/// <summary>
/// This is an internal API that supports the Entity Framework Core infrastructure and not subject to
/// the same compatibility standards as public APIs. It may be changed or removed without notice in
/// any release. You should only use it directly in your code with extreme caution and knowing that
/// doing so can result in application failures when updating to a new Entity Framework Core release.
/// </summary>
protected override Expression VisitSelect(SelectExpression selectExpression)
{
Check.NotNull(selectExpression, nameof(selectExpression));
_sqlBuilder.Append("SELECT ");
if (selectExpression.IsDistinct)
{
_sqlBuilder.Append("DISTINCT ");
}
if (selectExpression.Projection.Count > 0)
{
if (selectExpression.Projection.Any(p => !string.IsNullOrEmpty(p.Alias) && p.Alias != p.Name) &&
!selectExpression.Projection.Any(p => p.Expression is SqlFunctionExpression)) // Aggregates are not allowed
{
_useValueProjection = true;
_sqlBuilder.Append("VALUE {");
GenerateList(selectExpression.Projection, e => Visit(e));
_sqlBuilder.Append("}");
_useValueProjection = false;
}
else
{
GenerateList(selectExpression.Projection, e => Visit(e));
}
}
else
{
_sqlBuilder.Append("1");
}
_sqlBuilder.AppendLine();
_sqlBuilder.Append("FROM root ");
Visit(selectExpression.FromExpression);
_sqlBuilder.AppendLine();
if (selectExpression.Predicate != null)
{
_sqlBuilder.Append("WHERE ");
Visit(selectExpression.Predicate);
}
if (selectExpression.Orderings.Any())
{
_sqlBuilder.AppendLine().Append("ORDER BY ");
GenerateList(selectExpression.Orderings, e => Visit(e));
}
if (selectExpression.Offset != null ||
selectExpression.Limit != null)
{
_sqlBuilder.AppendLine().Append("OFFSET ");
if (selectExpression.Offset != null)
{
Visit(selectExpression.Offset);
}
else
{
_sqlBuilder.Append("0");
}
_sqlBuilder.Append(" LIMIT ");
if (selectExpression.Limit != null)
{
Visit(selectExpression.Limit);
}
else
{
// TODO: See Issue#18923
throw new InvalidOperationException(CosmosStrings.OffsetRequiresLimit);
}
}
return(selectExpression);
}
/// <summary>
/// This is an internal API that supports the Entity Framework Core infrastructure and not subject to
/// the same compatibility standards as public APIs. It may be changed or removed without notice in
/// any release. You should only use it directly in your code with extreme caution and knowing that
/// doing so can result in application failures when updating to a new Entity Framework Core release.
/// </summary>
protected override Expression VisitChildren(ExpressionVisitor visitor)
{
Check.NotNull(visitor, nameof(visitor));
var changed = false;
var projections = new List <ProjectionExpression>();
IDictionary <ProjectionMember, Expression> projectionMapping;
if (Projection.Any())
{
projectionMapping = _projectionMapping;
foreach (var item in Projection)
{
var projection = (ProjectionExpression)visitor.Visit(item);
projections.Add(projection);
changed |= projection != item;
}
}
else
{
projectionMapping = new Dictionary <ProjectionMember, Expression>();
foreach (var mapping in _projectionMapping)
{
var newProjection = visitor.Visit(mapping.Value);
changed |= newProjection != mapping.Value;
projectionMapping[mapping.Key] = newProjection;
}
}
var fromExpression = (RootReferenceExpression)visitor.Visit(FromExpression);
changed |= fromExpression != FromExpression;
var predicate = (SqlExpression)visitor.Visit(Predicate);
changed |= predicate != Predicate;
var orderings = new List <OrderingExpression>();
foreach (var ordering in _orderings)
{
var orderingExpression = (SqlExpression)visitor.Visit(ordering.Expression);
changed |= orderingExpression != ordering.Expression;
orderings.Add(ordering.Update(orderingExpression));
}
var offset = (SqlExpression)visitor.Visit(Offset);
changed |= offset != Offset;
var limit = (SqlExpression)visitor.Visit(Limit);
changed |= limit != Limit;
if (changed)
{
var newSelectExpression = new SelectExpression(projections, fromExpression, orderings)
{
_projectionMapping = projectionMapping,
Predicate = predicate,
Offset = offset,
Limit = limit,
IsDistinct = IsDistinct
};
return(newSelectExpression);
}
return(this);
}
/// <summary> /// This is an internal API that supports the Entity Framework Core infrastructure and not subject to /// the same compatibility standards as public APIs. It may be changed or removed without notice in /// any release. You should only use it directly in your code with extreme caution and knowing that /// doing so can result in application failures when updating to a new Entity Framework Core release. /// </summary> protected abstract Expression VisitSelect([NotNull] SelectExpression selectExpression);
/// <summary>
/// This is an internal API that supports the Entity Framework Core infrastructure and not subject to
/// the same compatibility standards as public APIs. It may be changed or removed without notice in
/// any release. You should only use it directly in your code with extreme caution and knowing that
/// doing so can result in application failures when updating to a new Entity Framework Core release.
/// </summary>
protected override Expression VisitSelect(SelectExpression selectExpression)
{
Check.NotNull(selectExpression, nameof(selectExpression));
_sqlBuilder.Append("SELECT ");
if (selectExpression.IsDistinct)
{
_sqlBuilder.Append("DISTINCT ");
}
if (selectExpression.Projection.Any())
{
GenerateList(selectExpression.Projection, e => Visit(e));
}
else
{
_sqlBuilder.Append("1");
}
_sqlBuilder.AppendLine();
_sqlBuilder.Append("FROM root ");
Visit(selectExpression.FromExpression);
_sqlBuilder.AppendLine();
if (selectExpression.Predicate != null)
{
_sqlBuilder.Append("WHERE ");
Visit(selectExpression.Predicate);
}
if (selectExpression.Orderings.Any())
{
_sqlBuilder.AppendLine().Append("ORDER BY ");
GenerateList(selectExpression.Orderings, e => Visit(e));
}
if (selectExpression.Offset != null ||
selectExpression.Limit != null)
{
_sqlBuilder.AppendLine().Append("OFFSET ");
if (selectExpression.Offset != null)
{
Visit(selectExpression.Offset);
}
else
{
_sqlBuilder.Append("0");
}
_sqlBuilder.Append(" LIMIT ");
if (selectExpression.Limit != null)
{
Visit(selectExpression.Limit);
}
else
{
// TODO: See Issue#18923
throw new InvalidOperationException("Cosmos Sql API does not support Offset without Limit.");
}
}
return(selectExpression);
}
/// <summary> /// This is an internal API that supports the Entity Framework Core infrastructure and not subject to /// the same compatibility standards as public APIs. It may be changed or removed without notice in /// any release. You should only use it directly in your code with extreme caution and knowing that /// doing so can result in application failures when updating to a new Entity Framework Core release. /// </summary> protected abstract Expression VisitSelect(SelectExpression selectExpression);
/// <summary>
/// This is an internal API that supports the Entity Framework Core infrastructure and not subject to
/// the same compatibility standards as public APIs. It may be changed or removed without notice in
/// any release. You should only use it directly in your code with extreme caution and knowing that
/// doing so can result in application failures when updating to a new Entity Framework Core release.
/// </summary>
protected override Expression VisitSelect(SelectExpression selectExpression)
{
_sqlBuilder.Append("SELECT ");
if (selectExpression.IsDistinct)
{
_sqlBuilder.Append("DISTINCT ");
}
if (selectExpression.Projection.Any())
{
GenerateList(selectExpression.Projection, e => Visit(e));
}
else
{
_sqlBuilder.Append("1");
}
_sqlBuilder.AppendLine();
_sqlBuilder.Append("FROM root ");
Visit(selectExpression.FromExpression);
_sqlBuilder.AppendLine();
if (selectExpression.Predicate != null)
{
_sqlBuilder.Append("WHERE ");
Visit(selectExpression.Predicate);
}
if (selectExpression.Orderings.Any())
{
_sqlBuilder.AppendLine().Append("ORDER BY ");
GenerateList(selectExpression.Orderings, e => Visit(e));
}
if (selectExpression.Offset != null ||
selectExpression.Limit != null)
{
_sqlBuilder.AppendLine().Append("OFFSET ");
if (selectExpression.Offset != null)
{
Visit(selectExpression.Offset);
}
else
{
_sqlBuilder.Append("0");
}
_sqlBuilder.Append(" LIMIT ");
if (selectExpression.Limit != null)
{
Visit(selectExpression.Limit);
}
else
{
throw new InvalidOperationException(CoreStrings.QueryFailed(selectExpression.Print(), GetType().Name));
}
}
return(selectExpression);
}