/// <summary>
/// Overridable. Generates an instance of a <see cref="DbDataProviderCommandBuilder{TModel}"/>
/// which builds <see cref="DbCommand"/>s for execution by a vendor-specific
/// <see cref="DbDataProvider"/> instance.
/// </summary>
/// <typeparam name="TModel"></typeparam>
/// <param name="query"></param>
/// <returns></returns>
protected virtual DbDataProviderCommandBuilder <TModel> CreateCommandBuilder <TModel>(DataModelQuery <TModel> query)
where TModel : DataModel
{
var ret = new DbDataProviderCommandBuilder <TModel>(this, query);
return(ret);
}
/// <summary>
/// Overridable. Generates an instance of a <see cref="DbDataProviderCommandBuilder{TModel}"/>
/// which builds <see cref="DbCommand"/>s for execution by a vendor-specific
/// <see cref="DbDataProvider"/> instance.
/// </summary>
/// <typeparam name="TModel"></typeparam>
/// <param name="dataModel"></param>
/// <returns></returns>
protected virtual DbDataProviderCommandBuilder <TModel> CreateCommandBuilder <TModel>(TModel dataModel)
where TModel : DataModel
{
var ret = new DbDataProviderCommandBuilder <TModel>(this, dataModel);
return(ret);
}
/// <summary>
/// Saves the changes that were made to the
/// specified <paramref name="dataModel"/>, within the specified
/// database <paramref name="transactionContext"/>.
/// <remarks>
/// The specified object must have the Deleted property set to true,
/// IsDirty evaluated as true, or IsNew evaluated as true, or else
/// the entity will not be saved.
/// </remarks>
/// </summary>
/// <param name="dataModel"></param>
/// <param name="transactionContext"></param>
public override void SaveModel <TModel>(TModel dataModel, DbTransaction transactionContext)
{
if (!dataModel.IsNew &&
!dataModel.IsDirty &&
!dataModel.MarkDeleted)
{
return;
}
DataModelMap demap = DataModelMap.GetEntityMapping(dataModel.GetType());
DbConnection tmpConn = null;
if (transactionContext == null)
{
tmpConn = CreateAndOpenConnection();
transactionContext = tmpConn.BeginTransaction();
}
try
{
DbDataProviderCommandBuilder <TModel> cmdBuilder = CreateCommandBuilder(dataModel);
using (DbCommand cmd = cmdBuilder.CreateDbCommand(transactionContext))
{
cmd.Transaction = transactionContext;
bool wasNew = dataModel.IsNew;
cmd.ExecuteNonQuery();
if (wasNew)
{
foreach (var field in demap.FieldMappings)
{
DataModelColumnAttribute f = field.Value;
if (f.ReturnAsOutputOnInsert)
{
dataModel[f.TargetMember.Name] = cmd.Parameters[f.InsertParam].Value;
}
}
}
}
}
finally
{
if (tmpConn != null)
{
transactionContext.Commit();
tmpConn.Close();
}
}
}
/// <summary>
/// Loads the first <see cref="DataModel"/> that
/// the specified <paramref name="query"/> finds,
/// within the specified database <paramref name="transactionContext"/>.
/// </summary>
/// <typeparam name="TModel"></typeparam>
/// <param name="query"></param>
/// <param name="transactionContext"></param>
/// <returns></returns>
public override TModel LoadModel <TModel>(DataModelQuery <TModel> query, DbTransaction transactionContext)
{
DbConnection tmpConn = null;
if (transactionContext == null)
{
tmpConn = CreateAndOpenConnection();
transactionContext = tmpConn.BeginTransaction(ProviderDefaults.IsolationLevel);
}
try
{
DbConnection conn = transactionContext.Connection;
DbDataProviderCommandBuilder <TModel> cmdBuilder = CreateCommandBuilder(query);
using (DbCommand cmd = cmdBuilder.CreateDbCommand(transactionContext)) // conn.CreateCommand())
{
cmd.Transaction = transactionContext;
using (DbDataReader dr = cmd.ExecuteReader(cmdBuilder.ExecuteBehavior ?? CommandBehavior.SingleRow))
{
if (dr.Read())
{
var ret = (TModel)Activator.CreateInstance(typeof(TModel));
ret.DataProvider = this;
ret.Load(dr);
return(ret);
}
return(null);
}
}
}
finally
{
if (tmpConn != null)
{
transactionContext.Commit();
tmpConn.Close();
}
}
}
/// <summary>
/// Loads a set of <see cref="DataModel"/> objects
/// using the specified <paramref name="query"/> within the
/// specified database <paramref name="transactionContext"/>.
/// </summary>
/// <typeparam name="TModel"></typeparam>
/// <param name="query"></param>
/// <param name="transactionContext"></param>
/// <returns></returns>
public override DataModelCollection <TModel> LoadModels <TModel>(
DataModelQuery <TModel> query, DbTransaction transactionContext)
{
DataModelMap demap = DataModel.GetMapping <TModel>();
DbConnection tmpConn = null;
if (transactionContext == null)
{
tmpConn = CreateAndOpenConnection();
transactionContext = tmpConn.BeginTransaction(ProviderDefaults.IsolationLevel);
}
DbConnection conn = transactionContext.Connection;
try
{
DbDataProviderCommandBuilder <TModel> cmdBuilder = CreateCommandBuilder(query);
using (DbCommand cmd = cmdBuilder.CreateDbCommand(transactionContext))
{
cmd.Transaction = transactionContext;
using (DbDataReader dr = cmd.ExecuteReader(cmdBuilder.ExecuteBehavior ?? CommandBehavior.Default))
{
var ret = new DataModelCollection <TModel> {
DataProvider = this
};
if (query.Pagination == null ||
query.Pagination.ItemsPerPage == int.MaxValue ||
query.Pagination.ItemsPerPage == 0 ||
cmdBuilder.PaginationIsHandled)
{
while (dr.Read())
{
var obj = (TModel)Activator.CreateInstance(typeof(TModel));
obj.DataProvider = this;
obj.Load(dr);
ret.Add(obj);
}
}
else
{
int start = query.Pagination.Page * query.Pagination.ItemsPerPage -
query.Pagination.ItemsPerPage;
bool eof = false;
for (int i = 0; i < start; i++)
{
if (!dr.Read())
{
eof = true;
break;
}
}
for (int i = 0; i < query.Pagination.ItemsPerPage && !eof; i++)
{
if (!dr.Read())
{
eof = true;
break;
}
var obj = (TModel)Activator.CreateInstance(typeof(TModel));
obj.DataProvider = this;
obj.Load(dr);
ret.Add(obj);
}
}
if (!string.IsNullOrEmpty(demap.TableMapping.SelectManyProcedure) &&
query.OrderBy.Count > 0)
{
// exec sort from last sort field to first to get correct end result
for (int i = query.OrderBy.Count - 1; i >= 0; i--)
{
string fld = query.OrderBy[i].GetFieldMapping(typeof(TModel)).TargetMember.Name;
switch (query.OrderBy[i].SortDirection)
{
case Sort.Ascending:
TModel[] asc = (from item in ret
orderby item[fld] ascending
select item).ToArray();
ret = new DataModelCollection <TModel>(asc);
break;
case Sort.Descending:
TModel[] desc = (from item in ret
orderby item[fld] descending
select item).ToArray();
ret = new DataModelCollection <TModel>(desc);
break;
}
}
}
return(ret);
}
}
}
finally
{
if (tmpConn != null)
{
transactionContext.Commit();
tmpConn.Close();
}
}
}
