/// <summary>
/// Parses the new object that is part of the select expression with "as" based formatting
/// </summary>
private Expression VisitSelectNewExpression(NewExpression expression)
{
var arguments = expression.Arguments;
var members = expression.Members;
for (var i = 0; i < members.Count; i++)
{
if (i > 0)
{
_expression.Append(", ");
}
var expressionLength = _expression.Length;
VisitExpression(arguments[i]);
//only add 'as' part if the previous visitexpression has generated something.
if (_expression.Length > expressionLength)
{
_expression.AppendFormat(" as {0}", N1QlHelpers.EscapeIdentifier(members[i].Name));
}
else if (i > 0)
{
// nothing was added, so remove the extra comma
_expression.Length -= 2;
}
}
return(expression);
}
protected override Expression VisitMemberExpression(MemberExpression expression)
{
if (expression.Expression.Type.Assembly.GetName().Name == "mscorlib")
{
// For property getters on the core .Net classes, we don't want to just recurse through the .Net object model
// Instead, convert to a MethodCallExpression
// And it will pass through the appropriate IMethodCallTranslator
// (i.e. string.Length)
var propInfo = expression.Member as PropertyInfo;
if ((propInfo != null) && (propInfo.GetMethod != null) && (propInfo.GetMethod.GetParameters().Length == 0))
{
// Convert to a property getter method call
var newExpression = System.Linq.Expressions.Expression.Call(
expression.Expression,
propInfo.GetMethod);
return(VisitExpression(newExpression));
}
}
string memberName;
if (_queryGenerationContext.MemberNameResolver.TryResolveMemberName(expression.Member, out memberName))
{
VisitExpression(expression.Expression);
_expression.AppendFormat(".{0}", N1QlHelpers.EscapeIdentifier(memberName));
}
return(expression);
}
/// <summary>
/// Visits a nest against a constant expression, which must be an IBucketQueryable implementation
/// </summary>
/// <param name="nestClause">Nest clause being visited</param>
/// <param name="constantExpression">Constant expression that is the InnerSequence of the NestClause</param>
/// <param name="itemName">Name to be used when referencing the data being nested</param>
/// <returns>N1QlFromQueryPart to be added to the QueryPartsAggregator</returns>
private N1QlFromQueryPart VisitConstantExpressionNestClause(NestClause nestClause, ConstantExpression constantExpression, string itemName)
{
string bucketName = null;
if (constantExpression != null)
{
var bucketQueryable = constantExpression.Value as IBucketQueryable;
if (bucketQueryable != null)
{
bucketName = bucketQueryable.BucketName;
}
}
if (bucketName == null)
{
throw new NotSupportedException("N1QL Nests Must Be Against IBucketQueryable");
}
return(new N1QlFromQueryPart()
{
Source = N1QlHelpers.EscapeIdentifier(bucketName),
ItemName = itemName,
OnKeys = GetN1QlExpression(nestClause.KeySelector),
JoinType = nestClause.IsLeftOuterNest ? "LEFT OUTER NEST" : "INNER NEST"
});
}
public void SetExtentName(IQuerySource querySource, string extentName)
{
if (querySource == null)
{
throw new ArgumentNullException("extentName");
}
if (string.IsNullOrEmpty(extentName))
{
return;
}
if (_extentDictionary.ContainsKey(querySource))
{
throw new InvalidOperationException("Cannot set the extent name on a query source which already has a name.");
}
_extentDictionary[querySource] = N1QlHelpers.EscapeIdentifier(extentName);
}
protected override Expression VisitMember(MemberExpression expression)
{
if (expression.Expression.Type.GetTypeInfo().Assembly.Equals(Mscorlib))
{
// For property getters on the core .Net classes, we don't want to just recurse through the .Net object model
// Instead, convert to a MethodCallExpression
// And it will pass through the appropriate IMethodCallTranslator
// (i.e. string.Length)
var propInfo = expression.Member as PropertyInfo;
if ((propInfo != null) && (propInfo.GetMethod != null) && (propInfo.GetMethod.GetParameters().Length == 0))
{
// Convert to a property getter method call
var newExpression = System.Linq.Expressions.Expression.Call(
expression.Expression,
propInfo.GetMethod);
return(Visit(newExpression));
}
}
string memberName;
if (_queryGenerationContext.MemberNameResolver.TryResolveMemberName(expression.Member, out memberName))
{
var querySourceExpression = expression.Expression as QuerySourceReferenceExpression;
if ((querySourceExpression != null) &&
(_queryGenerationContext.ExtentNameProvider.GetExtentName(
querySourceExpression.ReferencedQuerySource) == ""))
{
// This query source has a blank extent name, so we don't need to reference the extent to access the member
_expression.Append(N1QlHelpers.EscapeIdentifier(memberName));
}
else
{
Visit(expression.Expression);
_expression.AppendFormat(".{0}", N1QlHelpers.EscapeIdentifier(memberName));
}
}
return(expression);
}
/// <summary>
/// Visits a join against a constant expression, which must be an IBucketQueryable implementation
/// </summary>
/// <param name="joinClause">Join clause being visited</param>
/// <param name="constantExpression">Constant expression that is the InnerSequence of the JoinClause</param>
/// <returns>N1QlFromQueryPart to be added to the QueryPartsAggregator. JoinType is defaulted to INNER JOIN.</returns>
/// <remarks>The InnerKeySelector must be selecting the N1Ql.Key of the InnerSequence</remarks>
private N1QlFromQueryPart VisitConstantExpressionJoinClause(JoinClause joinClause, ConstantExpression constantExpression)
{
string bucketName = null;
if (constantExpression != null)
{
var bucketQueryable = constantExpression.Value as IBucketQueryable;
if (bucketQueryable != null)
{
bucketName = bucketQueryable.BucketName;
}
}
if (bucketName == null)
{
throw new NotSupportedException("N1QL Joins Must Be Against IBucketQueryable");
}
var keyExpression = joinClause.InnerKeySelector as MethodCallExpression;
if ((keyExpression == null) ||
(keyExpression.Method != typeof(N1Ql).GetMethod("Key")) ||
(keyExpression.Arguments.Count != 1))
{
throw new NotSupportedException("N1QL Join Selector Must Be A Call To N1Ql.Key");
}
if (!(keyExpression.Arguments[0] is QuerySourceReferenceExpression))
{
throw new NotSupportedException("N1QL Join Selector Call To N1Ql.Key Must Reference The Inner Sequence");
}
return(new N1QlFromQueryPart()
{
Source = N1QlHelpers.EscapeIdentifier(bucketName),
ItemName = GetExtentName(joinClause),
OnKeys = GetN1QlExpression(joinClause.OuterKeySelector),
JoinType = "INNER JOIN"
});
}
private string GetNextExtentName()
{
return(N1QlHelpers.EscapeIdentifier(string.Format(ExtentNameFormat, ++_extentIndex)));
}
/// <summary>
/// Parses the new object that is part of the select expression with "as" based formatting.
/// Can accept either a NewExpression or MemberInitExpression
/// </summary>
private Expression VisitSelectNewExpression(Expression expression)
{
IList <Expression> arguments;
IList <MemberInfo> members;
var memberInitExpression = expression as MemberInitExpression;
if (memberInitExpression != null)
{
if (memberInitExpression.NewExpression.Arguments.Count > 0)
{
throw new NotSupportedException("New Objects Must Be Initialized With A Parameterless Constructor");
}
if (memberInitExpression.Bindings.Any(p => p.BindingType != MemberBindingType.Assignment))
{
throw new NotSupportedException("New Objects Must Be Initialized With Assignments Only");
}
arguments = memberInitExpression.Bindings.Cast <MemberAssignment>().Select(p => p.Expression).ToList();
members = memberInitExpression.Bindings.Select(p => p.Member).ToList();
}
else
{
var newExpression = expression as NewExpression;
if (newExpression == null)
{
throw new NotSupportedException("Unsupported Select Clause Expression");
}
arguments = newExpression.Arguments;
members = newExpression.Members;
}
for (var i = 0; i < members.Count; i++)
{
if (i > 0)
{
_expression.Append(", ");
}
var expressionLength = _expression.Length;
Visit(arguments[i]);
//only add 'as' part if the previous visitexpression has generated something.
if (_expression.Length > expressionLength)
{
if (!QueryGenerationContext.MemberNameResolver.TryResolveMemberName(members[i], out var memberName))
{
memberName = members[i].Name;
}
_expression.AppendFormat(" as {0}", N1QlHelpers.EscapeIdentifier(memberName));
}
else if (i > 0)
{
// nothing was added, so remove the extra comma
_expression.Length -= 2;
}
}
return(expression);
}
private string GetSelectParameters(SelectClause selectClause, QueryModel queryModel)
{
string expression;
if (selectClause.Selector.GetType() == typeof(QuerySourceReferenceExpression))
{
if (_queryPartsAggregator.AggregateFunction == null)
{
expression = GetN1QlExpression(selectClause.Selector);
if (_queryPartsAggregator.QueryType != N1QlQueryType.Array)
{
expression = string.Concat(expression, ".*");
}
}
else
{
// for aggregates, just use "*" (i.e. AggregateFunction = "COUNT", expression = "*" results in COUNT(*)"
expression = "*";
}
}
else if (selectClause.Selector.NodeType == ExpressionType.New)
{
if (_queryPartsAggregator.QueryType != N1QlQueryType.Array)
{
var selector = selectClause.Selector as NewExpression;
if (_groupingStatus == GroupingStatus.AfterGroupSubquery)
{
// SELECT clauses must be remapped to refer directly to the extents in the grouping subquery
// rather than refering to the output of the grouping subquery
selector = (NewExpression)TransformingExpressionTreeVisitor.Transform(selector, _groupingExpressionTransformerRegistry);
}
expression =
N1QlExpressionTreeVisitor.GetN1QlSelectNewExpression(selector, _queryGenerationContext);
}
else
{
expression = GetN1QlExpression(selectClause.Selector);
}
}
else
{
expression = GetN1QlExpression(selectClause.Selector);
if ((_queryPartsAggregator.QueryType == N1QlQueryType.Subquery) || (_queryPartsAggregator.QueryType == N1QlQueryType.Array))
{
// For LINQ, this subquery is expected to return a list of the specific property being selected
// But N1QL will always return a list of objects with a single property
// So we need to use an ARRAY statement to convert the list
_queryPartsAggregator.ArrayPropertyExtractionPart = N1QlHelpers.EscapeIdentifier("result");
expression += " as " + _queryPartsAggregator.ArrayPropertyExtractionPart;
}
}
return(expression);
}
/// <exception cref="NotSupportedException">N1Ql Bucket Subqueries Require A UseKeys Call</exception>
public override void VisitMainFromClause(MainFromClause fromClause, QueryModel queryModel)
{
var bucketConstantExpression = fromClause.FromExpression as ConstantExpression;
if ((bucketConstantExpression != null) &&
typeof(IBucketQueryable).IsAssignableFrom(bucketConstantExpression.Type))
{
if (_isSubQuery && !queryModel.BodyClauses.Any(p => p is UseKeysClause))
{
throw new NotSupportedException("N1Ql Bucket Subqueries Require A UseKeys Call");
}
_queryPartsAggregator.AddFromPart(new N1QlFromQueryPart()
{
Source = N1QlHelpers.EscapeIdentifier(((IBucketQueryable)bucketConstantExpression.Value).BucketName),
ItemName = GetExtentName(fromClause)
});
}
else if (fromClause.FromExpression.NodeType == ExpressionType.MemberAccess)
{
if (!_isSubQuery)
{
throw new NotSupportedException("Member Access In The Main From Clause Is Only Supported In Subqueries");
}
_queryPartsAggregator.AddFromPart(new N1QlFromQueryPart()
{
Source = GetN1QlExpression((MemberExpression)fromClause.FromExpression),
ItemName = GetExtentName(fromClause)
});
// This is an Array type subquery, since we're querying against a member not a bucket
_queryPartsAggregator.QueryType = N1QlQueryType.Array;
}
else if (fromClause.FromExpression.NodeType == SubQueryExpression.ExpressionType)
{
var subQuery = (SubQueryExpression)fromClause.FromExpression;
if (!subQuery.QueryModel.ResultOperators.Any(p => p is GroupResultOperator))
{
throw new NotSupportedException("Subqueries In The Main From Clause Are Only Supported For Grouping");
}
_groupingStatus = GroupingStatus.InGroupSubquery;
_queryGenerationContext.GroupingQuerySource = new QuerySourceReferenceExpression(fromClause);
VisitQueryModel(subQuery.QueryModel);
_groupingStatus = GroupingStatus.AfterGroupSubquery;
}
else if (fromClause.FromExpression.NodeType == QuerySourceReferenceExpression.ExpressionType)
{
if (!fromClause.FromExpression.Equals(_queryGenerationContext.GroupingQuerySource))
{
throw new NotSupportedException("From Clauses May Not Reference Any Query Source Other Than The Grouping Subquery");
}
// We're performing an aggregate against a group
_queryPartsAggregator.QueryType = N1QlQueryType.Aggregate;
// Ensure that we use the same extent name as the grouping
_queryGenerationContext.ExtentNameProvider.LinkExtents(_queryGenerationContext.GroupingQuerySource.ReferencedQuerySource, fromClause);
}
base.VisitMainFromClause(fromClause, queryModel);
}
private string GetSelectParameters(SelectClause selectClause, QueryModel queryModel)
{
string expression;
if (selectClause.Selector.GetType() == typeof(QuerySourceReferenceExpression))
{
if (_queryPartsAggregator.AggregateFunction == null)
{
expression = GetN1QlExpression(selectClause.Selector);
if (_queryPartsAggregator.QueryType != N1QlQueryType.Array)
{
expression = string.Concat(expression, ".*");
}
}
else
{
// for aggregates, just use "*" (i.e. AggregateFunction = "COUNT", expression = "*" results in COUNT(*)"
ResultExtractionRequired = true;
_queryPartsAggregator.PropertyExtractionPart = N1QlHelpers.EscapeIdentifier("result");
expression = "*";
}
}
else if (selectClause.Selector.NodeType == ExpressionType.New)
{
if (_queryPartsAggregator.QueryType != N1QlQueryType.Array)
{
var selector = selectClause.Selector as NewExpression;
if (_groupingStatus == GroupingStatus.AfterGroupSubquery)
{
// SELECT clauses must be remapped to refer directly to the extents in the grouping subquery
// rather than refering to the output of the grouping subquery
selector = (NewExpression)TransformingExpressionTreeVisitor.Transform(selector, _groupingExpressionTransformerRegistry);
}
expression =
N1QlExpressionTreeVisitor.GetN1QlSelectNewExpression(selector, _queryGenerationContext);
}
else
{
expression = GetN1QlExpression(selectClause.Selector);
}
}
else
{
expression = GetN1QlExpression(selectClause.Selector);
if (_queryPartsAggregator.QueryType == N1QlQueryType.Subquery)
{
// For LINQ, this subquery is expected to return a list of the specific property being selected
// But N1QL will always return a list of objects with a single property
// So we need to use an ARRAY statement to convert the list
_queryPartsAggregator.PropertyExtractionPart = N1QlHelpers.EscapeIdentifier("result");
expression += " as " + _queryPartsAggregator.PropertyExtractionPart;
}
else
{
// This is a select expression on the main query that doesn't use a "new" clause, and isn't against an extent
// So it will return an array of objects with properties, while LINQ is expecting an array of values
// Since we can't extract the properties from the object in N1QL like we can with subqueries
// We need to indicate to the BucketQueryExecutor that it will need to extract the properties
_queryPartsAggregator.PropertyExtractionPart = N1QlHelpers.EscapeIdentifier("result");
ResultExtractionRequired = true;
}
}
return(expression);
}
