/// <summary>
/// Materializes the results of the given command.
/// </summary>
/// <param name="command">Command to execute.</param>
/// <param name="commandBehavior">Command behavior to use when executing the command.</param>
/// <returns>Shaped results.</returns>
public IEnumerable <T> Materialize(DbCommand command, CommandBehavior commandBehavior)
{
EnitityUtility.CheckArgumentNotNull(command, "command");
using (command.Connection.CreateConnectionScope())
{
using (DbDataReader reader = command.ExecuteReader(commandBehavior))
{
foreach (T element in this.Materialize(reader))
{
yield return(element);
}
}
}
}
public Expression OptimizeMethodCall(ReadOnlyCollection <string> fieldNames, ParameterExpression recordParameter, MethodCallExpression methodCall)
{
EnitityUtility.CheckArgumentNotNull(fieldNames, "fieldNames");
EnitityUtility.CheckArgumentNotNull(methodCall, "methodCall");
MethodPattern pattern = GetMethodPattern(methodCall);
if (pattern == MethodPattern.Unsupported)
{
// Cannot optimize this method.
return(methodCall);
}
// if the input record (arguments[0]) is not the record parameter, we cannot
// leverage field names to optimize the shaper
if (recordParameter != methodCall.Arguments[0])
{
return(methodCall);
}
Expression ordinalExpression;
if (!TryGetOrdinalExpression(fieldNames, methodCall, pattern, out ordinalExpression))
{
return(methodCall);
}
Type returnType = methodCall.Method.GetGenericArguments().Single();
bool canAssignNull = returnType.IsClass || (returnType.IsGenericType && typeof(Nullable <>) == returnType.GetGenericTypeDefinition());
// argument[0].GetValue(ordinal)
Expression result = Expression.Call(methodCall.Arguments[0], s_getValue, ordinalExpression);
if (canAssignNull)
{
// (returnType)(argument[0].IsDBNull(ordinal) ? null : result)
result = Expression.Condition(
Expression.Call(methodCall.Arguments[0], s_isDBNull, ordinalExpression),
Expression.Constant(null, typeof(object)),
result);
}
// (returnType)result
result = Expression.Convert(result, returnType);
return(result);
}
/// <summary>
/// Materializes rows in the given reader.
/// </summary>
/// <param name="reader">Results to materialize.</param>
/// <returns>Shaped results.</returns>
public IEnumerable <T> Materialize(DbDataReader reader)
{
EnitityUtility.CheckArgumentNotNull(reader, "reader");
bool first = true;
while (reader.Read())
{
if (first)
{
InitializeShaper(reader);
first = false;
}
yield return(this.shaperDelegate(reader));
}
yield break;
}
public static bool IsGenericAssignableFrom(this Type toType, Type fromType, out Type[] genericArguments)
{
EnitityUtility.CheckArgumentNotNull(toType, "toType");
EnitityUtility.CheckArgumentNotNull(fromType, "fromType");
if (!toType.IsGenericTypeDefinition ||
fromType.IsGenericTypeDefinition)
{
// if 'toType' is not generic or 'fromType' is generic, the assignment pattern
// is not matched (e.g. toType<genericArguments>.IsAssignableFrom(fromType)
// cannot be satisfied)
genericArguments = null;
return(false);
}
if (toType.IsInterface)
{
// if the toType is an interface, simply look for the interface implementation in fromType
foreach (Type interfaceCandidate in fromType.GetInterfaces())
{
if (interfaceCandidate.IsGenericType && interfaceCandidate.GetGenericTypeDefinition() == toType)
{
genericArguments = interfaceCandidate.GetGenericArguments();
return(true);
}
}
}
else
{
// if toType is not an interface, check hierarchy for match
while (fromType != null)
{
if (fromType.IsGenericType && fromType.GetGenericTypeDefinition() == toType)
{
genericArguments = fromType.GetGenericArguments();
return(true);
}
fromType = fromType.BaseType;
}
}
genericArguments = null;
return(false);
}
/// <summary>
/// Removes an entity from the EntitySet. The entity will be deleted
/// when ObjectContext.SaveChanges is called.
/// </summary>
/// <param name="entity">Entity to delete.</param>
public void DeleteOnSaveChanges(T entity)
{
EnitityUtility.CheckArgumentNotNull(((object)entity), "entity");
// check that the entity actually exists first
ObjectStateEntry stateEntry;
if (!this.Context.ObjectStateManager.TryGetObjectStateEntry(entity, out stateEntry))
{
//throw new ArgumentException(Messages.UntrackedEntity, "entity");
}
// now check that the entity belongs to the current entity set
if (this.metadata != stateEntry.EntitySet)
{
//throw new ArgumentException(Messages.DeletingFromWrongSet, "entity");
}
this.Context.DeleteObject(entity);
}
/// <summary>
/// Gets key value for a non-compound reference key (e.g. one foreign key component).
/// </summary>
/// <typeparam name="T">EntityReference element type</typeparam>
/// <param name="entityReference">Entity reference.</param>
/// <returns>Key value from entity reference.</returns>
public static object GetKey <T>(this EntityReference <T> entityReference)
where T : class, IEntityWithRelationships
{
EnitityUtility.CheckArgumentNotNull(entityReference, "entityReference");
EntityKey entityKey = entityReference.EntityKey;
if (null == entityKey)
{
if (entityReference.GetTargetEntitySet().ElementType.KeyMembers.Count != 1)
{
//throw new InvalidOperationException(Messages.SimpleKeyOnly);
}
return(null);
}
var entityKeyValues = entityKey.EntityKeyValues;
if (entityKeyValues.Length != 1)
{
//throw new InvalidOperationException(Messages.SimpleKeyOnly);
}
return(entityKeyValues[0].Value);
}
/// <summary>
/// Gets a component of a key value for a (potentially compound) reference key.
/// </summary>
/// <typeparam name="T">EntityReference element type</typeparam>
/// <param name="entityReference">Entity reference.</param>
/// <param name="keyOrdinal">Index of the key component (with respect to the element type's
/// EntityType.KeyMembers).</param>
/// <returns>Key component value from entity reference.</returns>
public static object GetKey <T>(this EntityReference <T> entityReference, int keyOrdinal)
where T : class, IEntityWithRelationships
{
EnitityUtility.CheckArgumentNotNull(entityReference, "entityReference");
if (keyOrdinal < 0)
{
throw new ArgumentOutOfRangeException("keyOrdinal");
}
EntityKey entityKey = entityReference.EntityKey;
if (null == entityKey)
{
if (entityReference.GetTargetEntitySet().ElementType.KeyMembers.Count <= keyOrdinal)
{
throw new ArgumentOutOfRangeException("keyOrdinal");
}
return(null);
}
if (entityKey.EntityKeyValues.Length <= keyOrdinal)
{
throw new ArgumentOutOfRangeException("keyOrdinal");
}
return(entityKey.EntityKeyValues[keyOrdinal].Value);
}
///// <summary>
///// Creates a store command based on the connection used by given object context.
///// </summary>
///// <param name="context">Object context.</param>
///// <param name="commandText">Command text.</param>
///// <param name="parameters">Parameters to pass to the store command.</param>
///// <returns>Store command.</returns>
//public static DbCommand CreateStoreCommand(ObjectContext context, string commandText, params object[] parameters)
//{
// return CreateStoreCommand(context, commandText, CommandType.Text, parameters);
//}
/// <summary>
/// Creates a store command based on the connection used by given object context.
/// </summary>
/// <param name="context">Object context.</param>
/// <param name="commandText">Command text.</param>
/// <param name="commandType">Command type.</param>
/// <param name="parameters">Parameters to pass to the store command.</param>
/// <returns>Store command.</returns>
public static DbCommand CreateStoreCommand(ObjectContext context, string commandText, CommandType commandType, params object[] parameters)
{
EnitityUtility.CheckArgumentNotNull(context, "context");
EntityConnection entityConnection = (EntityConnection)context.Connection;
DbConnection storeConnection = entityConnection.StoreConnection;
DbCommand storeCommand = storeConnection.CreateCommand();
// setup command
storeCommand.CommandText = commandText;
storeCommand.CommandType = commandType;
if (null != parameters)
{
storeCommand.Parameters.AddRange(parameters);
}
// pass through command timeout as appropriate
if (context.CommandTimeout.HasValue)
{
storeCommand.CommandTimeout = context.CommandTimeout.Value;
}
return(storeCommand);
}
/// <summary>
/// Attaches an existing entity to the current entity set.
/// </summary>
/// <param name="entity">Entity to attach.</param>
public void Attach(T entity)
{
EnitityUtility.CheckArgumentNotNull(((object)entity), "entity");
this.Context.AttachTo(this.QualifiedEntitySetName, entity);
}
/// <summary>
/// Tracks a new entity for insertion when ObjectContext.SaveChanges is called.
/// </summary>
/// <param name="entity">Entity to insert.</param>
public void InsertOnSaveChanges(T entity)
{
EnitityUtility.CheckArgumentNotNull(((object)entity), "entity");
this.Context.AddObject(this.QualifiedEntitySetName, entity);
}
/// <summary>
/// Expands all InvocationExpression instances within the given query.
/// </summary>
/// <param name="query">Query to expand.</param>
/// <returns>Expanded query.</returns>
public static IQueryable <TElement> ExpandInvocations <TElement>(this IQueryable <TElement> query)
{
EnitityUtility.CheckArgumentNotNull(query, "query");
return(query.Provider.CreateQuery <TElement>(query.Expression.ExpandInvocations()));
}
/// <summary>
/// Returns a handle on an IDisposable that can be used to safely control the lifetime
/// of an open connection. If the connection is closed, it will be opened immediately
/// and closed when the result of this method (the scope) is disposed. If the connection is already
/// open, it remains open.
/// <code>
/// // Example with CreateConnectionScope
/// using (command.Connection.CreateConnectionScope())
/// {
/// command.ExecuteNonQuery();
/// }
///
/// // Example without
/// bool connectionOpened = command.Connection.State == ConnectionState.Closed;
/// if (connectionOpened)
/// {
/// command.Connection.Open();
/// }
/// try
/// {
/// command.ExecuteNonQuery();
/// }
/// finally
/// {
/// if (connectionOpened && command.Connection.State == ConnectionState.Open)
/// {
/// command.Connection.Close();
/// }
/// }
/// </code>
/// </summary>
/// <param name="connection">Connection to open.</param>
/// <returns>Scope closing the connection on dispose.</returns>
public static IDisposable CreateConnectionScope(this DbConnection connection)
{
EnitityUtility.CheckArgumentNotNull(connection, "connection");
return(new OpenConnectionLifetime(connection));
}
