java - Android - SQLiteDatabase 没有这样的表错误(代码 1)

标签 java android sqlite android-sqlite sqliteopenhelper

我的应用程序中有一个 ListView，用户可以向其中添加/删除 项目。我正在使用 SQLiteDatabase 在未使用应用程序时存储项目，但是 SQLiteDatabase 给我一个奇怪的错误，说 “找不到这样的表:subjects(代码 1)。我不明白为什么会这样，我之前使用过几次 SQLiteDatabase，但这次它就是不工作。

这是我的代码:

SubjectsDatabase.java - 

import java.util.ArrayList;

import android.content.ContentValues;
import android.content.Context;
import android.database.Cursor;
import android.database.SQLException;
import android.database.sqlite.SQLiteDatabase;
import android.database.sqlite.SQLiteOpenHelper;

public class SubjectsDatabase extends SQLiteOpenHelper {

private static final String SUBJECT_ID = "id";
private static final String SUBJECT_NAME = "name";

private static final String DATABASE_NAME = "subjectsDatabase";
private static final String TABLE_SUBJECTS = "subjects";
private static final int DATABASE_VERSION = 1;

private static final String DATABASE_CREATE = "CREATE_TABLE" + TABLE_SUBJECTS + "(" + 
                        SUBJECT_ID + "INTEGER_PRIMARY_KEY, " + SUBJECT_NAME + "TEXT" + ")";
public SubjectsDatabase(Context context) {
    super(context, DATABASE_NAME, null, DATABASE_VERSION);
}
@Override
public void onCreate(SQLiteDatabase db) {
    try {
        db.execSQL(DATABASE_CREATE);
    }
    catch(SQLException e) {
        e.printStackTrace();
    }
}
@Override
public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {

    db.execSQL("DROP TABLE IF EXSISTS topics");
    onCreate(db);
}
public void addSubject(Subject subject) {
    SQLiteDatabase db = this.getWritableDatabase();

    ContentValues topics = new ContentValues();
    topics.put(SUBJECT_NAME, subject.getSubject());

    db.insert(TABLE_SUBJECTS, null, topics);
    db.close();
}
public void removeSubject(Subject subject) {

    SQLiteDatabase db = this.getWritableDatabase();

    db.delete(TABLE_SUBJECTS, SUBJECT_NAME + " = ?", 
            new String[] {String.valueOf(subject.getSubject())});

    db.close();
}
public ArrayList<Subject> getSubjects(){

    ArrayList<Subject> topics = new ArrayList<Subject>();

    String selectQuery = "SELECT * FROM " + TABLE_SUBJECTS;

    SQLiteDatabase db = this.getWritableDatabase();
    Cursor cur = db.rawQuery(selectQuery, null);

    if(cur.moveToFirst()) {
        do {
            Subject subject = new Subject();
            subject.setId(Integer.parseInt(cur.getString(0)));
            subject.setSubject(cur.getString(1));
            topics.add(subject);
        } while(cur.moveToNext());
    }
    db.close();
    return topics;
}
public void updateSubject(Subject old_name, Subject new_name) {
    SQLiteDatabase db = this.getWritableDatabase();

    ContentValues topic = new ContentValues();

    topic.put(SUBJECT_NAME, new_name.getSubject());

    db.update(TABLE_SUBJECTS, topic, SUBJECT_NAME + " = ?", 
            new String[] {String.valueOf(old_name.getSubject())});
    db.close();
}
}

主题.java - 

public class Subject {

String _subject;
int _id;
public Subject() {

}
public Subject(String subject) {
    this._subject = subject;
}
public String getSubject() {
    return _subject;
}
public void setSubject(String subject) {
    this._subject = subject;
}
public int getId() {
    return _id;
}
public void setId(int id) {
    this._id = id;
}
}

Add_Notes.java - 

import java.util.ArrayList;

import android.os.Bundle;
import android.app.Activity;
import android.app.AlertDialog;
import android.app.AlertDialog.Builder;
import android.app.Dialog;
import android.content.Context;
import android.content.DialogInterface;
import android.view.Menu;
import android.view.View;
import android.view.inputmethod.InputMethodManager;
import android.widget.EditText;
import android.widget.ListView;


public class Add_Notes extends Activity {

private ItemAdapter adapter;
private ArrayList<Subject> menu_items;
private SubjectsDatabase db = new SubjectsDatabase(this);
private ListView subjects;
private InputMethodManager imm;

@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_add__notes);

    menu_items = db.getSubjects();
    adapter = new ItemAdapter(this, menu_items);
    subjects = (ListView) findViewById(R.id.subjects);

    subjects.setAdapter(adapter);
}

public void onClickAddSubjects(View v) {
    showDialog(0);
    showKeyboard();
}

protected Dialog onCreateDialog(int id) {
    switch(id) {
    case 0:
        Builder builder = new AlertDialog.Builder(this);
        final EditText SubjectName = new EditText(this);
        SubjectName.setHint("Subject Name");
        builder.setView(SubjectName);
        builder.setPositiveButton("OK", new DialogInterface.OnClickListener() {

            public void onClick(DialogInterface arg0, int arg1) {

                String subjectName = SubjectName.getText().toString();

                db.addSubject(new Subject(subjectName));

                adapter.add(new Subject(subjectName));
                adapter.notifyDataSetChanged();

                SubjectName.setText("");
                dismissDialog(0);
                removeDialog(0);
                hideKeyboard();
            }
        });
        builder.setNegativeButton("Cancel", new DialogInterface.OnClickListener() {

            public void onClick(DialogInterface arg0, int arg1) {

                SubjectName.setText("");
                dismissDialog(0);
                removeDialog(0);
                hideKeyboard();

            }
        });
        return builder.create();
    }
    return null;
}

public void showKeyboard() {
    imm = (InputMethodManager) getSystemService(Context.INPUT_METHOD_SERVICE);
    imm.toggleSoftInput(InputMethodManager.SHOW_FORCED, 0);
}

public void hideKeyboard() {
    imm.toggleSoftInput(InputMethodManager.RESULT_HIDDEN, 0);
}

@Override
public boolean onCreateOptionsMenu(Menu menu) {
    getMenuInflater().inflate(R.menu.activity_add__notes, menu);
    return true;
}
}

这是错误日志 - 

04-09 18:08:42.133: E/linker(31508): load_library(linker.cpp:759): library "libmaliinstr.so" not found
04-09 18:08:42.965: E/SQLiteLog(31508): (1) no such table: subjects
04-09 18:08:42.984: E/AndroidRuntime(31508): FATAL EXCEPTION: main
04-09 18:08:42.984: E/AndroidRuntime(31508): java.lang.RuntimeException: Unable to start activity ComponentInfo{com.Swap.RR/com.Swap.RR.Add_Notes}: android.database.sqlite.SQLiteException: no such table: subjects (code 1): , while compiling: SELECT * FROM subjects
04-09 18:08:42.984: E/AndroidRuntime(31508):    at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2364)
04-09 18:08:42.984: E/AndroidRuntime(31508):    at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2416)
04-09 18:08:42.984: E/AndroidRuntime(31508):    at android.app.ActivityThread.access$600(ActivityThread.java:174)
04-09 18:08:42.984: E/AndroidRuntime(31508):    at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1382)
04-09 18:08:42.984: E/AndroidRuntime(31508):    at android.os.Handler.dispatchMessage(Handler.java:107)
04-09 18:08:42.984: E/AndroidRuntime(31508):    at android.os.Looper.loop(Looper.java:194)
04-09 18:08:42.984: E/AndroidRuntime(31508):    at android.app.ActivityThread.main(ActivityThread.java:5409)
04-09 18:08:42.984: E/AndroidRuntime(31508):    at java.lang.reflect.Method.invokeNative(Native Method)
04-09 18:08:42.984: E/AndroidRuntime(31508):    at java.lang.reflect.Method.invoke(Method.java:525)
04-09 18:08:42.984: E/AndroidRuntime(31508):    at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:839)
04-09 18:08:42.984: E/AndroidRuntime(31508):    at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:606)
04-09 18:08:42.984: E/AndroidRuntime(31508):    at dalvik.system.NativeStart.main(Native Method)
04-09 18:08:42.984: E/AndroidRuntime(31508): Caused by: android.database.sqlite.SQLiteException: no such table: subjects (code 1): , while compiling: SELECT * FROM subjects
04-09 18:08:42.984: E/AndroidRuntime(31508):    at android.database.sqlite.SQLiteConnection.nativePrepareStatement(Native Method)
04-09 18:08:42.984: E/AndroidRuntime(31508):    at android.database.sqlite.SQLiteConnection.acquirePreparedStatement(SQLiteConnection.java:886)
04-09 18:08:42.984: E/AndroidRuntime(31508):    at android.database.sqlite.SQLiteConnection.prepare(SQLiteConnection.java:497)
04-09 18:08:42.984: E/AndroidRuntime(31508):    at android.database.sqlite.SQLiteSession.prepare(SQLiteSession.java:588)
04-09 18:08:42.984: E/AndroidRuntime(31508):    at android.database.sqlite.SQLiteProgram.<init>(SQLiteProgram.java:58)
04-09 18:08:42.984: E/AndroidRuntime(31508):    at android.database.sqlite.SQLiteQuery.<init>(SQLiteQuery.java:37)
04-09 18:08:42.984: E/AndroidRuntime(31508):    at android.database.sqlite.SQLiteDirectCursorDriver.query(SQLiteDirectCursorDriver.java:44)
04-09 18:08:42.984: E/AndroidRuntime(31508):    at android.database.sqlite.SQLiteDatabase.rawQueryWithFactory(SQLiteDatabase.java:1314)
04-09 18:08:42.984: E/AndroidRuntime(31508):    at android.database.sqlite.SQLiteDatabase.rawQuery(SQLiteDatabase.java:1253)
04-09 18:08:42.984: E/AndroidRuntime(31508):    at com.Swap.RR.SubjectsDatabase.getSubjects(SubjectsDatabase.java:66)
04-09 18:08:42.984: E/AndroidRuntime(31508):    at com.Swap.RR.Add_Notes.onCreate(Add_Notes.java:32)
04-09 18:08:42.984: E/AndroidRuntime(31508):    at android.app.Activity.performCreate(Activity.java:5122)
04-09 18:08:42.984: E/AndroidRuntime(31508):    at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1146)
04-09 18:08:42.984: E/AndroidRuntime(31508):    at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2328)
04-09 18:08:42.984: E/AndroidRuntime(31508):    ... 11 more

请帮我找出我的代码有什么问题。感谢 Adavnce!!

最佳答案

这是一个简单的修复:你在这里错过了一个空格(并且有一个额外的下划线):

"CREATE_TABLE" + TABLE_SUBJECTS + "("

还有这里(还有额外的下划线)

SUBJECT_ID + "INTEGER_PRIMARY_KEY, "

这里

SUBJECT_NAME + "TEXT"

它应该是:

"CREATE TABLE " + TABLE_SUBJECTS + " (" // Note: NO UNDERSCORE!

和

SUBJECT_ID + " INTEGER PRIMARY KEY, " // Note: NO UNDERSCORES!

和

SUBJECT_NAME + " TEXT"

由于错误的 CREATE TABLE 语法，未创建表。

关于java - Android - SQLiteDatabase 没有这样的表错误(代码 1)，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/22962891/

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