带有Statement.RETURN_GENERATED_KEYS的PreparedStatement

Question

返回的一些JDBC驱动程序的唯一方法Statement.RETURN_GENERATED_KEYS是执行以下操作:

long key = -1L;
Statement statement = connection.createStatement();
statement.executeUpdate(YOUR_SQL_HERE, Statement.RETURN_GENERATED_KEYS);
ResultSet rs = statement.getGeneratedKeys();
if (rs != null && rs.next()) {
    key = rs.getLong(1);
}

有没有办法做同样的事情PreparedStatement？

---

编辑

我问我是否可以这样做的原因PreparedStatement考虑以下情况:

private static final String SQL_CREATE = 
            "INSERT INTO
            USER(FIRST_NAME, MIDDLE_NAME, LAST_NAME, EMAIL_ADDRESS, DOB) 
            VALUES (?, ?, ?, ?, ?)";

在USER表中有一个PRIMARY KEY (USER_ID)是BIGINT AUTOINCREMENT(因此你没有在SQL_CREATE字符串中看到它.

现在,我填充?使用PreparedStatement.setXXXX(index, value).我想回来ResultSet rs = PreparedStatement.getGeneratedKeys().我怎样才能做到这一点？

Answer 1

您可以使用该prepareStatement方法获取其他int参数

PreparedStatement ps = con.prepareStatement(sql, Statement.RETURN_GENERATED_KEYS)

对于某些JDBC驱动程序(例如,Oracle),您必须显式列出生成的键的列名称或索引:

PreparedStatement ps = con.prepareStatement(sql, new String[]{"USER_ID"})

Answer 2

你的意思是这样的？

long key = -1L;

PreparedStatement preparedStatement = connection.prepareStatement(YOUR_SQL_HERE, PreparedStatement.RETURN_GENERATED_KEYS);
preparedStatement.setXXX(index, VALUE);
preparedStatement.executeUpdate();

ResultSet rs = preparedStatement.getGeneratedKeys();

if (rs.next()) {
    key = rs.getLong(1);
}

Answer 3

我现在没有编译器,我会回答一个问题:

你试过这个吗？它有用吗？

long key = -1L;
PreparedStatement statement = connection.prepareStatement();
statement.executeUpdate(YOUR_SQL_HERE, PreparedStatement.RETURN_GENERATED_KEYS);
ResultSet rs = statement.getGeneratedKeys();
if (rs != null && rs.next()) {
    key = rs.getLong(1);
}

免责声明:显然,我没有编译这个,但你明白了.

PreparedStatement是Statement的子接口,所以我没有看到为什么这不起作用的原因,除非一些JDBC驱动程序有问题.

Answer 4

String query = "INSERT INTO ....";
PreparedStatement preparedStatement = connection.prepareStatement(query, PreparedStatement.RETURN_GENERATED_KEYS);

preparedStatement.setXXX(1, VALUE); 
preparedStatement.setXXX(2, VALUE); 
....
preparedStatement.executeUpdate();  

ResultSet rs = preparedStatement.getGeneratedKeys();  
int key = rs.next() ? rs.getInt(1) : 0;

if(key!=0){
    System.out.println("Generated key="+key);
}