The query data returned by the print database is null or the default value. Does not match the value returned by the database

Test environment IDEA2021

When printing the class average , I found that the average score of all classes is 0.0

I checked it first SQL sentence , Make sure there are no errors  

public List<ClassAvgScore> queryClassAvgScore(){
   return scoreDAO.QueryMany("SELECT ClassRoom,AVG(score) AS score FROM Student  GROUP BY  ClassRoom  ORDER BY ClassRoom ASC,AVG(score)DESC;",ClassAvgScore.class);
}

Database student table

  It took a long time to find the mapping class attribute name used to receive the query results ( I don't know what to call it ) Write the wrong . It is not the same as the column name of the database table

private int ClassRoom;
private double AvgScore;

public double getAvgScore() {
    return AvgScore;
}

public void setAvgScore(double avgScore) {
    AvgScore = avgScore;
}

public int getClassRoom() {
    return ClassRoom;
}

  What is written in the mapping class is AvgScore The column name of the database table is score Data cannot be loaded .

terms of settlement

Change the attribute name in the mapping class to be the same as the column name of the database table

Be careful ： My search statement renames the column name as score , Therefore, the attribute name of the mapping class should be changed to the renamed name instead of the column name of the table （ Although the column name of my renamed table is the same as that of the original table , Ha ha ha ）. Just pay attention