取得数据库自动生成的主键
@Test
public void testGetKeyValue() {
Connection connection = null;
PreparedStatement preparedStatement = null;
try {
connection = JDBCTools.getConnection();
String sql = "INSERT INTO customers(name, email, birth)" +
"VALUES(?,?,?)";
// preparedStatement = connection.prepareStatement(sql);
//使用重载的 prepareStatement(sql, flag)
//来生成 PreparedStatement 对象
preparedStatement = connection.prepareStatement(sql,
Statement.RETURN_GENERATED_KEYS);
preparedStatement.setString(1, "ABCDE");
preparedStatement.setString(2, "abcde@atguigu.com");
preparedStatement.setDate(3,
new Date(new java.util.Date().getTime()));
preparedStatement.executeUpdate();
//通过 getGeneratedKeys() 获取包含了新生成的主键的 ResultSet 对象
//在 ResultSet 中只有一列 GENERATED_KEY, 用于存放新生成的主键值.
ResultSet rs = preparedStatement.getGeneratedKeys();
if(rs.next()){
System.out.println(rs.getObject(1));
}
ResultSetMetaData rsmd = rs.getMetaData();
for(int i = 0; i < rsmd.getColumnCount(); i++){
System.out.println(rsmd.getColumnName(i + 1));
}
} catch (Exception e) {
e.printStackTrace();
} finally{
JDBCTools.releaseDB(null, preparedStatement, connection);
}
}
