public void InitBuilder(
EntityInfo entityInfo,
Func <Type, NpgsqlDataReader, string, object> readerFunc)
{
var name = NpgsqlBulkUploader.GetUniqueName(typeof(T).Name);
assemblyName = new AssemblyName {
Name = name
};
assemblyBuilder = AssemblyBuilder.DefineDynamicAssembly(
assemblyName, AssemblyBuilderAccess.Run);
moduleBuilder = assemblyBuilder.DefineDynamicModule(name);
typeBuilder = moduleBuilder.DefineType(name, TypeAttributes.Public);
GenerateWriteCode(entityInfo, readerFunc);
}
public static List <T> BulkSelect <T, TKey>(
this IQueryable <T> source,
Expression <Func <T, TKey> > keyExpression,
IEnumerable <TKey> keyData)
{
EnsureNoNavigationProperties(keyExpression);
BulkSelectInterceptor.StartInterception();
var keyDataTable = NpgsqlBulkUploader.GetUniqueName("_schema_");
var schemaQuery = source.Select(keyExpression);
var schemaSql = $"CREATE TEMP TABLE {keyDataTable} ON COMMIT DROP AS ({schemaQuery} LIMIT 0)";
var context = NpgsqlHelper.GetContextFromQuery(source);
var conn = NpgsqlHelper.GetNpgsqlConnection(context);
var localTr = NpgsqlHelper.EnsureOrStartTransaction(context, IsolationLevel.ReadCommitted);
try
{
context.Database.ExecuteSqlCommand(schemaSql);
var columnsInfo = NpgsqlHelper.GetColumnsInfo(context, keyDataTable);
var propsMap = GetPropertiesMap(
((IObjectContextAdapter)context).ObjectContext,
schemaQuery.Expression,
typeof(TKey));
var mapsInfo = new List <MappingInfo>();
foreach (var propMap in propsMap)
{
var cinfo = columnsInfo[propMap.Item2];
mapsInfo.Add(new MappingInfo()
{
Property = propMap.Item1,
ColumnInfo = cinfo,
NpgsqlType = NpgsqlBulkUploader.GetNpgsqlType(cinfo)
});
}
var columnsCsv = string.Join(", ",
mapsInfo.Select(x => NpgsqlHelper.GetQualifiedName(x.ColumnInfo.ColumnName)));
var copySql = $"COPY {keyDataTable} ({columnsCsv}) FROM STDIN (FORMAT BINARY)";
using (var importer = conn.BeginBinaryImport(copySql))
{
foreach (var kd in keyData)
{
importer.StartRow();
foreach (var kp in mapsInfo)
{
importer.Write(kp.Property.GetValue(kd), kp.NpgsqlType);
}
}
importer.Complete();
}
var whereSql = string.Join(" AND ",
mapsInfo.Select(x =>
{
var sourceColumn = NpgsqlHelper.GetQualifiedName(x.ColumnInfo.ColumnName);
var targetColumn = NpgsqlHelper.GetQualifiedName(x.ColumnInfo.ColumnName);
var clause = $"source.{sourceColumn} = {keyDataTable}.{targetColumn}";
if (x.IsNullableInClr)
{
clause = $"({clause} OR (source.{sourceColumn} IS NULL AND {keyDataTable}.{targetColumn} IS NULL))";
}
return(clause);
}));
var selectSql = $"SELECT source.* FROM ({source}) as source\n" +
$"JOIN {keyDataTable} ON {whereSql}";
BulkSelectInterceptor.SetReplaceQuery(source.ToString(), selectSql);
var result = source.ToList();
localTr?.Commit();
return(result);
}
catch
{
localTr?.Rollback();
throw;
}
finally
{
BulkSelectInterceptor.StopInterception();
}
}