no mycat database selected

url=jdbc:mysql://127.0.0.1:3306?useUnicode=true&characterEncoding=UTF-8&zeroDateTimeBehavior=convertToNull&allowMultiQueries=true

url=jdbc:mysql://127.0.0.1:3306/voole_sysmgr?useUnicode=true&characterEncoding=UTF-8&zeroDateTimeBehavior=convertToNull&allowMultiQueries=true

public void execute(String sql, int type) {
		// 连接状态检查
		if (this.isClosed()) {
			LOGGER.warn("ignore execute ,server connection is closed " + this);
			return;
		}
		// 事务状态检查
		if (txInterrupted) {
			writeErrMessage(ErrorCode.ER_YES, "Transaction error, need to rollback." + txInterrputMsg);
			return;
		}

		// 检查当前使用的DB        //@1
		String db = this.schema;
		boolean isDefault = true;
		if (db == null) {
			db = SchemaUtil.detectDefaultDb(sql, type);
			if (db == null) {
				writeErrMessage(ErrorCode.ERR_BAD_LOGICDB, "No MyCAT Database selected");
				return;
			}
			isDefault = false;
		}

                // @2 start 
		// 兼容PhpAdmin's, 支持对MySQL元数据的模拟返回
		 TODO: 2016/5/20 支持更多information_schema特性
		if (ServerParse.SELECT == type && db.equalsIgnoreCase("information_schema")) {
			MysqlInformationSchemaHandler.handle(sql, this);
			return;
		}

		if (ServerParse.SELECT == type && sql.contains("mysql") && sql.contains("proc")) {

			SchemaUtil.SchemaInfo schemaInfo = SchemaUtil.parseSchema(sql);
			if (schemaInfo != null && "mysql".equalsIgnoreCase(schemaInfo.schema)
					&& "proc".equalsIgnoreCase(schemaInfo.table)) {

				// 兼容MySQLWorkbench
				MysqlProcHandler.handle(sql, this);
				return;
			}
		}

		SchemaConfig schema = MycatServer.getInstance().getConfig().getSchemas().get(db);
		if (schema == null) {
			writeErrMessage(ErrorCode.ERR_BAD_LOGICDB, "Unknown MyCAT Database '" + db + "'");
			return;
		}

		// fix navicat SELECT STATE AS `State`, ROUND(SUM(DURATION),7) AS
		// `Duration`, CONCAT(ROUND(SUM(DURATION)/*100,3), '%') AS `Percentage`
		// FROM INFORMATION_SCHEMA.PROFILING WHERE QUERY_ID= GROUP BY STATE
		// ORDER BY SEQ
		if (ServerParse.SELECT == type && sql.contains(" INFORMATION_SCHEMA.PROFILING ")
				&& sql.contains("CONCAT(ROUND(SUM(DURATION)/")) {
			InformationSchemaProfiling.response(this);
			return;
		}  //@2 end

		/*
		 * 当已经设置默认schema时，可以通过在sql中指定其它schema的方式执行 相关sql，已经在mysql客户端中验证。
		 * 所以在此处增加关于sql中指定Schema方式的支持。
		 */
		if (isDefault && schema.isCheckSQLSchema() && isNormalSql(type)) {
			SchemaUtil.SchemaInfo schemaInfo = SchemaUtil.parseSchema(sql);
			if (schemaInfo != null && schemaInfo.schema != null && !schemaInfo.schema.equals(db)) {
				SchemaConfig schemaConfig = MycatServer.getInstance().getConfig().getSchemas().get(schemaInfo.schema);
				if (schemaConfig != null)
					schema = schemaConfig;
			}
		}    //@3

		routeEndExecuteSQL(sql, type, schema);   //@4

	}