public bool TryCreateKeyInfo <TEntity, TKey>(
Expression <Func <TEntity, TKey> > keySelector,
out IKeyInfo <TEntity, TKey> result)
where TEntity : class
{
Expression body = keySelector.Body;
Type keyType = body.Type;
if (!typeof(DataRow).IsAssignableFrom(body.Type))
{
result = null;
return(false);
}
IKeyInfoHelper helper = DataRowKeyInfo <TEntity, TKey> .KeyInfoHelper;
MemberInfo[] keyMembers;
if (!helper.TryParseKeySelectorExpression(keySelector.Body, true, out keyMembers))
{
result = null;
return(false);
}
result = new DataRowKeyInfo <TEntity, TKey>(keyMembers);
return(true);
}
private static MemberInfo[] ParseSelector(
Expression <Func <TEntity, TKey> > selector,
IKeyInfoHelper helper)
{
if (!helper.TryParseKeySelectorExpression(
selector.Body,
true,
out MemberInfo[] result))
public bool TryCreateKeyInfo <TEntity, TKey>(
Expression <Func <TEntity, TKey> > keySelector,
out IKeyInfo <TEntity, TKey> result) where TEntity : class
{
if (!ValidateType(typeof(TKey)))
{
result = null;
return(false);
}
IKeyInfoHelper helper = PrimitiveKeyInfo <TEntity, TKey> .KeyInfoHelper;
if (!helper.TryParseKeySelectorExpression(keySelector.Body, true, out MemberInfo[] members))
private static MemberInfo[] ParseSelector(
Expression <Func <TEntity, TKey> > selector,
IKeyInfoHelper helper)
{
MemberInfo[] result = null;
if (!helper.TryParseKeySelectorExpression(
selector.Body,
true,
out result))
{
throw new ArgumentException(
ExceptionMessages.InvalidKeySelector,
"keySelector");
}
return(result);
}
protected override Expression VisitMethodCall(MethodCallExpression node)
{
if (!node.Method.IsGenericMethod ||
node.Method.GetGenericMethodDefinition() != this.Original)
{
// Not GroupJoin
return(base.VisitMethodCall(node));
}
if (!(node.Arguments[1] is ConstantExpression secondExpression))
{
// Not constant expression
return(base.VisitMethodCall(node));
}
if (!(secondExpression.Value is ITable table))
{
// Not table
return(base.VisitMethodCall(node));
}
LambdaExpression secondKeySelector =
ExpressionHelper.SkipQuoteNode(node.Arguments[3]) as LambdaExpression;
Type keyType = secondKeySelector.Body.Type;
IKeyInfoHelper helper = this.GetKeyInfoHelper(keyType);
if (helper == null)
{
// Cannot detect key type
return(base.VisitMethodCall(node));
}
// Try to parse expression
if (!helper.TryParseKeySelectorExpression(
secondKeySelector.Body,
false,
out MemberInfo[] keyMembers))
public bool TryCreateKeyInfo <TEntity, TKey>(
Expression <Func <TEntity, TKey> > keySelector,
out IKeyInfo <TEntity, TKey> result) where TEntity : class
{
if (!ReflectionHelper.IsAnonymousType(typeof(TKey)))
{
result = null;
return(false);
}
IKeyInfoHelper helper = AnonymousTypeKeyInfo <TEntity, TKey> .KeyInfoHelper;
MemberInfo[] members;
if (!helper.TryParseKeySelectorExpression(keySelector.Body, true, out members))
{
result = null;
return(false);
}
result = new AnonymousTypeKeyInfo <TEntity, TKey>(members);
return(true);
}
protected override Expression VisitMethodCall(MethodCallExpression node)
{
if (!node.Method.IsGenericMethod ||
node.Method.GetGenericMethodDefinition() != this.Original)
{
// Not GroupJoin
return(base.VisitMethodCall(node));
}
ConstantExpression secondExpression = node.Arguments[1] as ConstantExpression;
if (secondExpression == null)
{
// Not constant expression
return(base.VisitMethodCall(node));
}
ITable table = secondExpression.Value as ITable;
if (table == null)
{
// Not table
return(base.VisitMethodCall(node));
}
LambdaExpression secondKeySelector =
ExpressionHelper.SkipQuoteNode(node.Arguments[3]) as LambdaExpression;
Type keyType = secondKeySelector.Body.Type;
IKeyInfoHelper helper = this.GetKeyInfoHelper(keyType);
if (helper == null)
{
// Cannot detect key type
return(base.VisitMethodCall(node));
}
// Try to parse expression
MemberInfo[] keyMembers;
if (!helper.TryParseKeySelectorExpression(
secondKeySelector.Body,
false,
out keyMembers))
{
// Cannot parse key
return(base.VisitMethodCall(node));
}
IIndex matchedIndex = null;
int[] mapping = null;
foreach (IIndex index in table.Indexes)
{
if (KeyExpressionHelper.TryGetMemberMapping(
index.KeyInfo.EntityKeyMembers,
keyMembers,
out mapping))
{
matchedIndex = index;
break;
}
}
if (matchedIndex == null)
{
// No matched index was found
return(base.VisitMethodCall(node));
}
var indexServices = GetKeyInfoHelper(matchedIndex.KeyInfo);
if (indexServices == null)
{
return(base.VisitMethodCall(node));
}
// Create key converter
ParameterExpression keyConverterParam = Expression.Parameter(keyType, "x");
LambdaExpression keyConverter =
Expression.Lambda(
KeyExpressionHelper.CreateKeyConversionExpression(keyConverterParam, matchedIndex.KeyInfo.EntityKeyMembers, mapping, helper, indexServices),
keyConverterParam);
// Create key emptyness detector
ParameterExpression keyEmptinessDetectorParam = Expression.Parameter(keyType, "x");
LambdaExpression keyEmptinessDetector =
Expression.Lambda(
KeyExpressionHelper.CreateKeyEmptinessDetector(
keyEmptinessDetectorParam,
helper),
keyEmptinessDetectorParam);
Type[] generics = node.Method.GetGenericArguments();
// GroupJoinIndexed call
MethodInfo indexedMethod = this.Indexed
.MakeGenericMethod(
generics[0],
generics[1],
generics[2],
matchedIndex.KeyInfo.KeyType,
generics[3]);
Expression indexedCall =
Expression.Call(
node.Object,
indexedMethod,
this.Visit(node.Arguments[0]),
Expression.Constant(matchedIndex),
ExpressionHelper.SkipQuoteNode(node.Arguments[2]),
keyEmptinessDetector,
keyConverter,
ExpressionHelper.SkipQuoteNode(node.Arguments[4]));
Type elementType = ReflectionHelper.GetElementType(indexedCall.Type);
// AsQueryable call
return(Expression.Call(
null,
QueryMethods.AsQueryable.MakeGenericMethod(elementType),
indexedCall));
}