private static ObjectQueryState BuildSelectOrSelectValue(ObjectQueryState query, string alias, string projection, ObjectParameter[] parameters, string projectOp, Type elementType)
{
Debug.Assert(!StringUtil.IsNullOrEmptyOrWhiteSpace(alias), "Invalid alias");
Debug.Assert(!StringUtil.IsNullOrEmptyOrWhiteSpace(projection), "Invalid projection");
string queryText = GetCommandText(query);
// Build the new query string - "<project op> <projection> FROM (<this query>) AS <alias>"
int queryLength = projectOp.Length +
projection.Length +
_fromOp.Length +
queryText.Length +
_asOp.Length +
alias.Length;
StringBuilder builder = new StringBuilder(queryLength);
builder.Append(projectOp);
builder.Append(projection);
builder.Append(_fromOp);
builder.Append(queryText);
builder.Append(_asOp);
builder.Append(alias);
// Create a new EntitySqlQueryImplementation that uses the new query as its command text.
// Span should not be carried over from a Select or SelectValue operation.
return(NewBuilderQuery(query, elementType, builder, null, MergeParameters(query.ObjectContext, query.Parameters, parameters)));
}
internal static ObjectQueryState GroupBy(ObjectQueryState query, string alias, string keys, string projection, ObjectParameter[] parameters)
{
Debug.Assert(!StringUtil.IsNullOrEmptyOrWhiteSpace(alias), "Invalid alias");
Debug.Assert(!StringUtil.IsNullOrEmptyOrWhiteSpace(alias), "Invalid keys");
Debug.Assert(!StringUtil.IsNullOrEmptyOrWhiteSpace(projection), "Invalid projection");
string queryText = GetCommandText(query);
// Build the new query string:
// "SELECT <projection> FROM (<this query>) AS <alias> GROUP BY <keys>"
int queryLength = _selectOp.Length +
projection.Length +
_fromOp.Length +
queryText.Length +
_asOp.Length +
alias.Length +
_groupByOp.Length +
keys.Length;
StringBuilder builder = new StringBuilder(queryLength);
builder.Append(_selectOp);
builder.Append(projection);
builder.Append(_fromOp);
builder.Append(queryText);
builder.Append(_asOp);
builder.Append(alias);
builder.Append(_groupByOp);
builder.Append(keys);
// Create a new EntitySqlQueryImplementation that uses the new query as its command text.
// Span should not be carried over from a GroupBy operation.
return(NewBuilderQuery(query, typeof(DbDataRecord), builder, null, MergeParameters(query.ObjectContext, query.Parameters, parameters)));
}
// SetOp helper - note that this doesn't merge Spans, since Except uses the original query's Span
// while Intersect/Union/UnionAll use the merged Span.
private static ObjectQueryState BuildSetOp(ObjectQueryState leftQuery, ObjectQueryState rightQuery, Span newSpan, string setOp)
{
// Assert that the arguments aren't null (should have been verified by ObjectQuery)
Debug.Assert(leftQuery != null, "Left query is null?");
Debug.Assert(rightQuery != null, "Right query is null?");
Debug.Assert(leftQuery.ElementType.Equals(rightQuery.ElementType), "Incompatible element types in arguments to Except<T>/Intersect<T>/Union<T>/UnionAll<T>?");
// Retrieve the left and right arguments to the set operation -
// this will throw if either input query is not an Entity-SQL query.
string left = GetCommandText(leftQuery);
string right = GetCommandText(rightQuery);
// ObjectQuery arguments must be associated with the same ObjectContext instance as the implemented query
if (!object.ReferenceEquals(leftQuery.ObjectContext, rightQuery.ObjectContext))
{
throw EntityUtil.Argument(System.Data.Entity.Strings.ObjectQuery_QueryBuilder_InvalidQueryArgument, "query");
}
// Create a string builder only large enough to contain the new query text
int queryLength = _setOpProlog.Length + left.Length + setOp.Length + right.Length + _setOpEpilog.Length;
StringBuilder builder = new StringBuilder(queryLength);
// Build the new query
builder.Append(_setOpProlog);
builder.Append(left);
builder.Append(setOp);
builder.Append(right);
builder.Append(_setOpEpilog);
// Create a new query implementation and apply the state of this implementation to it.
// The Span of the query argument will be merged into the new query's Span by the caller, iff the Set Op is NOT Except.
// See the Except, Intersect, Union and UnionAll methods in this class for examples.
return(NewBuilderQuery(leftQuery, leftQuery.ElementType, builder, newSpan, MergeParameters(leftQuery.Parameters, rightQuery.Parameters)));
}
internal static ObjectQueryState OfType(ObjectQueryState query, EdmType newType, Type clrOfType)
{
Debug.Assert(newType != null, "OfType cannot be null");
Debug.Assert(Helper.IsEntityType(newType) || Helper.IsComplexType(newType), "OfType must be Entity or Complex type");
string queryText = GetCommandText(query);
// Build the new query string - "OFTYPE((<query>), [<type namespace>].[<type name>])"
int queryLength = _ofTypeProlog.Length +
queryText.Length +
_ofTypeInfix.Length +
newType.NamespaceName.Length +
(newType.NamespaceName != string.Empty ? _ofTypeInfix2.Length : 0) +
newType.Name.Length +
_ofTypeEpilog.Length;
StringBuilder builder = new StringBuilder(queryLength);
builder.Append(_ofTypeProlog);
builder.Append(queryText);
builder.Append(_ofTypeInfix);
if (newType.NamespaceName != string.Empty)
{
builder.Append(newType.NamespaceName);
builder.Append(_ofTypeInfix2);
}
builder.Append(newType.Name);
builder.Append(_ofTypeEpilog);
// Create a new EntitySqlQueryImplementation that uses the new query as its command text.
// Span is carried over, no adjustment is needed
return(NewBuilderQuery(query, clrOfType, builder, query.Span, ObjectParameterCollection.DeepCopy(query.Parameters)));
}
/// <summary>
/// Helper method used to create an ObjectQuery based on an underlying ObjectQueryState instance.
/// Although not called directly, this method must be public to be reliably callable from <see cref="CreateQuery()"/> using reflection.
/// </summary>
/// <typeparam name="TResultType">The required element type of the new ObjectQuery</typeparam>
/// <param name="queryState">The underlying ObjectQueryState instance that should back the returned ObjectQuery</param>
/// <returns>A new ObjectQuery based on the specified query state, with the specified element type</returns>
public static ObjectQuery <TResultType> CreateObjectQuery <TResultType>(ObjectQueryState queryState)
{
Debug.Assert(queryState != null, "Query state is required");
Debug.Assert(typeof(TResultType) == queryState.ElementType, "Element type mismatch");
return(new ObjectQuery <TResultType>(queryState));
}
internal static ObjectQueryState UnionAll(ObjectQueryState leftQuery, ObjectQueryState rightQuery)
{
// Ensure the Spans of the query arguments are merged into the new query's Span.
Span newSpan = Span.CopyUnion(leftQuery.Span, rightQuery.Span);
// Call the SetOp helper.
return(BuildSetOp(leftQuery, rightQuery, newSpan, _unionAllOp));
}
/// <summary>
/// Sets the values the <see cref="PlanCachingEnabled"/> and <see cref="UserSpecifiedMergeOption"/> properties on
/// <paramref name="other"/> to match the values of the corresponding properties on this instance.
/// </summary>
/// <param name="other">The query state to which this instances settings should be applied.</param>
internal void ApplySettingsTo(ObjectQueryState other)
{
other.PlanCachingEnabled = this.PlanCachingEnabled;
other.UserSpecifiedMergeOption = this.UserSpecifiedMergeOption;
// _cachedPlan is intentionally not copied over - since the parameters of 'other' would have to be locked as
// soon as its execution plan was set, and that may not be appropriate at the time ApplySettingsTo is called.
}
/// <summary>
/// Helper method to extract the Entity-SQL command text from an <see cref="ObjectQueryState"/> instance if that
/// instance models an Entity-SQL-backed ObjectQuery, or to throw an exception indicating that query builder methods
/// are not supported on this query.
/// </summary>
/// <param name="query">The instance from which the Entity-SQL command text should be retrieved</param>
/// <returns>The Entity-SQL command text, if the specified query state instance is based on Entity-SQL</returns>
/// <exception cref="NotSupportedException">
/// If the specified instance is not based on Entity-SQL command text, and so does not support Entity-SQL query builder methods
/// </exception>
private static string GetCommandText(ObjectQueryState query)
{
string commandText = null;
if (!query.TryGetCommandText(out commandText))
{
throw EntityUtil.NotSupported(System.Data.Entity.Strings.ObjectQuery_QueryBuilder_NotSupportedLinqSource);
}
return(commandText);
}
internal static ObjectQueryState Top(ObjectQueryState query, string alias, string count, ObjectParameter[] parameters)
{
int queryLength = count.Length;
string queryText = GetCommandText(query);
bool limitAllowed = ((EntitySqlQueryState)query).AllowsLimitSubclause;
if (limitAllowed)
{
// Build the new query string:
// <this query> LIMIT <count>
queryLength += (queryText.Length +
_limitOp.Length
// + count.Length is added above
);
}
else
{
// Build the new query string:
// "SELECT VALUE TOP(<count>) <alias> FROM (<this query>) AS <alias>"
queryLength += (_topOp.Length +
// count.Length + is added above
_topInfix.Length +
alias.Length +
_fromOp.Length +
queryText.Length +
_asOp.Length +
alias.Length);
}
StringBuilder builder = new StringBuilder(queryLength);
if (limitAllowed)
{
builder.Append(queryText);
builder.Append(_limitOp);
builder.Append(count);
}
else
{
builder.Append(_topOp);
builder.Append(count);
builder.Append(_topInfix);
builder.Append(alias);
builder.Append(_fromOp);
builder.Append(queryText);
builder.Append(_asOp);
builder.Append(alias);
}
// Create a new EntitySqlQueryImplementation that uses the new query as its command text.
// Span is carried over, no adjustment is needed.
return(NewBuilderQuery(query, query.ElementType, builder, query.Span, MergeParameters(query.ObjectContext, query.Parameters, parameters)));
}
internal static ObjectQueryState Distinct(ObjectQueryState query)
{
// Build the new query string - "SET(<this query>)"
string queryText = GetCommandText(query);
StringBuilder builder = new StringBuilder(_distinctProlog.Length + queryText.Length + _distinctEpilog.Length);
builder.Append(_distinctProlog);
builder.Append(queryText);
builder.Append(_distinctEpilog);
// Span is carried over, no adjustment is needed
return(NewBuilderQuery(query, query.ElementType, builder, query.Span, ObjectParameterCollection.DeepCopy(query.Parameters)));
}
private static ObjectQueryState BuildOrderByOrWhere(ObjectQueryState query, string alias, string predicateOrKeys, ObjectParameter[] parameters, string op, string skipCount, bool allowsLimit)
{
Debug.Assert(!StringUtil.IsNullOrEmptyOrWhiteSpace(alias), "Invalid alias");
Debug.Assert(!StringUtil.IsNullOrEmptyOrWhiteSpace(predicateOrKeys), "Invalid predicate/keys");
Debug.Assert(null == skipCount || op == _orderByOp, "Skip clause used with WHERE operator?");
string queryText = GetCommandText(query);
// Build the new query string:
// Either: "SELECT VALUE <alias> FROM (<this query>) AS <alias> WHERE <predicate>"
// (for Where)
// Or: "SELECT VALUE <alias> FROM (<this query>) AS <alias> ORDER BY <keys> <optional: SKIP <skip>>"
// Depending on the value of 'op'
int queryLength = _selectValueOp.Length +
alias.Length +
_fromOp.Length +
queryText.Length +
_asOp.Length +
alias.Length +
op.Length +
predicateOrKeys.Length;
if (skipCount != null)
{
queryLength += (_skipOp.Length + skipCount.Length);
}
StringBuilder builder = new StringBuilder(queryLength);
builder.Append(_selectValueOp);
builder.Append(alias);
builder.Append(_fromOp);
builder.Append(queryText);
builder.Append(_asOp);
builder.Append(alias);
builder.Append(op);
builder.Append(predicateOrKeys);
if (skipCount != null)
{
builder.Append(_skipOp);
builder.Append(skipCount);
}
// Create a new EntitySqlQueryImplementation that uses the new query as its command text.
// Span is carried over, no adjustment is needed.
return(NewBuilderQuery(query, query.ElementType, builder, allowsLimit, query.Span, MergeParameters(query.ObjectContext, query.Parameters, parameters)));
}
private static ObjectQueryState NewBuilderQuery(ObjectQueryState sourceQuery, Type elementType, StringBuilder queryText, bool allowsLimit, Span newSpan, IEnumerable <ObjectParameter> enumerableParams)
{
ObjectParameterCollection queryParams = enumerableParams as ObjectParameterCollection;
if (queryParams == null && enumerableParams != null)
{
queryParams = new ObjectParameterCollection(sourceQuery.ObjectContext.Perspective);
foreach (ObjectParameter objectParam in enumerableParams)
{
queryParams.Add(objectParam);
}
}
EntitySqlQueryState newState = new EntitySqlQueryState(elementType, queryText.ToString(), allowsLimit, sourceQuery.ObjectContext, queryParams, newSpan);
sourceQuery.ApplySettingsTo(newState);
return(newState);
}
internal static ObjectQueryState Where(ObjectQueryState query, string alias, string predicate, ObjectParameter[] parameters)
{
return(BuildOrderByOrWhere(query, alias, predicate, parameters, _whereOp, null, false));
}
private static ObjectQueryState NewBuilderQuery(ObjectQueryState sourceQuery, Type elementType, StringBuilder queryText, Span newSpan, IEnumerable <ObjectParameter> enumerableParams)
{
return(NewBuilderQuery(sourceQuery, elementType, queryText, false, newSpan, enumerableParams));
}
internal static ObjectQueryState Skip(ObjectQueryState query, string alias, string keys, string count, ObjectParameter[] parameters)
{
Debug.Assert(!StringUtil.IsNullOrEmptyOrWhiteSpace(count), "Invalid skip count");
return(BuildOrderByOrWhere(query, alias, keys, parameters, _orderByOp, count, true));
}
internal static ObjectQueryState SelectValue(ObjectQueryState query, string alias, string projection, ObjectParameter[] parameters, Type projectedType)
{
return(BuildSelectOrSelectValue(query, alias, projection, parameters, _selectValueOp, projectedType));
}
internal static ObjectQueryState Select(ObjectQueryState query, string alias, string projection, ObjectParameter[] parameters)
{
return(BuildSelectOrSelectValue(query, alias, projection, parameters, _selectOp, typeof(DbDataRecord)));
}
internal static ObjectQueryState OrderBy(ObjectQueryState query, string alias, string keys, ObjectParameter[] parameters)
{
return(BuildOrderByOrWhere(query, alias, keys, parameters, _orderByOp, null, true));
}
internal static ObjectQueryState Except(ObjectQueryState leftQuery, ObjectQueryState rightQuery)
{
// Call the SetOp helper.
// Span is taken from the leftmost query.
return(EntitySqlQueryBuilder.BuildSetOp(leftQuery, rightQuery, leftQuery.Span, _exceptOp));
}
