public object Execute(Expression expression)
{
// Translate the expression tree
expression = LinqTranslatorVisitor.Translate(expression);
// Covert prediate (scalar) expressions to a source query
if (expression is APredicateExpression predicate)
{
FieldExpression value = new FieldExpression(predicate, "Scalar", "Value");
expression = new ScalarExpression(null, value);
}
// Covert aggregate (scalar) expressions to a source query
if (expression is AggregateExpression aggregate)
{
FieldExpression value = new FieldExpression(aggregate, "Scalar", "Value");
expression = new ScalarExpression(aggregate.Source, value);
}
// Execute the query
if (expression is ASourceExpression source)
{
return(connection.ExecuteQuery(source, visitor));
}
throw new NotSupportedException("The expression could not be converted to sql.");
}
/// <summary>
/// Translates the specified expression and its subtree to an <see cref="AExpression"/>.
/// </summary>
/// <param name="expression">The expression to modify.</param>
/// <returns>The converted expression tree.</returns>
public static Expression Translate(Expression expression)
{
LinqTranslatorVisitor visitor = new LinqTranslatorVisitor();
return(visitor.Visit(expression));
}