Question

我在数据库中成功插入了一条记录，但在显示插入的数据时，一列将始终返回null。

这来自我的数据库助手

private static final String CREATE_TABLE_RECORD = "CREATE TABLE "
        + TABLE_RECORD + "(" + RECORD_ID + " INTEGER PRIMARY KEY," + SUBJECT_ID2
        + " INTEGER," + STUDENT_ID2 +" INTEGER," + TYPE_EXAM + " TEXT," + SCORE + " INTEGER,"+ TOTAL_SCORE + " INTEGER," + CREATED_TIME
        + " DATETIME" + ")";

public long insertRecord(Record s) {
    SQLiteDatabase db = this.getWritableDatabase();

    ContentValues values = new ContentValues();
    values.put(SUBJECT_ID2,s.getSubjectId());
    values.put(STUDENT_ID2,s.getStudentId());
    values.put(SCORE,s.getScore());
    values.put(TYPE_EXAM,s.getTypeOfExam());
    values.put(TOTAL_SCORE,s.getTotalScore());
    values.put(CREATED_TIME,s.getCreatedTime());


    // insert row
    long id = db.insert(TABLE_RECORD, null, values);
    Log.d("Score" ,String.valueOf(values));
    return id;
}

this from my activity

public void saveRecord(View view){
    Intent intent = new Intent(RecordScoreActivity.this, RecordActivity.class);     



    DatabaseHelper db = new DatabaseHelper(getApplicationContext());
    Record sub = new Record(idStudent,idSubject, Integer.parseInt(scoreField.getText().toString()), totalScores,tv1.getText().toString(), createTime );
    Bundle extras = new Bundle();
    extras.putInt("id", idSubject);
    extras.putString("type", typeOfExam);
    extras.putInt("score", totalScores);
    extras.putString("time", createTime);
    intent.putExtras(extras);
    long id = db.insertRecord(sub);
    //int studentId, int subjectId, int recordId, int score,int totalScore, String type,String time

    Log.d("Success","recordId = " + id);
    db.close();

    startActivity(intent);
}

这来自我的logcat

03-03 18:21:17.763: D/Score(2273): score=50 student_id2=1 created_time=2014-3-3 type_exam=null subject_id2=1 total_score=50
03-03 18:21:17.763: D/Success(2273): recordId = 12

我真的不知道为什么我为该列获取空值。

我的记录课

public class Record {

int studentId;
int subjectId;
int recordId;
int totalScore;
int score;
String typeOfExam;
String createdTime;



public Record(){

}

public Record(int studentId, int subjectId, int score,int totalScore, String type,String time){
    this.studentId =studentId;
    this.subjectId = subjectId;
    //this.recordId= recordId;
    this.score = score;
    this.totalScore = totalScore;
    this.createdTime = time;
}

public Record(String time){
    this.createdTime = time;
}

public int getScore() {
    return score;
}

public void setScore(int score) {
    this.score = score;
}

public int getStudentId() {
    return studentId;
}
public void setStudentId(int studentId) {
    this.studentId = studentId;
}
public int getSubjectId() {
    return subjectId;
}
public void setSubjectId(int subjectId) {
    this.subjectId = subjectId;
}
public int getRecordId() {
    return recordId;
}
public void setRecordId(int recordId) {
    this.recordId = recordId;
}
public int getTotalScore() {
    return totalScore;
}
public void setTotalScore(int totalScore) {
    this.totalScore = totalScore;
}
public String getTypeOfExam() {
    return typeOfExam;
}
public void setTypeOfExam(String typeOfExam) {
    this.typeOfExam = typeOfExam;
}
public String getCreatedTime() {
    return createdTime;
}
public void setCreatedTime(String createdTime) {
    this.createdTime = createdTime;
}


}

Answer 1

您忘记将typeOfExam初始化为Record(int studentId, int subject....)构造函数，如下所示：

public Record(int studentId, int subjectId, int score,int totalScore, String type,String time){
this.studentId =studentId;
this.subjectId = subjectId;
this.typeOfExam = type;
this.score = score;
this.totalScore = totalScore;
this.createdTime = time;
}

这就是为什么每次NULL获得typeOfExam值

的原因

Answer 2

Record sub = new Record(idStudent,idSubject, Integer.parseInt(scoreField.getText().toString()), totalScores,tv1.getText().toString(), createTime );

不包含typeOfExam参数，因此该值保持为空。

像这样添加..

Record sub = new Record(idStudent,idSubject, Integer.parseInt(scoreField.getText().toString()), totalScores,tv1.getText().toString(), createTime );
sub.setTypeOfExam(typeOfExam);//this line...

<强>更新

你错过了记录构造函数中的this.typeOfExam = type;

始终在sqlite表中返回null值

2 个答案: