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 informationHikariConfig 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 structureList<MySqlTableModel> tableInfos1 = (List<MySqlTableModel>) query1.getTables();List<MySqlTableModel> tableInfos2 = (List<MySqlTableModel>) query2.getTables();// Create Word documentXWPFDocument document = new XWPFDocument();XWPFParagraph titleParagraph = document.createParagraph();titleParagraph.createRun().setText("Database Table and Field Comparison");titleParagraph.setAlignment(ParagraphAlignment.CENTER);// Create table for database comparisonXWPFTable 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 tablesMap<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 differencesfor (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 titledocument.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 documenttry (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 tablesList<MySqlColumnModel> columnNames1 = (List<MySqlColumnModel>) query1.getTableColumns(mySqlTableModel1.getTableName());List<MySqlColumnModel> columnNames2 = (List<MySqlColumnModel>) query2.getTableColumns(mySqlTableModel2.getTableName());// Create mappings from column names to column modelsMap<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 tableXWPFTable 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 columnsfor (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 propertiesMySqlColumnModel column1 = columnsMap1.get(columnName);MySqlColumnModel column2 = columnsMap2.get(columnName);// Compare column typesif (!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 differencesfor (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
- GitHub - Harries/springboot-demo: a simple springboot demo with some components for example: redis,solr,rockmq and so on.(screw)
5.测试
运行测试类的main方法,将结果写入word文档
6.引用
- 使用screw来对比数据库表和字段差异 | Harries Blog™