parameters)
{
parameters.EvaluatableExpressionFilter = new NhEvaluatableExpressionFilter(parameters.SessionFactory);
parameters.QueryVariables = new Dictionary <ConstantExpression, QueryVariable>();
var partiallyEvaluatedExpression = NhPartialEvaluatingExpressionVisitor
.EvaluateIndependentSubtrees(expression, parameters);
return(new PreTransformationResult(
PreProcessor.Process(partiallyEvaluatedExpression),
parameters.SessionFactory,
parameters.QueryVariables));
}
public void ConstantInWhereDoesNotCauseManyKeys()
{
var q1 = (from c in db.Customers
where c.CustomerId == "ALFKI"
select c);
var q2 = (from c in db.Customers
where c.CustomerId == "ANATR"
select c);
var preTransformParameters = new PreTransformationParameters(QueryMode.Select, Sfi);
var preTransformResult = NhRelinqQueryParser.PreTransform(q1.Expression, preTransformParameters);
var parameters1 = ExpressionParameterVisitor.Visit(preTransformResult);
var k1 = ExpressionKeyVisitor.Visit(preTransformResult.Expression, parameters1, Sfi);
var preTransformResult2 = NhRelinqQueryParser.PreTransform(q2.Expression, preTransformParameters);
var parameters2 = ExpressionParameterVisitor.Visit(preTransformResult2);
var k2 = ExpressionKeyVisitor.Visit(preTransformResult2.Expression, parameters2, Sfi);
Assert.That(parameters1, Has.Count.GreaterThan(0), "parameters1");
Assert.That(parameters2, Has.Count.GreaterThan(0), "parameters2");
Assert.That(k2, Is.EqualTo(k1));
}
