public IFromTableExecutor GetFromTableExecutor(ExecuteFromTableStage executeFromTableStage)
{
if (!executors.TryGetValue(executeFromTableStage.EntityType, out var executor))
{
var t = typeof(DefaultFromTableExecutor <>).MakeGenericType(executeFromTableStage.EntityType);
executor = (IFromTableExecutor)Activator.CreateInstance(t);
executors.TryAdd(executeFromTableStage.EntityType, executor);
}
return(executor);
}
protected Expression <Func <Entity, bool> > GetWhereLambda(ExecuteFromTableStage stage)
{
return(Expression.Lambda <Func <Entity, bool> >(stage.WhereExpression, stage.ParameterExpression));
}
protected Expression <Func <Entity, Entity> > GetSelectLambda(ExecuteFromTableStage stage)
{
var lambda = Expression.Lambda <Func <Entity, Entity> >(stage.SelectExpression, stage.ParameterExpression);
return(lambda);
}
public abstract ValueTask <IQueryable <Entity> > GetTable(ISqlTableResolver tableResolver, ExecuteFromTableStage executeFromTableStage, object additionalData);
public async ValueTask <IQueryable> Execute(ISqlTableResolver tableResolver, ExecuteFromTableStage executeFromTableStage, object additionalData)
{
return(await GetTable(tableResolver, executeFromTableStage, additionalData));
}
public ValueTask <IQueryable> Visit(ExecuteFromTableStage executeFromTableStage)
{
var fromTableExecutor = _fromTableExecutorFactory.GetFromTableExecutor(executeFromTableStage);
return(fromTableExecutor.Execute(_tableResolver, executeFromTableStage, data));
}
public override async ValueTask <IQueryable <Entity> > GetTable(ISqlTableResolver tableResolver, ExecuteFromTableStage executeFromTableStage, object additionalData)
{
QueryOptions queryOptions = new QueryOptions(
executeFromTableStage.ParameterExpression,
executeFromTableStage.SelectExpression,
executeFromTableStage.WhereExpression,
executeFromTableStage.Limit,
executeFromTableStage.Offset,
executeFromTableStage.ContainsFullTextSearch,
executeFromTableStage.Parameters);
var queryable = (IQueryable <Entity>) await tableResolver.ResolveTableName(executeFromTableStage.TableName, additionalData, queryOptions);
//Check that we are not using any in memory queryable, since this select will only cost extra operations
//without any gain
if (!((queryable is EnumerableQuery) || (queryable is Array)) && queryOptions.TryGetSelectExpression <Entity>(out var select))
{
queryable = queryable.Select(select);
}
if (queryOptions.TryGetWhereExpression <Entity>(out var where))
{
queryable = queryable.Where(where);
}
if (queryOptions.TryGetOffset(out var offset))
{
queryable = queryable.Skip(offset);
}
if (queryOptions.TryGetLimit(out var limit))
{
queryable = queryable.Take(limit);
}
return(queryable);
}
