java.sq.SQLException：未找到列
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java.sq.SQLException: Column not found
提问by Matthew Moisen
I am receiving the following error:
我收到以下错误：
HTTP Status 500 - Request processing failed; nested exception is
org.springframework.jdbc.BadSqlGrammarException: StatementCallback; bad SQL grammar
[SELECT id, name FROM track WHERE category_id = 1 ORDER BY name]; nested exception is
java.sql.SQLException: Column 'category_id' not found.
But when I copy and paste the very select statement listed in the error into a mysql shell, I get the result, which is expected as the table trackhas the column category_id.
但是，当我将错误中列出的 select 语句复制并粘贴到 mysql shell 中时，我得到了结果，这是预期的，因为该表track具有category_id.
What could be a reason for this error?
此错误的原因可能是什么？
Here is the table create statement for track:
这是表的创建语句track：
CREATE TABLE track (
id SERIAL
,name VARCHAR(50)
,category_id BIGINT UNSIGNED -- This references a serial (bigint unsigned)
,CONSTRAINT track_id_pk PRIMARY KEY (id)
,CONSTRAINT track_category_id_fk FOREIGN KEY
(category_id) REFERENCES category (id)
);
Here are some lines from my dao class regarding the tracktable:
以下是我的 dao 类中关于track表的一些行：
private static final class TrackMapper implements RowMapper<Track> {
@Override
public Track mapRow(ResultSet resultSet, int rowNum) throws SQLException {
Track track = new Track();
track.setId(resultSet.getInt("id"));
track.setName(resultSet.getString("name"));
track.setCategoryId(resultSet.getInt("category_id"));
return track;
}
}
public List<Track> getTracks(int categoryId) {
String sql = "SELECT id, name FROM track WHERE category_id = " + categoryId + " ORDER BY name";
return jdbcTemplate.query(sql, new TrackMapper());
}
采纳答案by kevinpeterson
Check your SQL statement -- you need to include the category_idin the column list:
检查您的 SQL 语句——您需要将 包含category_id在列列表中：
String sql = "SELECT id, name, category_id FROM track WHERE category_id = " + categoryId + " ORDER BY name";
String sql = "SELECT id, name, category_id FROM track WHERE category_id = " + categoryId + " ORDER BY name";
It is failing because you're trying to extract category_idfrom the ResultSetand it isn't there.
这是失败的，因为你想提取category_id从ResultSet与它不存在。
