private static IShardingRouteEngine GetDALRoutingEngine(ShardingRule shardingRule, ISqlCommand sqlCommand, ICollection <String> tableNames)
 {
     if (sqlCommand is UseCommand)
     {
         return(new ShardingIgnoreRoutingEngine());
     }
     if (sqlCommand is SetCommand || sqlCommand is ResetParameterCommand || sqlCommand is ShowDatabasesCommand)
     {
         return(new ShardingDatabaseBroadcastRoutingEngine());
     }
     if (tableNames.Any() && !shardingRule.TableRuleExists(tableNames) && shardingRule.HasDefaultDataSourceName())
     {
         return(new ShardingDefaultDatabaseRoutingEngine(tableNames));
     }
     if (tableNames.Any())
     {
         return(new ShardingUnicastRoutingEngine(tableNames));
     }
     return(new ShardingDataSourceGroupBroadcastRoutingEngine());
 }
        public static IShardingRouteEngine NewInstance(ShardingRule shardingRule,
                                                       ShardingConnectorMetaData metaData, ISqlCommandContext <ISqlCommand> sqlCommandContext,
                                                       ShardingConditions shardingConditions, ConfigurationProperties properties)
        {
            var sqlStatement = sqlCommandContext.GetSqlCommand();
            ICollection <String> tableNames = sqlCommandContext.GetTablesContext().GetTableNames();

            if (sqlStatement is TCLCommand)
            {
                return(new ShardingDatabaseBroadcastRoutingEngine());
            }
            if (sqlStatement is DDLCommand)
            {
                return(new ShardingTableBroadcastRoutingEngine(metaData.Schema, sqlCommandContext));
            }
            if (sqlStatement is DALCommand)
            {
                return(GetDALRoutingEngine(shardingRule, sqlStatement, tableNames));
            }
            if (sqlStatement is DCLCommand)
            {
                return(GetDCLRoutingEngine(sqlCommandContext, metaData));
            }
            if (shardingRule.IsAllInDefaultDataSource(tableNames))
            {
                return(new ShardingDefaultDatabaseRoutingEngine(tableNames));
            }
            if (shardingRule.IsAllBroadcastTables(tableNames))
            {
                if (sqlStatement is SelectCommand)
                {
                    return(new ShardingUnicastRoutingEngine(tableNames));
                }
                return(new ShardingDatabaseBroadcastRoutingEngine());
            }
            if (sqlCommandContext.GetSqlCommand() is DMLCommand && tableNames.IsEmpty() && shardingRule.HasDefaultDataSourceName())
            {
                return(new ShardingDefaultDatabaseRoutingEngine(tableNames));
            }
            if (sqlCommandContext.GetSqlCommand() is DMLCommand && shardingConditions.IsAlwaysFalse() || tableNames.IsEmpty() || !shardingRule.TableRuleExists(tableNames))
            {
                return(new ShardingUnicastRoutingEngine(tableNames));
            }
            return(GetShardingRoutingEngine(shardingRule, sqlCommandContext, shardingConditions, tableNames, properties));
        }