private static async Task ReadAsync <T>(DbContext context, Type type, IList <T> entities, TableInfo tableInfo, Action <decimal> progress, CancellationToken cancellationToken) where T : class
{
Dictionary <string, string> previousPropertyColumnNamesDict = tableInfo.ConfigureBulkReadTableInfo(context);
string providerName = context.Database.ProviderName;
// -- SQL Server --
if (providerName.EndsWith(DbServer.SqlServer.ToString()))
{
await context.Database.ExecuteSqlRawAsync(SqlQueryBuilder.CreateTableCopy(tableInfo.FullTableName, tableInfo.FullTempTableName, tableInfo), cancellationToken).ConfigureAwait(false);
try
{
await InsertAsync(context, type, entities, tableInfo, progress, cancellationToken).ConfigureAwait(false);
tableInfo.PropertyColumnNamesDict = previousPropertyColumnNamesDict;
var sqlQuery = SqlQueryBuilder.SelectJoinTable(tableInfo);
tableInfo.PropertyColumnNamesDict = previousPropertyColumnNamesDict;
List <T> existingEntities;
if (typeof(T) == type)
{
Expression <Func <DbContext, IQueryable <T> > > expression = tableInfo.GetQueryExpression <T>(sqlQuery, false);
var compiled = EF.CompileQuery(expression); // instead using Compiled queries
existingEntities = compiled(context).ToList();
}
else
{
Expression <Func <DbContext, IEnumerable> > expression = tableInfo.GetQueryExpression(type, sqlQuery, false);
var compiled = EF.CompileQuery(expression); // instead using Compiled queries
existingEntities = compiled(context).Cast <T>().ToList();
}
tableInfo.UpdateReadEntities(type, entities, existingEntities);
}
finally
{
if (!tableInfo.BulkConfig.UseTempDB)
{
await context.Database.ExecuteSqlRawAsync(SqlQueryBuilder.DropTable(tableInfo.FullTempTableName), cancellationToken).ConfigureAwait(false);
}
}
}
// -- Sqlite --
else if (providerName.EndsWith(DbServer.Sqlite.ToString()))
{
throw new NotImplementedException();
}
else
{
throw new SqlProviderNotSupportedException(providerName);
}
}