java.sql.SQLException : Could not set parameter at position 1 (values was 1) using jdbc. queryForObject

Question

无法确定导致此异常的主要原因在哪里。我按照 Spring in Action 的书做了一切。这几行代码有什么问题？

private static final String PREFIX_SELECT_SQL = "SELECT ID, " +
        "CATEGORY_ID, " +
        "STATE_ID, " +
        "TASK_DESCRIPTION, " +
        "CREATION_TASK_DATE, " +
        "START_TASK_DATE, " +
        "END_TASK_DATE, " +
        "USER_ID FROM tasks ";

public Task findOneTask(int taskId) {
    Task task = jdbc.queryForObject(PREFIX_SELECT_SQL
            + "WHERE ID = " + taskId + ";", this::mapRowToTaskTable, taskId);
    return task;
}

private Task mapRowToTaskTable(ResultSet resultSet, int i) throws SQLException {
    Task task = new Task();

    task.setTaskId(resultSet.getInt("ID"));
    task.setUserId(resultSet.getInt("USER_ID"));
    task.setDescription(resultSet.getString("TASK_DESCRIPTION"));
    task.setCategoryId(resultSet.getInt("CATEGORY_ID"));
    task.setStateId(resultSet.getInt("STATE_ID"));
    task.setStartDate(resultSet.getTimestamp("START_TASK_DATE").toLocalDateTime());
    if (resultSet.getTimestamp("END_TASK_DATE") != null) {
        task.setEndDate(resultSet.getTimestamp("END_TASK_DATE").toLocalDateTime());
    } else {
        task.setEndDate(null);
    }
    task.setCreateDate(resultSet.getTimestamp("CREATION_TASK_DATE").toLocalDateTime());

    return task;
}

Answer 1

您已经向 jdbc.queryForObject 查询传递了具体值，但不是参数。

Select ...
from ...
where id = 123

将 findOneTask 更改为:

public Task findOneTask(int taskId) {
  Task task = jdbc.queryForObject(PREFIX_SELECT_SQL
            + "WHERE ID = ?;", this::mapRowToTaskTable, taskId);
  return task;
}