public static SelectFromBuilder FromCombinedExpression <TCombinedModel, TNewModel>(TablesList tablesList, Expression <Func <TCombinedModel, TNewModel> > prBody)
{
var builder = new SelectFromBuilder();
builder.LeftJoinsExpressions = tablesList.JoinExpressions;
var options = new EvaluationOptions();
foreach (var tablePlaceholder in tablesList.Tables)
{
builder.AddTable(tablePlaceholder);
// options.ParameterToTableAlias.Add(tablePlaceholder.Name, tablePlaceholder);
}
var tableToPlaceholder = tablesList.Tables.ToDictionary(x => x.Name);
TypedExpression exp;
switch (prBody.Body)
{
/* For:
* .Select(x => new {
* M1 = x.M1,
* M2_name = x.M2.Name1,
* M3_calc = x.M2.Id * 2,
* })
*/
case NewExpression newExpression:
{
IEnumerable <Expression> args = newExpression.Arguments;
var resultProcessor = new AnonymousTypeSelectResultProcessor <TNewModel>();
builder.SelectResultProcessor = resultProcessor;
foreach (var argExpression in args)
{
// Member is Table (like M1 = x.M1)
if (argExpression is MemberExpression memberExpression && ModelsRegistry.IsTable(memberExpression.Type))
{
var tablePlaceholder = tableToPlaceholder[memberExpression.Member.Name];
var table = tablePlaceholder.Table;
var tableTestRawQuery = new RawQuery();
tableTestRawQuery.AppendTable(tablePlaceholder);
tableTestRawQuery.Append(" IS NULL");
builder.AddSelectPart(tableTestRawQuery, KDPgValueTypeInstances.Boolean);
foreach (var column in table.Columns)
{
var rq = new RawQuery();
rq.AppendColumn(column, tablePlaceholder);
builder.AddSelectPart(rq, column.Type);
}
resultProcessor.AddModelEntry(table);
}