Java使用screw来对比数据库表和字段差异
作者:Harries Blog
这篇文章主要介绍了Java如何使用screw来对比数据库表和字段差异,文中的示例代码讲解详细,感兴趣的小伙伴可以跟随小编一起学习一下
1.Screw 库简介
Screw 是一个用于数据库结构分析和文档生成的 Java 库。它支持多种数据库,包括 MySQL、PostgreSQL 和 Oracle。Screw 可以帮助开发者快速获取数据库的表结构、字段信息,并进行比较。
2.原理
使用 Screw 库对比数据库表和字段的基本原理如下:
- 连接数据库:使用 JDBC 连接到需要对比的两个数据库。
- 获取表结构:使用 Screw 提供的 API 获取每个数据库中的表和字段信息。
- 比较表和字段:将两个数据库的表和字段信息进行比较,识别出存在的差异。
- 生成报告:将比较结果生成报告,方便后续查看和分析。
3.环境搭建
第一个mysql数据库
docker run --name docker-mysql -e MYSQL_ROOT_PASSWORD=123456 -p 3306:3306 -d mysql
初始化数据
CREATE DATABASE database1; USE database1; CREATE TABLE users ( id INT AUTO_INCREMENT PRIMARY KEY, username VARCHAR(50) NOT NULL, email VARCHAR(100) NOT NULL UNIQUE, created_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP ); CREATE TABLE orders ( id INT AUTO_INCREMENT PRIMARY KEY, user_id INT NOT NULL, product_name VARCHAR(100) NOT NULL, quantity INT NOT NULL, order_date TIMESTAMP DEFAULT CURRENT_TIMESTAMP, FOREIGN KEY (user_id) REFERENCES users(id) ); CREATE DATABASE database2; USE database2; CREATE TABLE customers ( id INT AUTO_INCREMENT PRIMARY KEY, name VARCHAR(50) NOT NULL, email VARCHAR(100) NOT NULL UNIQUE, registered_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP ); CREATE TABLE purchases ( id INT AUTO_INCREMENT PRIMARY KEY, customer_id INT NOT NULL, item_name VARCHAR(100) NOT NULL, amount INT NOT NULL, purchase_date TIMESTAMP DEFAULT CURRENT_TIMESTAMP, FOREIGN KEY (customer_id) REFERENCES customers(id) ); CREATE TABLE orders ( id INT AUTO_INCREMENT PRIMARY KEY, user_id INT NOT NULL, quantity INT NOT NULL, order_date TIMESTAMP DEFAULT CURRENT_TIMESTAMP );
说明
msyql账号root
mysql密码123456
4.代码工程
目标
使用 Screw 库对比两个 MySQL 数据库表和字段
pom.xml
<?xml version="1.0" encoding="UTF-8"?> <project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd"> <parent> <artifactId>springboot-demo</artifactId> <groupId>com.et</groupId> <version>1.0-SNAPSHOT</version> </parent> <modelVersion>4.0.0</modelVersion> <artifactId>Screw</artifactId> <properties> <maven.compiler.source>8</maven.compiler.source> <maven.compiler.target>8</maven.compiler.target> </properties> <dependencies> <dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-web</artifactId> </dependency> <dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-autoconfigure</artifactId> </dependency> <dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-test</artifactId> <scope>test</scope> </dependency> <dependency> <groupId>cn.smallbun.screw</groupId> <artifactId>screw-core</artifactId> <version>1.0.5</version> </dependency> <dependency> <groupId>org.apache.poi</groupId> <artifactId>poi-ooxml</artifactId> <version>5.2.3</version> </dependency> <dependency> <groupId>org.apache.logging.log4j</groupId> <artifactId>log4j-api</artifactId> <version>2.24.1</version> </dependency> <dependency> <groupId>org.apache.logging.log4j</groupId> <artifactId>log4j-core</artifactId> <version>2.24.1</version> </dependency> <dependency> <groupId>mysql</groupId> <artifactId>mysql-connector-java</artifactId> <scope>runtime</scope> </dependency> <dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-data-jdbc</artifactId> </dependency> </dependencies> </project>
对比代码
package com.et; import cn.smallbun.screw.core.query.DatabaseQuery; import cn.smallbun.screw.core.query.mysql.MySqlDataBaseQuery; import cn.smallbun.screw.core.query.mysql.model.MySqlColumnModel; import cn.smallbun.screw.core.query.mysql.model.MySqlTableModel; import com.zaxxer.hikari.HikariConfig; import com.zaxxer.hikari.HikariDataSource; import org.apache.poi.xwpf.usermodel.*; import javax.sql.DataSource; import java.io.FileOutputStream; import java.util.HashMap; import java.util.List; import java.util.Map; public class DatabaseComparison { public static void main(String[] args) { // Configure database connection information HikariConfig hikariConfig1 = new HikariConfig(); hikariConfig1.setDriverClassName("com.mysql.cj.jdbc.Driver"); hikariConfig1.setJdbcUrl("jdbc:mysql://127.0.0.1:3306/database1"); hikariConfig1.setUsername("root"); hikariConfig1.setPassword("123456"); hikariConfig1.addDataSourceProperty("useInformationSchema", "true"); hikariConfig1.setMinimumIdle(2); hikariConfig1.setMaximumPoolSize(5); DataSource dataSource1 = new HikariDataSource(hikariConfig1); DatabaseQuery query1 = new MySqlDataBaseQuery(dataSource1); HikariConfig hikariConfig2 = new HikariConfig(); hikariConfig2.setDriverClassName("com.mysql.cj.jdbc.Driver"); hikariConfig2.setJdbcUrl("jdbc:mysql://127.0.0.1:3306/database2"); hikariConfig2.setUsername("root"); hikariConfig2.setPassword("123456"); hikariConfig2.addDataSourceProperty("useInformationSchema", "true"); hikariConfig2.setMinimumIdle(2); hikariConfig2.setMaximumPoolSize(5); DataSource dataSource2 = new HikariDataSource(hikariConfig2); DatabaseQuery query2 = new MySqlDataBaseQuery(dataSource2); try { // Retrieve table structure List<MySqlTableModel> tableInfos1 = (List<MySqlTableModel>) query1.getTables(); List<MySqlTableModel> tableInfos2 = (List<MySqlTableModel>) query2.getTables(); // Create Word document XWPFDocument document = new XWPFDocument(); XWPFParagraph titleParagraph = document.createParagraph(); titleParagraph.createRun().setText("Database Table and Field Comparison"); titleParagraph.setAlignment(ParagraphAlignment.CENTER); // Create table for database comparison XWPFTable table = document.createTable(); XWPFTableRow headerRow = table.getRow(0); headerRow.getCell(0).setText("Table Name"); headerRow.addNewTableCell().setText("Exists in Database 1"); headerRow.addNewTableCell().setText("Exists in Database 2"); // Compare tables Map<String, MySqlTableModel> tableMap1 = new HashMap<>(); for (MySqlTableModel tableInfo : tableInfos1) { tableMap1.put(tableInfo.getTableName(), tableInfo); } Map<String, MySqlTableModel> tableMap2 = new HashMap<>(); for (MySqlTableModel tableInfo : tableInfos2) { tableMap2.put(tableInfo.getTableName(), tableInfo); } // Record table differences for (String tableName : tableMap1.keySet()) { XWPFTableRow row = table.createRow(); row.getCell(0).setText(tableName); row.getCell(1).setText("Yes"); row.getCell(2).setText(tableMap2.containsKey(tableName) ? "Yes" : "No"); } for (String tableName : tableMap2.keySet()) { if (!tableMap1.containsKey(tableName)) { XWPFTableRow row = table.createRow(); row.getCell(0).setText(tableName); row.getCell(1).setText("No"); row.getCell(2).setText("Yes"); } } // Add table differences title document.createParagraph().createRun().setText("\nTable Differences:"); for (String tableName : tableMap1.keySet()) { if (!tableMap2.containsKey(tableName)) { document.createParagraph().createRun().setText("Table " + tableName + " does not exist in Database 2"); } else { compareColumns(document, tableMap1.get(tableName), tableMap2.get(tableName), query1, query2); } } for (String tableName : tableMap2.keySet()) { if (!tableMap1.containsKey(tableName)) { document.createParagraph().createRun().setText("Table " + tableName + " does not exist in Database 1"); } } // Save Word document try (FileOutputStream out = new FileOutputStream("D://tmp/Database_Comparison.docx")) { document.write(out); } System.out.println("Database table and field differences have been generated in the Word document."); } catch (Exception e) { e.printStackTrace(); System.out.println("An error occurred: " + e.getMessage()); } } private static void compareColumns(XWPFDocument document, MySqlTableModel mySqlTableModel1, MySqlTableModel mySqlTableModel2, DatabaseQuery query1, DatabaseQuery query2) { // Retrieve column information for both tables List<MySqlColumnModel> columnNames1 = (List<MySqlColumnModel>) query1.getTableColumns(mySqlTableModel1.getTableName()); List<MySqlColumnModel> columnNames2 = (List<MySqlColumnModel>) query2.getTableColumns(mySqlTableModel2.getTableName()); // Create mappings from column names to column models Map<String, MySqlColumnModel> columnsMap1 = new HashMap<>(); for (MySqlColumnModel column : columnNames1) { columnsMap1.put(column.getColumnName(), column); } Map<String, MySqlColumnModel> columnsMap2 = new HashMap<>(); for (MySqlColumnModel column : columnNames2) { columnsMap2.put(column.getColumnName(), column); } // Create column difference table XWPFTable columnTable = document.createTable(); XWPFTableRow columnHeaderRow = columnTable.getRow(0); columnHeaderRow.getCell(0).setText("Column Name"); columnHeaderRow.addNewTableCell().setText("Exists in Database 1"); columnHeaderRow.addNewTableCell().setText("Exists in Database 2"); // Compare columns for (String columnName : columnsMap1.keySet()) { XWPFTableRow row = columnTable.createRow(); row.getCell(0).setText(columnName); row.getCell(1).setText("Yes"); row.getCell(2).setText(columnsMap2.containsKey(columnName) ? "Yes" : "No"); if (!columnsMap2.containsKey(columnName)) { document.createParagraph().createRun().setText("Column " + columnName + " does not exist in table " + mySqlTableModel2.getTableName()); } else { // Compare column types and other properties MySqlColumnModel column1 = columnsMap1.get(columnName); MySqlColumnModel column2 = columnsMap2.get(columnName); // Compare column types if (!column1.getDataType().equals(column2.getDataType())) { document.createParagraph().createRun().setText("Column " + columnName + " in table " + mySqlTableModel1.getTableName() + " has type " + column1.getDataType() + ", while in table " + mySqlTableModel2.getTableName() + " it has type " + column2.getDataType()); } } } // Check reverse differences for (String columnName : columnsMap2.keySet()) { if (!columnsMap1.containsKey(columnName)) { document.createParagraph().createRun().setText("Column " + columnName + " does not exist in table " + mySqlTableModel1.getTableName()); } } } }
代码解析
- 数据库连接配置:使用 HikariCP 配置数据库连接信息,包括数据库 URL、用户名和密码。
- 获取表结构:通过
query.getTables()
方法获取数据库中的表信息。 - 比较表:将两个数据库的表信息存储在
Map
中,并进行比较,输出存在于一个数据库但不存在于另一个数据库的表。 - 比较字段:在比较表的同时,调用
compareColumns
方法获取字段信息,并进行比较,输出字段的存在性和类型差异。
以上只是一些关键代码,所有代码请参见下面代码仓库
代码仓库
https://github.com/Harries/springboot-demo(screw)
5.测试
运行测试类的main方法,将结果写入word文档
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