使用screw来对比数据库表和字段差异
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
- 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™