Java development form data history record and version control function

Java development form data history record and version control function

Introduction:
With the rapid development of the Internet, Java, as a programming language widely used in Web development, plays an important role . In web development, form data carries important information for users to interact with applications. In order to ensure the integrity and traceability of data, developers often need to implement the history recording and version control functions of form data.

1. History Recording Function
The history recording function of form data can record every data modification and its changes, making it convenient for developers to view and restore data.

Implementation method:

1. Database table design
   First, you need to create a history table for the form data. The table needs to contain the following fields:

   • id: unique identifier
   • form_id: id of the form to which it belongs
   • data: JSON format of form data
   • create_time: Creation time

2. Database trigger
   Create a trigger on the main table of form data to automatically add data when the data is inserted or updated. Add to history table. The logic of the trigger is as follows:

   CREATE TRIGGER history_trigger
   AFTER INSERT OR UPDATE ON form_data
   FOR EACH ROW
   BEGIN
       INSERT INTO history_data (form_id, data, create_time) VALUES (NEW.form_id, NEW.data, NOW());
   END;

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Sample code:
Please refer to the following sample code to demonstrate how to create the history recording function of form data.

import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.SQLException;

public class FormDataHistory {
    // 数据库连接信息
    private static final String URL = "jdbc:mysql://localhost:3306/mydb";
    private static final String USER = "root";
    private static final String PASSWORD = "123456";

    // 插入数据的SQL语句
    private static final String INSERT_SQL = "INSERT INTO form_data (form_id, data) VALUES (?, ?)";

    public static void main(String[] args) {
        try (Connection conn = DriverManager.getConnection(URL, USER, PASSWORD);
             PreparedStatement stmt = conn.prepareStatement(INSERT_SQL)) {

            // 假设表单id为1，数据为JSON字符串
            int formId = 1;
            String data = "{"name": "张三", "age": 20}";

            stmt.setInt(1, formId);
            stmt.setString(1, data);

            int rows = stmt.executeUpdate();
            if (rows > 0) {
                System.out.println("数据插入成功");
            } else {
                System.out.println("数据插入失败");
            }
        } catch (SQLException e) {
            e.printStackTrace();
        }
    }
}

The above sample code demonstrates how to insert form data into the database, and the trigger will automatically add the data to the history table. Developers can customize query historical data and perform analysis and operations as needed.

2. Version control function
The version control function can help developers back up and roll back form data to ensure the consistency and correctness of the data.

Implementation method:

1. Version field design
   First, add a version field to the main table of the form data. When the data is updated, this field will automatically increase by 1, indicating the version number of the current data.

   Sample code:

   ALTER TABLE form_data ADD COLUMN version INT NOT NULL DEFAULT 1;

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2. Data backup
   Create a trigger on the main table of the form data to automatically save the current version of the data when the data is updated Back up to history table.

   Sample code:

   CREATE TRIGGER backup_trigger
   AFTER UPDATE ON form_data
   FOR EACH ROW
   BEGIN
       IF NEW.version > OLD.version THEN
           INSERT INTO history_data (form_id, data, create_time) VALUES (NEW.form_id, NEW.data, NOW());
       END IF;
   END;

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3. Data rollback
   Developers can select a specific version of data by querying the history table and restore it to in the main table. The sample code is as follows:

   private static final String SELECT_SQL = "SELECT data FROM history_data WHERE form_id = ? AND version = ?";
   private static final String UPDATE_SQL = "UPDATE form_data SET data = ? WHERE form_id = ?";
   
   try (Connection conn = DriverManager.getConnection(URL, USER, PASSWORD);
        PreparedStatement selectStmt = conn.prepareStatement(SELECT_SQL);
        PreparedStatement updateStmt = conn.prepareStatement(UPDATE_SQL)) {
   
       int formId = 1;
       int version = 2;
   
       selectStmt.setInt(1, formId);
       selectStmt.setInt(2, version);
       ResultSet rs = selectStmt.executeQuery();
   
       if (rs.next()) {
           String data = rs.getString("data");
   
           updateStmt.setString(1, data);
           updateStmt.setInt(2, formId);
   
           int rows = updateStmt.executeUpdate();
           if (rows > 0) {
               System.out.println("数据回滚成功");
           } else {
               System.out.println("数据回滚失败");
           }
       } else {
           System.out.println("找不到指定版本的数据");
       }
   } catch (SQLException e) {
       e.printStackTrace();
   }

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The above sample code demonstrates how to restore a specific version of data in the history table to the main table. Developers can customize query historical data and perform data rollback operations as needed.

Conclusion:
By implementing the historical recording and version control functions of form data, developers can better track and manage data changes and ensure data integrity and traceability. This is crucial for data management and maintenance of web applications, and provides users with better user experience and service quality.

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