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我正在使用 Postgres sql 数据库。我需要针对database-A我从该查询中获得的任何结果运行 SQL 查询，我需要将结果database-B按原样插入，这必须在每周周五进行。

所以我决定使用ScheduledExecutorServicewhich 将在周五每周调用一个特定的方法来完成上述工作。

以下是我(getFromDatabase)每周五运行的方法 -

在下面的方法中，我正在执行一个简单的选择查询，database-A并将结果存储在TestResponse方法中

protected static void getFromDatabase() {
    TestResponse response = null;
    TestDaoImpl dao = new TestDaoImpl();
    String sql1 = "select col1, col2 from application limit 5";
    try {
        // get the data from database-A table
        response = dao.getFromDatabaseA(sql1);
        System.out.println(response);

        // now iterate this response and then insert into database-B table
        insertIntoDatabase(response);
    } catch (Exception e) {
        e.printStackTrace();
    }
}

private static void insertIntoDatabase(TestResponse resp) {
    // how to use resp so that I can generate below correct insert SQL query?
    // which I can use to execute it?

    String query = "INSERT into table-database-B .... ";
}

以下是我的getFromDatabaseA 方法 -

private List<String> col1List = new LinkedList<String>();
private List<String> col2List = new LinkedList<String>();

 public TestResponse getFromDatabaseA(String query) throws Exception {
    TestResponse response = new TopMalwareAppsResponse();
    try {
        conn = TestConnection.getInstance().getCpds().getConnection();
        statement = conn.createStatement();
        rs = statement.executeQuery(query);
        // Extract data from result set
        while (rs.next()) {
        // Retrieve by column name
        String col1 = rs.getString("col1");
        col1List.add(col1);

        String col2 = rs.getString("col2");
        col2List.add(col2);
       }

        response.setCol1(col1List);
        response.setCol2(col2List);

    } catch (Exception e) {
        e.printStackTrace();
    }
    return response;
    }

下面是我的TestResponse类，其中的所有值都col1将进入col1链表，所有的值都col2将进入col2链表。

public class TestResponse {

    private List<String> col1;
    private List<String> col2;

    // getters and setters
}

现在我不确定如何以这种方式迭代TestResponse方法insertIntoDatabase，以便能够进行正确的 SQL 查询。然后我可以按原样使用这个 SQL 查询来插入。

4

2 回答 2

1

您将列详细信息列表插入到对象中，这不是一个好的行为，

将其更改为

    public class TestResponse {

  private String col1;
  private String col2;

 // getters and setters
  }

使用喜欢

     List<TestResponse> responses = null;

利用

    private static void insertIntoDatabase(List<TestResponse> resps) {
// how to use resp so that I can generate below correct insert SQL query?
// which I can use to execute it?
**// Iterate the above list and update second table**
String query = "INSERT into table-database-B .... ";

}

改变

    getFromDatabaseA

像这样

     List<TestResponse> testResponses = new ArrayList<TestResponse>();

     // Iterate for values or execute query for multiple time to get all details from table 1
   {  
     TestResponse testResponse = new TestResponse();
     testResponse.setsetCol1(/*  ADD COL1 DATA */);
     testResponse.setsetCol2(/*  ADD COL2 DATA */);

     testResponses.add(testResponse);
     }
     return testResponses;
于 2014-03-03T05:40:21.013 回答
-2 
SELECT * FROM old_table INTO new_table

或者你可以使用

 insert into table2 values(select * FROM table1);
于 2014-03-03T04:54:02.747 回答