com.example.dilshadazmat.generalknowledge, PID: 8203
java.lang.RuntimeException: Unable to start activity ComponentInfo
{com.example.dilshadazmat.
generalknowledge
/com.example.dilshadazmat.generalknowledge.Islamic_mcqs}:
java.lang.IllegalStateException: getDatabase called recursively
at android.app.ActivityThread.performLaunchActivity
(ActivityThread.java:2689)
at android.app.ActivityThread.handleLaunchActivity
(ActivityThread.java:2756)
at android.app.ActivityThread.access$900(ActivityThread.java:177)
at android.app.ActivityThread$H.handleMessage
(ActivityThread.java:1448)
at android.os.Handler.dispatchMessage(Handler.java:102)
at android.os.Looper.loop(Looper.java:145)
at android.app.ActivityThread.main(ActivityThread.java:5940)
at java.lang.reflect.Method.invoke(Native Method)
at java.lang.reflect.Method.invoke(Method.java:372)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run
(ZygoteInit.java:1389)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1184)
Caused by: java.lang.IllegalStateException: getDatabase
called recursively android.database.sqlite.SQLiteOpenHelper.
getDatabaseLocked(SQLiteOpenHelper.java:203)
at android.database.sqlite.SQLiteOpenHelper.getWritableDatabase
(SQLiteOpenHelper.java:163)
at com.example.dilshadazmat.generalknowledge.DbIslamic.
addQuestions(DbIslamic.java:81)
at com.example.dilshadazmat.generalknowledge.DbIslamic.
addQuestions(DbIslamic.java:59)
at com.example.dilshadazmat.generalknowledge.
DbIslamic.onCreate(DbIslamic.java:49)
at android.database.sqlite.SQLiteOpenHelper.
getDatabaseLocked(SQLiteOpenHelper.java:251)
at android.database.sqlite.SQLiteOpenHelper.
getReadableDatabase(SQLiteOpenHelper.java:187)
at com.example.dilshadazmat.generalknowledge.
DbIslamic.getAllQuestions
(DbIslamic.java:97)
at com.example.dilshadazmat.generalknowledge.Islamic_mcqs.onCreate
slamic_mcqs.java:47)
at android.app.Activity.performCreate(Activity.java:6283)
at android.app.Instrumentation.callActivityOnCreate
(Instrumentation.java:1119)
at android.app.ActivityThread.performLaunchActivity
(ActivityThread.java:26 at
androi
这是我想要创建新数据库的数据库类。这里有我无法理解的问题是什么错误列表让所有人感到无聊。
public class DbIslamic extends SQLiteOpenHelper {
private static final int DATABASE_VERSION = 1;
private static final String DATABASE_NAME = "islamicMcqs";
private static final String TABLE_QUESTION = "questions";
private static final String KEY_ID = "id";
private static final String KEY_QUESTION = "question";
private static final String KEY_ANSWER = "answer";
private static final String KEY_OPTA = "opta";
private static final String KEY_OPTB = "optb";
private static final String KEY_OPTC = "optc";
private static final String KEY_OPTD = "optd";
private SQLiteDatabase database;
public DbIslamic(Context context)
{
super(context, DATABASE_NAME, null, DATABASE_VERSION);
}
@Override
public void onCreate(SQLiteDatabase db)
{
database = db;
String sql = "CREATE TABLE IF NOT EXISTS " + TABLE_QUESTION +
"(" +KEY_ID +
"INTEGER, "
+ KEY_QUESTION + "TEXT," + KEY_OPTA + "TEXT," +
KEY_OPTB + "TEXT," +
KEY_OPTC + "TEXT,"
+ KEY_OPTD + "TEXT,"+ KEY_ANSWER + "TEXT)" ;
db.execSQL (sql);
addQuestions();
db.close();
}
private void addQuestions()
{
Islamic_mcqs q1 = new Islamic_mcqs("Who was the
last prophet in"+" the list of prophets ?", "Hazrat Adam(A.S)",
"Hazrat Muhammad(S.A.W)","Hazrat Yousaf(A.S)",
"Hazrat Ibraheem (A.S)","B");
this.addQuestions(q1);
}
@Override
public void onUpgrade(SQLiteDatabase db, int oldValue, int newValue)
{
// Drop older table if existed
db.execSQL("DROP TABLE IF EXISTS " +TABLE_QUESTION);
// Create tables again
onCreate(db);
}
// Adding new question
public void addQuestions(Islamic_mcqs questions)
{
SQLiteDatabase db = this.getWritableDatabase();
ContentValues values = new ContentValues();
values.put(KEY_QUESTION,questions.getQUESTION());
values.put(KEY_ANSWER,questions.getANSER());
values.put(KEY_OPTA,questions.getOPTA());
values.put(KEY_OPTB,questions.getOPTB());
values.put(KEY_OPTC,questions.getOPTC());
values.put(KEY_OPTD,questions.getOPTD());
// Inserting Row
database.insert(TABLE_QUESTION,null,values);
}
public List<Islamic_mcqs> getAllQuestions()
{
List<Islamic_mcqs> questionsList = new ArrayList<Islamic_mcqs>();
// Select All Query
String selectQuery = "SELECT * FROM " + TABLE_QUESTION;
database=this.getReadableDatabase();
Cursor cursor = database.rawQuery(selectQuery, null);
// looping through all rows and adding to list
if (cursor.moveToFirst()) {
do {
Islamic_mcqs q = new Islamic_mcqs();
q.setID(cursor.getInt(0));
q.setQUESTION(cursor.getString(1));
q.setANSWER(cursor.getString(2));
q.setOPTA(cursor.getString(3));
q.setOPTAB(cursor.getString(4));
q.setOPTC(cursor.getString(5));
q.setOPTD(cursor.getString(6));
questionsList.add(q);
} while (cursor.moveToNext());
}
// return quest list
return questionsList;
}
本课程中的另一个类Islamic_mcqs我想从这个数据库中获取数据库中的所有数据，我将保存多项选择题。
public class Islamic_mcqs extends AppCompatActivity{
private int ID;
private String QUESTION;
private String OPTA;
private String OPTB;
private String OPTC;
private String OPTD;
private String ANSWER;
List<Islamic_mcqs> questionList;
int score = 0;
int qid = 0;
TextView tv_t,tv_num,tv_q;
RadioButton rb_a,rb_b,rb_c,rb_d;
Button bnext;
Islamic_mcqs currentQ;
@Override
protected void onCreate(@Nullable Bundle savedInstanceState)
{
super.onCreate(savedInstanceState);
setContentView(R.layout.islamic_mcqs);
DbIslamic database = new DbIslamic(this);
questionList = database.getAllQuestions();
Islamic_mcqs currentQ = questionList.get(qid);
tv_t = (TextView)findViewById(R.id.tv_title);
tv_q = (TextView)findViewById(R.id.tv_question);
tv_num = (TextView)findViewById(R.id.tvNumber);
rb_a = (RadioButton)findViewById(R.id.rb_A);
rb_b = (RadioButton)findViewById(R.id.rb_B);
rb_c = (RadioButton)findViewById(R.id.rb_C);
rb_d = (RadioButton)findViewById(R.id.rb_D);
bnext = (Button)findViewById(R.id.b_next);
setQuestionView();
}
private void setQuestionView()
{
tv_q.setText(currentQ.getQUESTION());
rb_a.setText(currentQ.getOPTA());
rb_b.setText(currentQ.getOPTB());
rb_c.setText(currentQ.getOPTC());
rb_d.setText(currentQ.getOPTD());
qid++;
}
public Islamic_mcqs()
{
ID = 0;
QUESTION = "";
OPTA = "";
OPTB = "";
OPTC = "";
OPTD = "";
ANSWER = "";
}
public Islamic_mcqs(String islQuestion, String optA,
String optB, String optC, String optD, String answer)
{
QUESTION = islQuestion;
OPTA = optA;
OPTB = optB;
OPTC = optC;
OPTD = optD;
ANSWER = answer;
}
public int getID()
{
return ID;
}
public String getQUESTION()
{
return QUESTION;
}
public String getOPTA()
{
return OPTA;
}
public String getOPTB()
{
return OPTB;
}
public String getOPTC()
{
return OPTC;
}
public String getOPTD()
{
return OPTD;
}
public String getANSER()
{
return ANSWER;
}
public void setID(int id)
{
ID = id;
}
public void setQUESTION(String islQuestion)
{
QUESTION = islQuestion;
}
public void setOPTA(String optA)
{
OPTA = optA;
}
public void setOPTAB(String optab)
{
OPTB = optab;
}
public void setOPTC(String optc)
{
OPTC = optc;
}
public void setOPTD(String optd)
{
OPTD = optd;
}
public void setANSWER(String answer)
{
ANSWER = answer;
}
}
答案 0 :(得分：0)
替换你的Sql。
String sql = "CREATE TABLE IF NOT EXISTS " + TABLE_QUESTION +
"(" +KEY_ID +
" INTEGER, "
+ KEY_QUESTION + " TEXT," + KEY_OPTA + " TEXT," +
KEY_OPTB + " TEXT," +
KEY_OPTC + " TEXT,"
+ KEY_OPTD + " TEXT,"+ KEY_ANSWER + " TEXT);" ;
有空格：KEY_OPTC +“TEXT，”='optc TEXT，'
答案 1 :(得分：0)
INTEGER PRIMARY KEY AUTOINCREMENT， 检查SQLite语句
String sql = "CREATE TABLE IF NOT EXISTS " + TABLE_QUESTION +
"(" +KEY_ID +
"INTEGER, "
+ KEY_QUESTION + "TEXT," + KEY_OPTA + "TEXT," +
KEY_OPTB + "TEXT," +
KEY_OPTC + "TEXT,"
+ KEY_OPTD + "TEXT,"+ KEY_ANSWER + "TEXT)" ;
将其替换为
String sql = "CREATE TABLE IF NOT EXISTS " + TABLE_QUESTION +
"(" +KEY_ID +
"INTEGER PRIMARY KEY AUTOINCREMENT, "
+ KEY_QUESTION + " TEXT," + KEY_OPTA + " TEXT," +
KEY_OPTB + " TEXT," +
KEY_OPTC + " TEXT,"
+ KEY_OPTD + " TEXT,"+ KEY_ANSWER + " TEXT)" ;