Question

我已实现此代码但不起作用。任何人都可以告诉我错误的原因我无法找到它:(这是代码：

PreparedStatement stmA = connsqlite.prepareStatement("SELECT * FROM  dbTable");
PreparedStatement stmB = connphpmyadmin.prepareStatement("INSERT INTO codes VALUES ('"??????????"')");
stmA.executeQuery("DROP TABLE dbTable");
stmB.executeUpdate();

connsqlite.close();
connphpmyadmin.close();

如您所见，我希望同步2个不同的数据库，一个本地服务器和一个服务器。同步完成后，我想从本地数据库中删除表。我认为答案是在＆＃34; ??????＆＃34;我已经提出但我不知道该写些什么。如果有人知道请帮助我理解。谢谢！

Answer 1

这只是一个如何做到这一点的例子。记住?标记是要传递的一个参数/值。因此，您需要根据自己的目的修改查询。我不知道你的表有什么类型的列，所以如果你需要修改它。

        //Representation of single item in table
        class DbTableItem {
            private String value1;
            private String value2;
            private String value3;
            //... Whatever field that required to exchange information between 2 tables
            public String getValue1() {
                return value1;
            }

            public void setValue1(String value1) {
                this.value1 = value1;
            }

            public String getValue2() {
                return value2;
            }

            public void setValue2(String value2) {
                this.value2 = value2;
            }

            public String getValue3() {
                return value3;
            }

            public void setValue3(String value3) {
                this.value3 = value3;
            }
        }

        Connection connection1 =//your connection to local db;
        Connection connection2 =//your connection to another db;
        PreparedStatement stmA = connection.prepareStatement("SELECT * FROM  dbTable");
        //Executing query to retreive data
        ResultSet resultSet = stmA.executeQuery();

        List<DbTableItem> dbTableList = new ArrayList<>();

        //Setting items and adding to list
        while (resultSet.next()){
            DbTableItem dbTableItem = new DbTableItem();
            dbTableItem.setValue1(resultSet.getString("COLUMN_NAME"));
            dbTableItem.setValue2(resultSet.getString("COLUMN_NAME"));
            dbTableItem.setValue2(resultSet.getString("COLUMN_NAME"));
            dbTableList.add(dbTableItem);
        }
        //Preparing next query for batch process
        PreparedStatement stmB = connection2.prepareStatement("INSERT INTO codes VALUES (?,?,?)");
        //Adding to batch
        for(DbTableItem dbTableItem: dbTableList) {
            stmB.setObject(1, dbTableItem.getValue1());
            stmB.setObject(2, dbTableItem.getValue2());
            stmB.setObject(2, dbTableItem.getValue3());
            //And so on
            stmB.addBatch();
        }
        //Executing batch with query
        stmB.executeBatch();

        //Droping table
        //Closing connection1 and connection2

如何将表值从数据库复制到另一个数据库

1 个答案: