python - sqlalchemy 有没有办法使用预先存在的数据库生成模型？

Question

这个问题已经有答案了:

SQLAlchemy: Auto generate class definitions for a legacy database (1 个回答)

已关闭 5 年前。

我正在分析我所在大学的能源数据。他们给了我们两个文件。

./00_schema.sql

-- MySQL dump 10.13  Distrib 5.5.40, for debian-linux-gnu (i686)
--
-- Host: ########    Database: power
-- ------------------------------------------------------
-- Server version   5.5.35-0ubuntu0.12.04.2

/*!40101 SET @OLD_CHARACTER_SET_CLIENT=@@CHARACTER_SET_CLIENT */;
/*!40101 SET @OLD_CHARACTER_SET_RESULTS=@@CHARACTER_SET_RESULTS */;
/*!40101 SET @OLD_COLLATION_CONNECTION=@@COLLATION_CONNECTION */;
/*!40101 SET NAMES utf8 */;
/*!40103 SET @OLD_TIME_ZONE=@@TIME_ZONE */;
/*!40103 SET TIME_ZONE='+00:00' */;
/*!40014 SET @OLD_UNIQUE_CHECKS=@@UNIQUE_CHECKS, UNIQUE_CHECKS=0 */;
/*!40014 SET @OLD_FOREIGN_KEY_CHECKS=@@FOREIGN_KEY_CHECKS, FOREIGN_KEY_CHECKS=0 */;
/*!40101 SET @OLD_SQL_MODE=@@SQL_MODE, SQL_MODE='NO_AUTO_VALUE_ON_ZERO' */;
/*!40111 SET @OLD_SQL_NOTES=@@SQL_NOTES, SQL_NOTES=0 */;

--
-- Table structure for table `device_description`
--

DROP TABLE IF EXISTS `device_description`;
/*!40101 SET @saved_cs_client     = @@character_set_client */;
/*!40101 SET character_set_client = utf8 */;
CREATE TABLE `device_description` (
  `dd_id` int(11) NOT NULL AUTO_INCREMENT,
  `dd_host_name` varchar(64) NOT NULL,
  `dd_dev_name` varchar(64) NOT NULL,
  `dd_dev_id` int(11) NOT NULL,
  PRIMARY KEY (`dd_id`),
  KEY `host_TO_Device_idx` (`dd_host_name`)
) ENGINE=InnoDB AUTO_INCREMENT=20 DEFAULT CHARSET=utf32 COMMENT='Device Name to device id definitions';
/*!40101 SET character_set_client = @saved_cs_client */;

--
-- Table structure for table `host_description`
--

DROP TABLE IF EXISTS `host_description`;
/*!40101 SET @saved_cs_client     = @@character_set_client */;
/*!40101 SET character_set_client = utf8 */;
CREATE TABLE `host_description` (
  `host_id` int(11) NOT NULL,
  `host_name` varchar(64) NOT NULL,
  `host_ip` varchar(15) NOT NULL,
  PRIMARY KEY (`host_id`)
) ENGINE=InnoDB DEFAULT CHARSET=utf32 COMMENT='Host to host_id definitions';
/*!40101 SET character_set_client = @saved_cs_client */;

--
-- Table structure for table `measurement_description`
--

DROP TABLE IF EXISTS `measurement_description`;
/*!40101 SET @saved_cs_client     = @@character_set_client */;
/*!40101 SET character_set_client = utf8 */;
CREATE TABLE `measurement_description` (
  `meas_id` int(11) NOT NULL,
  `meas_name` varchar(64) DEFAULT NULL,
  PRIMARY KEY (`meas_id`)
) ENGINE=InnoDB DEFAULT CHARSET=utf32 COMMENT='Measurement to measurement_id definitions';
/*!40101 SET character_set_client = @saved_cs_client */;

--
-- Table structure for table `tuc_power_measurements`
--

DROP TABLE IF EXISTS `tuc_power_measurements`;
/*!40101 SET @saved_cs_client     = @@character_set_client */;
/*!40101 SET character_set_client = utf8 */;
CREATE TABLE `tuc_power_measurements` (
  `pm_id` int(11) NOT NULL AUTO_INCREMENT,
  `pm_host_id` int(11) NOT NULL,
  `pm_dev_id` int(11) NOT NULL,
  `pm_meas_id` int(11) NOT NULL,
  `pm_meas_value` decimal(12,6) NOT NULL,
  `pm_meas_timestamp` timestamp NOT NULL DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP,
  PRIMARY KEY (`pm_id`),
  KEY `pm_host_To_host_descr_idx` (`pm_host_id`),
  KEY `pm_dev_To_dev_descr_idx` (`pm_dev_id`),
  KEY `pm_meas_To_meas_descr_idx` (`pm_meas_id`),
  KEY `pm_meas_timestamp` (`pm_meas_timestamp`),
  CONSTRAINT `pm_host_To_host_descr` FOREIGN KEY (`pm_host_id`) REFERENCES `host_description` (`host_id`) ON DELETE NO ACTION ON UPDATE NO ACTION,
  CONSTRAINT `pm_meas_To_meas_descr` FOREIGN KEY (`pm_meas_id`) REFERENCES `measurement_description` (`meas_id`) ON DELETE NO ACTION ON UPDATE NO ACTION
) ENGINE=InnoDB AUTO_INCREMENT=9409956 DEFAULT CHARSET=utf32;
/*!40101 SET character_set_client = @saved_cs_client */;
/*!40103 SET TIME_ZONE=@OLD_TIME_ZONE */;

/*!40101 SET SQL_MODE=@OLD_SQL_MODE */;
/*!40014 SET FOREIGN_KEY_CHECKS=@OLD_FOREIGN_KEY_CHECKS */;
/*!40014 SET UNIQUE_CHECKS=@OLD_UNIQUE_CHECKS */;
/*!40101 SET CHARACTER_SET_CLIENT=@OLD_CHARACTER_SET_CLIENT */;
/*!40101 SET CHARACTER_SET_RESULTS=@OLD_CHARACTER_SET_RESULTS */;
/*!40101 SET COLLATION_CONNECTION=@OLD_COLLATION_CONNECTION */;
/*!40111 SET SQL_NOTES=@OLD_SQL_NOTES */;

-- Dump completed on 2014-12-15 10:14:10

./00_basedata.sql

-- MySQL dump 10.13  Distrib 5.5.40, for debian-linux-gnu (i686)
--
-- Host: ######   Database: power
-- ------------------------------------------------------
-- Server version   5.5.35-0ubuntu0.12.04.2

/*!40101 SET @OLD_CHARACTER_SET_CLIENT=@@CHARACTER_SET_CLIENT */;
/*!40101 SET @OLD_CHARACTER_SET_RESULTS=@@CHARACTER_SET_RESULTS */;
/*!40101 SET @OLD_COLLATION_CONNECTION=@@COLLATION_CONNECTION */;
/*!40101 SET NAMES utf8 */;
/*!40103 SET @OLD_TIME_ZONE=@@TIME_ZONE */;
/*!40103 SET TIME_ZONE='+00:00' */;
/*!40014 SET @OLD_UNIQUE_CHECKS=@@UNIQUE_CHECKS, UNIQUE_CHECKS=0 */;
/*!40014 SET @OLD_FOREIGN_KEY_CHECKS=@@FOREIGN_KEY_CHECKS, FOREIGN_KEY_CHECKS=0 */;
/*!40101 SET @OLD_SQL_MODE=@@SQL_MODE, SQL_MODE='NO_AUTO_VALUE_ON_ZERO' */;
/*!40111 SET @OLD_SQL_NOTES=@@SQL_NOTES, SQL_NOTES=0 */;

--
-- Dumping data for table `device_description`
--

LOCK TABLES `device_description` WRITE;
/*!40000 ALTER TABLE `device_description` DISABLE KEYS */;
INSERT INTO `device_description` VALUES (1,'powerMeter-ARXE','Transformer 1',1),(2,'powerMeter-ARXE','Transformer 2',2),(3,'powerMeter-ARXE','D1 DEH',3),(4,'powerMeter-ARXE','D1 Generator',4),(5,'powerMeter-ARXE','A1 DataCenter',5),(6,'powerMeter-RESTAURANT','Restaurant',1),(7,'powerMeter-M1A','MHXOP 1',1),(8,'powerMeter-M1A','MHXOP 2',2),(9,'powerMeter-M1A','MHPER A - DEH',3),(10,'powerMeter-M1A','MHPER A - Generator',4),(11,'powerMeter-L1A','MHPER B - DEH',1),(12,'powerMeter-L1A','MHPER B - Generator',2),(13,'powerMeter-L1A','Transformer 1',3),(14,'powerMeter-L1A','Transformer 2',4),(15,'powerMeter-H1A','ESTIA',1),(16,'powerMeter-Z1A','GYM',1),(17,'powerMeter-D4A','MPD - DEH',1),(19,'powerMeter-D4A','MPD - Generator',2);
/*!40000 ALTER TABLE `device_description` ENABLE KEYS */;
UNLOCK TABLES;

--
-- Dumping data for table `host_description`
--

LOCK TABLES `host_description` WRITE;
/*!40000 ALTER TABLE `host_description` DISABLE KEYS */;
INSERT INTO `host_description` VALUES (1,'powerMeter-ARXE','147.27.245.11'),(2,'powerMeter-D4A','147.27.245.18'),(3,'powerMeter-H1A','147.27.245.16'),(4,'powerMeter-Z1A','147.27.245.17'),(5,'powerMeter-L1A','147.27.245.15'),(6,'powerMeter-M1A','147.27.245.13'),(7,'powerMeter-RESTAURANT','147.27.245.12');
/*!40000 ALTER TABLE `host_description` ENABLE KEYS */;
UNLOCK TABLES;

--
-- Dumping data for table `measurement_description`
--

LOCK TABLES `measurement_description` WRITE;
/*!40000 ALTER TABLE `measurement_description` DISABLE KEYS */;
INSERT INTO `measurement_description` VALUES (1,'Power Active - total'),(2,'Power Factor - average'),(3,'Frequency - Hz'),(4,'Current phase 1 to Neutral'),(5,'Current phase 2 to Neutral'),(6,'Current phase 3 to Neutral'),(7,'Voltage phase 1 to Neutral'),(8,'Voltage phase 2 to Neutral'),(9,'Voltage phase 3 to Neutral');
/*!40000 ALTER TABLE `measurement_description` ENABLE KEYS */;
UNLOCK TABLES;
/*!40103 SET TIME_ZONE=@OLD_TIME_ZONE */;

/*!40101 SET SQL_MODE=@OLD_SQL_MODE */;
/*!40014 SET FOREIGN_KEY_CHECKS=@OLD_FOREIGN_KEY_CHECKS */;
/*!40014 SET UNIQUE_CHECKS=@OLD_UNIQUE_CHECKS */;
/*!40101 SET CHARACTER_SET_CLIENT=@OLD_CHARACTER_SET_CLIENT */;
/*!40101 SET CHARACTER_SET_RESULTS=@OLD_CHARACTER_SET_RESULTS */;
/*!40101 SET COLLATION_CONNECTION=@OLD_COLLATION_CONNECTION */;
/*!40111 SET SQL_NOTES=@OLD_SQL_NOTES */;

-- Dump completed on 2014-12-15 10:15:47

然后我运行命令:

mysql -uroot -p -e "DROP DATABASE IF EXISTS power;"
mysql -uroot -p -e 'create database power;'
mysql -uroot -p power <  mysql_functions_procedures_etc/00_schema.sql
mysql -uroot -p power < mysql_functions_procedures_etc/00_basedata.sql

一切都好。我还用 mysql workbench 检查了它。

1. 如何在不定义 db.Model 的情况下将 sqlalchemy 连接到它？ (我知道如何通过在 Flask 中处理 Web 应用程序来定义模型等)

2. 我想使用 orm。

3. 或者，如果不定义模型就不可能，是否有办法提取 结构并将模型从 mysql 加载到 sqlalchemy 中。

Answer 1

明白了。

pip install sqlacodegen

在终端中运行

sqlacodegen mysql://root:pass@localhost/power > models.py