public async ValueTask <object> ExecuteScalar(string sql, SqlParameters parameters = null, object data = null)
{
sql = OffsetLimitUtils.TransformQuery(sql);
var tree = _sqlParser.Parse(sql);
var mainVisitor = new MainVisitor(new VisitorMetadata(parameters, _tablesMetadata, _searchExpressionProvider, _operationsProvider));
tree.Accept(mainVisitor);
//Convert into execute stages
var executeStages = _stageConverter.Convert(mainVisitor.Stages);
var result = await _queryExecutor.Execute(executeStages, data);
var enumerator = result.Result.GetEnumerator();
if (!enumerator.MoveNext())
{
return(null);
}
else
{
var obj = enumerator.Current;
return(AnonTypeUtils.GetDelegates(obj.GetType())[0](obj));
}
}
public async ValueTask <SelectResult> Execute(IQueryable queryable, ExecuteAggregateFunctionStage executeAggregateFunctionStage)
{
var result = await ExecuteAggregateFunction((IQueryable <Entity>) queryable, executeAggregateFunctionStage);
var outType = typeof(OutType);
var anonType = AnonType.GetAnonType(outType);
var getDelegate = AnonTypeUtils.GetDelegates(anonType)[0];
var columnMetadata = new ColumnMetadata(executeAggregateFunctionStage.ColumnName, result.GetType(), getDelegate);
List <AnonType <OutType> > output = new List <AnonType <OutType> >()
{
new AnonType <OutType>()
{
P0 = result
}
};
return(new SelectResult(output.AsQueryable(), ImmutableList.Create(columnMetadata)));
}
public static SelectStage GetSelectStage(
IQueryStage previousStage,
IList <SqlParser.Expressions.SelectExpression> selectElements,
VisitorMetadata visitorMetadata,
HashSet <PropertyInfo> usedProperties)
{
ISelectVisitor selectVisitor;
if (previousStage is GroupedStage groupedStage)
{
selectVisitor = new SelectAggregationVisitor(groupedStage, visitorMetadata);
}
else
{
selectVisitor = new SelectPlainVisitor(previousStage, visitorMetadata);
}
foreach (var selectElement in selectElements)
{
selectVisitor.VisitSelect(selectElement);
}
foreach (var property in selectVisitor.UsedProperties)
{
usedProperties.Add(property);
}
var selects = selectVisitor.SelectExpressions;
Debug.Assert(selects != null);
Debug.Assert(selects.Count > 0);
var typeBuilder = SqlTypeInfo.NewBuilder();
Type[] propertyTypes = new Type[selects.Count];
for (int i = 0; i < selects.Count; i++)
{
propertyTypes[i] = selects[i].Expression.Type;
}
var anonType = AnonType.GetAnonType(propertyTypes);
var getDelegates = AnonTypeUtils.GetDelegates(anonType);
NewExpression newExpression = Expression.New(anonType);
List <MemberAssignment> assignments = new List <MemberAssignment>();
var columnsBuilder = ImmutableList.CreateBuilder <ColumnMetadata>();
for (int i = 0; i < selects.Count; i++)
{
columnsBuilder.Add(new ColumnMetadata(selects[i].Alias, selects[i].Expression.Type, getDelegates[i]));
var propertyInfo = anonType.GetProperty($"P{i}");
var assignment = Expression.Bind(propertyInfo, selects[i].Expression);
assignments.Add(assignment);
typeBuilder.AddProperty(selects[i].Alias, propertyInfo);
}
var memberInit = Expression.MemberInit(newExpression, assignments);
return(new SelectStage(typeBuilder.Build(),
Expression.Parameter(anonType),
memberInit,
anonType,
previousStage.CurrentType,
previousStage.ParameterExpression,
previousStage.FromAliases,
columnsBuilder.ToImmutable()));
}
