Java 示例 - 保存点和回滚的使用

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  问题描述

  如何在 Java 中创建保存点和回滚？
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  解决方案

  以下示例使用回滚连接方法回滚到以前保存的 SavePoint。

  
  import java.sql.*;
  public class jdbcConn {
     public static void main(String[] args) throws Exception {
        Class.forName("org.apache.derby.jdbc.ClientDriver");
        Connection con = DriverManager.getConnection(
           "jdbc:derby://localhost:1527/testDb","name","pass");
        
        Statement stmt = con.createStatement();
        String query1 = "insert into emp values(5,'name','job')";
        String query2 = "select * from emp";
        
        con.setAutoCommit(false);
        Savepoint spt1 = con.setSavepoint("svpt1");
        stmt.execute(query1);
        ResultSet rs = stmt.executeQuery(query2);
        int no_of_rows = 0;
        
        while (rs.next()) {
           no_of_rows++;
        }
        System.out.println("rows before rollback statement = " + no_of_rows);
        con.rollback(spt1);
        con.commit();
        no_of_rows = 0;
        rs = stmt.executeQuery(query2);
        
        while (rs.next()) {
           no_of_rows++;
        }
        System.out.println("rows after rollback statement = " + no_of_rows);
     }
  }
  

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  结果

  上面的代码示例将产生以下结果。结果可能会有所不同。

  
  rows before rollback statement = 4
  rows after rollback statement = 3