/// <summary>
/// Update an entity of Generic Parameter in the corresponding table in the database.
/// </summary>
/// <typeparam name="TBusinessEntity">An Entity type to insert the entity object in.</typeparam>
/// <param name="entity">An entity object to be updated in the table corresponding to Entity type.</param>
/// <returns>New entity object after update it in the database.</returns>
/// <exception cref="BusinessRuleException">When a constraints on database level is voilated due to current UPDATE statement.</exception>
/// <exception cref="RepositoryException">When an error on the database level is occurred and couldn't be recovered.</exception>
public virtual TBusinessEntity Update <TBusinessEntity>(TBusinessEntity entity)
where TBusinessEntity : class, new()
{
try
{
using (ShoppingListContext context = new ShoppingListContext())
{
TBusinessEntity updatedEntity = context.UpdateGraph <TBusinessEntity>(entity);
int erc = context.SaveChanges();
var result = erc > 0 ? updatedEntity : null;
if (result != null)
{
// update the generation
Cache.NextGeneration <TBusinessEntity>();
}
return(result);
}
}
catch (Exception ex)
{
throw ThrowHelper.ReThrow <TBusinessEntity>(ex);
}
}
/// <summary>
/// Delete an entity of Generic Parameter from the corresponding table in the database.
/// </summary>
/// <typeparam name="TBusinessEntity">An Entity type to delete the entity object from.</typeparam>
/// <param name="entity">An entity object to be deleted from the table corresponding to Entity type.</param>
/// <returns>True, if object deleted successfully. False, otherwise.</returns>
/// <exception cref="BusinessRuleException">When a constraints on database level is voilated due to current DELETE statement.</exception>
/// <exception cref="RepositoryException">When an error on the database level is occurred and couldn't be recovered.</exception>
public virtual bool Delete <TBusinessEntity>(TBusinessEntity entity)
where TBusinessEntity : class, new()
{
try
{
using (ShoppingListContext context = new ShoppingListContext())
{
context.Set <TBusinessEntity>().Attach(entity);
context.Set <TBusinessEntity>().Remove(entity);
int erc = context.SaveChanges();
var result = erc > 0;
if (result == true)
{
// update the generation
Cache.NextGeneration <TBusinessEntity>();
}
return(result);
}
}
catch (Exception ex)
{
throw ThrowHelper.ReThrow <TBusinessEntity>(ex);
}
}
/// <summary>
/// Delete entities of Generic Parameter from the corresponding table in the database.
/// </summary>
/// <typeparam name="TBusinessEntity">An Entity type to delete the entity object from.</typeparam>
/// <param name="entities">An entities objects to be deleted from the table corresponding to Entity type.</param>
/// <returns>True, if object deleted successfully. False, otherwise.</returns>
/// <exception cref="BusinessRuleException">When a constraints on database level is voilated due to current DELETE statement.</exception>
/// <exception cref="RepositoryException">When an error on the database level is occurred and couldn't be recovered.</exception>
public bool Delete <TBusinessEntity>(IEnumerable <TBusinessEntity> entities)
where TBusinessEntity : class, new()
{
try
{
using (ShoppingListContext context = new ShoppingListContext())
{
foreach (TBusinessEntity item in entities)
{
var i = context.UpdateGraph(item);
context.Set <TBusinessEntity>().Attach(i);
context.Set <TBusinessEntity>().Remove(i);
}
int erc = context.SaveChanges();
var result = erc > 0;
if (result == true)
{
// update the generation
Cache.NextGeneration <TBusinessEntity>();
}
return(result);
}
}
catch (Exception ex)
{
throw ThrowHelper.ReThrow <TBusinessEntity>(ex);
}
}
/// <summary>
/// Returns single BusinessObject of table that satisfies the given <paramref name="id"/> or a null if no such element is found.
/// </summary>
/// <typeparam name="TBusinessEntity">The type of BusinessObject of source table.</typeparam>
/// <param name="id">Id of the BusinessObject.</param>
/// <returns>BusinessObject the satisfy the <paramref name="id"/>.</returns>
/// <exception cref="RepositoryException">When an error on the database level is occurred and couldn't be recovered.</exception>
public TBusinessEntity SingleOrDefault <TBusinessEntity>(int id)
where TBusinessEntity : class, new()
{
try
{
using (ShoppingListContext context = new ShoppingListContext())
return(context.Set <TBusinessEntity>().Find(id));
}
catch (Exception ex)
{
throw ThrowHelper.ReThrow <TBusinessEntity>(ex);
}
}
/// <summary>
/// Returns record count of table that satisfy the given <paramref name="constraints"/>.
/// </summary>
/// <typeparam name="TBusinessEntity">The type of BusinessObject of source table.</typeparam>
/// <param name="constraints">QueryConstraints object to be satisfied.</param>
/// <returns>The number of elements in the table that satisfies the given <paramref name="constraints"/>.</returns>
/// <exception cref="RepositoryException">When an error on the database level is occurred and couldn't be recovered.</exception>
public int GetCount <TBusinessEntity>(IQueryConstraints <TBusinessEntity> constraints)
where TBusinessEntity : class, new()
{
try
{
using (ShoppingListContext context = new ShoppingListContext())
return(context.Set <TBusinessEntity>()
.Count(constraints.Predicate));
}
catch (Exception ex)
{
throw ThrowHelper.ReThrow <TBusinessEntity>(ex);
}
}
/// <summary>
/// Returns custom graph of single BusinessObject of table that satisfies a specified <see cref="IQueryConstraints{T}"/> or null if no such element is found.
/// </summary>
/// <typeparam name="TBusinessEntity">The type of BusinessObject of source table.</typeparam>
/// <param name="constraints">QueryConstraints object to be satisfied.</param>
/// <returns>BusinessObject the satisfy the <paramref name="constraints"/>.</returns>
/// <exception cref="RepositoryException">When an error on the database level is occurred and couldn't be recovered.</exception>
public TBusinessEntity SingleOrDefault <TBusinessEntity>(IQueryConstraints <TBusinessEntity> constraints)
where TBusinessEntity : class, new()
{
try
{
using (ShoppingListContext context = new ShoppingListContext())
return(context.Set <TBusinessEntity>()
.ToSearchResult <TBusinessEntity>(constraints)
.Items
.FirstOrDefault());
}
catch (Exception ex)
{
throw ThrowHelper.ReThrow <TBusinessEntity>(ex);
}
}
/// <summary>
/// Returns full graph of single BusinessObject of table that satisfies the given <paramref name="id"/> or null if no such element is found.
/// </summary>
/// <typeparam name="TBusinessEntity">The type of BusinessObject of source table.</typeparam>
/// <param name="id">Id of the BusinessObject.</param>
/// <returns>BusinessObject the satisfy the <paramref name="id"/>.</returns>
/// <exception cref="RepositoryException">When an error on the database level is occurred and couldn't be recovered.</exception>
public TBusinessEntity SingleOrDefaultWithGraph <TBusinessEntity>(int id)
where TBusinessEntity : class, new()
{
try
{
using (ShoppingListContext context = new ShoppingListContext())
{
var primaryKeyPredicate = CreatePredicate <TBusinessEntity>(context, id);
return(context.LoadAggregate(primaryKeyPredicate));
}
}
catch (Exception ex)
{
throw ThrowHelper.ReThrow <TBusinessEntity>(ex);
}
}
/// <summary>
/// Returns <see cref="IQueryResult{T}"/> that satisfy the given <paramref name="constraints"/> on the table.
/// </summary>
/// <typeparam name="TBusinessEntity">The type of BusinessObject of source table.</typeparam>
/// <param name="constraints">QueryConstraints object to be satisfied.</param>
/// <returns>The result records that satisfy the given <paramref name="constraints"/>.</returns>
/// <exception cref="RepositoryException">When an error on the database level is occurred and couldn't be recovered.</exception>
public IQueryResult <TBusinessEntity> Find <TBusinessEntity>(IQueryConstraints <TBusinessEntity> constraints)
where TBusinessEntity : class, new()
{
try
{
using (ShoppingListContext context = new ShoppingListContext())
{
IQueryResult <TBusinessEntity> results = null;
// get the appropriate cache key for this query
string key = Cache.CacheKey(constraints);
// check if it's in the cache already
if (!Cache.Provider.TryGet(key, out results))
{
Debug.WriteLine($"NOT FOUND cache for: {key}");
// if not, then run the query
results = context.Set <TBusinessEntity>().ToSearchResult(constraints);
// and cache the results for next time
Cache.Provider.Set(key, results);
}
else
{
Debug.WriteLine($"Found cache for: {key}");
}
// return the results either from cache or that were just run
return(results);
}
}
catch (Exception ex)
{
throw ThrowHelper.ReThrow <TBusinessEntity>(ex);
}
}
private Expression <Func <TBusinessEntity, bool> > CreatePredicate <TBusinessEntity>(ShoppingListContext context, int id)
{
var entityType = typeof(TBusinessEntity);
var metadata = ((IObjectContextAdapter)context).ObjectContext.MetadataWorkspace
.GetItems <EntityType>(DataSpace.OSpace)
.SingleOrDefault(p => p.FullName == entityType.FullName);
if (metadata == null)
{
throw new InvalidOperationException($"The type {entityType.FullName} is not known to the DbContext.");
}
var keyProperties = metadata.KeyMembers
.Select(k => entityType.GetProperty(k.Name, BindingFlags.Instance | BindingFlags.NonPublic | BindingFlags.Public))
.ToList();
ParameterExpression parameter = Expression.Parameter(entityType);
Expression expression = CreateEqualsExpression(id, keyProperties[0], parameter);
//for (int i = 1; i < keyProperties.Count; i++)
//{
// expression = Expression.And(expression, CreateEqualsExpression(entity, keyProperties[i], parameter));
//}
return(Expression.Lambda <Func <TBusinessEntity, bool> >(expression, parameter));
}