internal static int CommitTransaction <TEntity>(DbContext context, IEnumerable <TEntity> entities, OperationType operation) where TEntity : class
{
// Retrieve entity type
IEntityType entityType = context.Model.FindEntityType(typeof(TEntity));
EntityInfo entityMapping = new EntityInfo(entityType);
// Sample random table looks like this [_VssBuildDefinition_02da3b]
string randomTableName = $"[_{entityMapping.TableName}_{Guid.NewGuid().ToString().Substring(0, 6)}]";
// Build staging table sql command
string stagingTableCommand = BulkOperationHelper.BuildStagingTableCommand(entityMapping, randomTableName, operation);
// Open connection if it's closed
if (context.Database.GetDbConnection().State == ConnectionState.Closed)
{
context.Database.GetDbConnection().Open();
}
// If caller does not specify a transaction we create an internal transaction
IDbContextTransaction internalTrasaction = null;
if (context.Database.CurrentTransaction == null)
{
internalTrasaction = context.Database.BeginTransaction();
}
// No entities to commit
if (!entities.Any())
{
return(0);
}
// Final step is to create staging table and merge data into final table
try
{
// Create staging table and insert data into staging table
BulkOperationHelper.ExecuteSqlCommandNonQuery(context, stagingTableCommand);
BulkOperationHelper.BulkInsertToTable(entityMapping, context, entities.ToList(), randomTableName, operation);
// Merge staging table data into final table and commit
string mergeCommand = BulkOperationHelper.BuildMergeCommand(entityMapping, randomTableName, operation);
int result = BulkOperationHelper.ExecuteSqlCommandNonQuery(context, mergeCommand);
// Only commit internal transaction and let caller's transaction commit on their own
internalTrasaction?.Commit();
// Return the number of records affected
return(result);
}
catch (Exception)
{
// If anything goes wrong, we roll back to undo the operation
internalTrasaction?.Rollback();
context.Database.CurrentTransaction?.GetDbTransaction().Rollback();
throw;
}
}