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在Android上创建SQLite数据库中的表格

androidsqliteandroid-logcat
8
以下是代码创建应用程序数据库的内容。我们发现它似乎没有创建表格，因此我们在尝试插入和读取表格数据时程序崩溃。我们已经尝试了所有可能的方法，添加System.out.println的语句以查看程序执行到哪一步了。我们可以看到程序已经执行到了tophere这里，但是没有执行下面的downhere，所以我们猜测原因可能出在这里。我们使用DDMS检查数据库是否在正确的文件夹中，因此应该存在数据库，但是某些原因导致它无法找到它（见日志中的第2行和第3行）。
有什么想法吗？
以下是错误日志： 
04-27 10:45:46.768: I/System.out(6441): tophere
04-27 10:45:46.772: I/SqliteDatabaseCpp(6441): sqlite返回：错误代码=1，消息=未知数据库NOPO，db=/data/data/dmri.nopo/databases/NOPO
04-27 10:45:46.772: W/System.err(6441): android.database.sqlite.SQLiteException: 未知数据库NOPO: ，在编译时：创建表if not exists NOPO.log (time INTEGER primary key, text TEXT not null);
04-27 10:45:46.792: W/System.err(6441):     at android.database.sqlite.SQLiteCompiledSql.native_compile(Native Method)
04-27 10:45:46.792: W/System.err(6441):     at android.database.sqlite.SQLiteCompiledSql.(SQLiteCompiledSql.java:68)
04-27 10:45:46.811: W/System.err(6441):     at android.database.sqlite.SQLiteProgram.compileSql(SQLiteProgram.java:134)
04-27 10:45:46.811: W/System.err(6441):     at android.database.sqlite.SQLiteProgram.compileAndbindAllArgs(SQLiteProgram.java:361)
04-27 10:45:46.811: W/System.err(6441):     at android.database.sqlite.SQLiteStatement.acquireAndLock(SQLiteStatement.java:260)
04-27 10:45:46.811: W/System.err(6441):     at android.database.sqlite.SQLiteStatement.executeUpdateDelete(SQLiteStatement.java:84)
04-27 10:45:46.811: W/System.err(6441):     at android.database.sqlite.SQLiteDatabase.executeSql(SQLiteDatabase.java:1899)
04-27 10:45:46.823: W/System.err(6441):     at android.database.sqlite.SQLiteDatabase.execSQL(SQLiteDatabase.java:1839)
04-27 10:45:46.823: W/System.err(6441):     at dmri.nopo.DBAdapter$DatabaseHelper.onOpen(DBAdapter.java:67)
04-27 10:45:46.823: W/System.err(6441):     at android.database.sqlite.SQLiteOpenHelper.getWritableDatabase(SQLiteOpenHelper.java:180)
04-27 10:45:46.902: W/System.err(6441):     at dmri.nopo.DBAdapter.open(DBAdapter.java:86)
04-27 10:45:46.912: W/System.err(6441):     at dmri.nopo.LogManager.readLogFile(LogManager.java:32)
04-27 10:45:46.912: W/System.err(6441):     at dmri.nopo.LogActivity.onCreate(LogActivity.java:25)
04-27 10:45:46.921: W/System.err(6441):     at android.app.Activity.performCreate(Activity.java:4465)
04-27 10:45:46.921: W/System.err(6441):     at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1049)
04-27 10:45:46.931: W/System.err(6441):     at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1920)
04-27 10:45:46.931: W/System.err(6441):     at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:1981)
04-27 10:45:46.941: W/System.err(6441):     at android.app.ActivityThread.access$600(ActivityThread.java:123)
04-27 10:45:46.941: W/System.err(6441):     at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1147)
04-27 10:45:46.953: W/System.err(6441):     at android.os.Handler.dispatchMessage(Handler.java:99)
04-27 10:45:46.953: W/System.err(6441):     at android.os.Looper.loop(Looper.java:137)
04-27 10:45:46.972: W/System.err(6441):     at android.app.ActivityThread.main(ActivityThread.java:4424)
04-27 10:45:46.972: W/System.err(6441):     at java.lang.reflect.Method.invokeNative(Native Method)
04-27 10:45:46.972: W/System.err(6441):     at java.lang.reflect.Method.invoke(Method.java:511)
04-27 10:45:46.982: W/System.err(6441):     at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:
5个回答
4
这将有助于你，我已经尝试过了，它也在正常运行。
这只是一个例子。
public class DatabaseMarks {

    public static final String KEY_STUID = "stuid";
    public static final String KEY_SUB1 = "subject_one";
    public static final String KEY_SUB2 = "subject_two";
    public static final String KEY_SUB3= "subject_three";
    public static final String KEY_MARKS1= "marks_one";
    public static final String KEY_MARKS2 = "marks_two";
    public static final String KEY_MARKS3 = "marks_three";

    private static final String DATABASE_NAME = "Student";
    private static final String DATABASE_MARKSTABLE = "StudentMarks";
    private static final int DATABASE_VERSION = 1;

    private DbHelper ourHelper;
    private final Context ourContext;
    private SQLiteDatabase ourDatabase;

    private static class DbHelper extends SQLiteOpenHelper{

        public DbHelper(Context context) {
            super(context, DATABASE_NAME, null, DATABASE_VERSION);
            // TODO Auto-generated constructor stub
        }

        @Override
        public void onCreate(SQLiteDatabase db) {
            // TODO Auto-generated method stub
                db.execSQL(" CREATE TABLE " + DATABASE_MARKSTABLE + " (" +
                    KEY_STUID + " TEXT PRIMARY KEY, " +
                    KEY_SUB1 + " TEXT NOT NULL, " +
                    KEY_SUB2 + " TEXT NOT NULL, " +
                    KEY_SUB3 + " TEXT NOT NULL, " +
                    KEY_MARKS1 + " INTEGER NOT NULL, " +
                    KEY_MARKS2 + " INTEGER NOT NULL, " +
                    KEY_MARKS3 + " INTEGER NOT NULL);"
            );
        }

        @Override
        public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
            // TODO Auto-generated method stub

            db.execSQL("DROP TABLE IF EXISTS " + DATABASE_MARKSTABLE);
            onCreate(db);
        }

    }
    public DatabaseMarks(Context c){
        ourContext = c;
    }
    public DatabaseMarks open()throws SQLException{
        ourHelper = new DbHelper(ourContext);
        ourDatabase = ourHelper.getWritableDatabase();
        return this;
    }
    public void close(){
        ourHelper.close();
    }
    public long createInsert(String stuid, String subject1, String subject2,
            String subject3, String marks1, String marks2, String marks3) {
        // TODO Auto-generated method stub
        ContentValues cv = new ContentValues();
        cv.put(KEY_STUID, stuid);
        cv.put(KEY_SUB1, subject1);
        cv.put(KEY_SUB2, subject2);
        cv.put(KEY_SUB3, subject3);
        cv.put(KEY_MARKS1, marks1);
        cv.put(KEY_MARKS2, marks2);
        cv.put(KEY_MARKS3, marks3);
        return ourDatabase.insert(DATABASE_MARKSTABLE, null, cv);

    }
这里的测试很有帮助，如果出现错误，我可以重复测试以确认是否使用了原始数据？ - Samer
3
首先，我建议在Android中使用android.util.Log来记录异常。
其次 - 我怀疑您创建了错误名称的表。您的错误提示查询无法找到“log”，但我看到您在“CREATE”语句中进行了一些连接。这可能是原因。
您可以检查实际为您创建的内容。通过查看创建的sqlite数据库。
您可以尝试：
1. adb shell 2. cd /data/data/ /databases 3. sqlite3 4. .tables
adb shell 应该从 Android Studio 中的终端中运行吗？ - user4084811
1
@ColeTrumbo 你可以使用任何终端，但在执行adb命令之前，你必须导航到<sdk位置>/platform-tools。 - Zoe stands with Ukraine
1

请从您的SQL中删除DATABASE_NAME部分。

如果您想要将数据库名称设置为NOPO，并且想要创建一个名为log的表，则应执行以下操作：

private static class DatabaseHelper extends SQLiteOpenHelper {

    DatabaseHelper(Context context) {
        super(context, "NOPO", null, 2);
    }

    @Override
    public void onCreate(SQLiteDatabase db) {
        db.execSQL("CREATE TABLE " + "log" + " ("
                + KEY_TIME +" INTEGER primary key, "
                + KEY_TEXT +" TEXT not null);");
    }

    @Override
    public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
        Log.w(TAG, "Upgrading database from version " + oldVersion + " to "
                + newVersion + ", which will destroy all old data");
        db.execSQL("DROP TABLE IF EXISTS log");
        onCreate(db);
    }
}

super(context, "NOPO", null, 2); 使得这个DatabaseHelper对象只在NOPO数据库环境中，因此您无需在SQL中指定它。

附注：我硬编码了一些东西，您应该避免这样做。

为什么要处理onCreate和onOpen方法？我是一名iOS开发人员，正在尝试“翻译”（这么说吧）我的cocoa库，以便可以在Android上使用它。我需要在运行时创建一个SQLite数据库。由于这是我创建的一个库，我没有一个activity。看起来我不能在没有activity的情况下创建DB，这是正确的吗？ - Daniel
0

公共类LoginDataBaseAdapter { static final String DATABASE_NAME = "login.db";

    static final int DATABASE_VERSION = 1;

    public static final int NAME_COLUMN = 1;

    // TODO: Create public field for each column in your table.
    // SQL Statement to create a new database.

    static final String DATABASE_CREATE = "create table "+"LOGIN"+
                                 "( " +"ID"+" integer primary key autoincrement,"+ "USERNAME  text,PASSWORD text,UNAME text); ";

    // Variable to hold the database instance
    public  SQLiteDatabase db;

    // Context of the application using the database.
    private final Context context;

    // Database open/upgrade helper
    private DataBaseHelper dbHelper;

    public  LoginDataBaseAdapter(Context _context) 
    {
        context = _context;
        dbHelper = new DataBaseHelper(context, DATABASE_NAME, null, DATABASE_VERSION);

    }
    public  LoginDataBaseAdapter open() throws SQLException 
    {
        db = dbHelper.getWritableDatabase();
        return this;
    }
    public void close() 
    {
        db.close();
    }

    public  SQLiteDatabase getDatabaseInstance()
    {
        return db;
    }
-1
            public class DBHandler extends SQLiteOpenHelper {
                private static String DATABASE_NAME = "mydb";
                private static int DATABASE_VERSION = 1;

                String TABLE_NAME = "Student";

                String KEY_ID = "id";
                String KEY_STUDENT_NAME = "name";
                String KEY_STUDENT_MARKS = "marks";

            public DBHandler(Context context) {
                    super(context, DATABASE_NAME, null, DATABASE_VERSION);
                }

        @Override
            public void onCreate(SQLiteDatabase db) {
                // creating table
                String query = "CREATE TABLE " + TABLE_NAME +
                        " ( " +
                        KEY_ID + " INTEGER PRIMARY KEY," +
                        KEY_STUDENT_NAME + " TEXT," +
                        KEY_STUDENT_MARKS + " INTEGER"
                        " ) ";
                db.execSQL(query);

            // insertion in the table
            ContentValues values = new ContentValues();
            values.put(KEY_QUESTION_ID, "1");
            values.put(KEY_STUDENT_NAME , "abc");
            values.put(KEY_STUDENT_MARKS , "95");
            db.insert(TABLE_NAME, null, values);

            values.put(KEY_QUESTION_ID, "2");
            values.put(KEY_STUDENT_NAME , "def");
            values.put(KEY_STUDENT_MARKS , "93");
            db.insert(TABLE_NAME, null, values);
    }
        @Override
        public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
            // TODO Auto-generated method stub

            db.execSQL("DROP TABLE IF EXISTS " + TABLE_NAME);
            // Create tables again
            onCreate(db);
        }
     // retrieve date
     List<Student> getAllData(int Id) {

            List<Student> student = new ArrayList<Student>();
            // Select All Query
            String selectQuery = "SELECT * FROM " + TABLE_NAME + "    WHERE KEY_ID =" + "'" + Id + "'";

            SQLiteDatabase db = this.getWritableDatabase();

            Cursor cursor = db.rawQuery(selectQuery, null);

            // looping through all rows and adding to list
            if (cursor.moveToFirst()) {
                do {
                    Student std = new Student();
                    u.setId(cursor.getInt(0));
                    u.setStudentName(cursor.getString(1));
                    u.setMarks(cursor.getString(2));

                    student.add(std);
                } while (cursor.moveToNext());
            }
            // return student list
            return student;
        }
    }

     public class Student {

        public static int Id;
        public static String studentName;
        public static int marks;

        public int getId() {
            return Id;
        }

        public static void setId(int id) {
            Id = id;
        }

        public String getStudentName() {
            return studentName;
        }

        public static void setStudentName(String studentName) {
            Student.studentName = studentName;
        }

        public int getMarks() {
            return marks;
        }

        public static void setMarks(int marks) {
            Student.marks = marks;
        }
    }

    public class MainActivity extends AppCompatActivity {

        @Override
        protected void onCreate(Bundle savedInstanceState) {
            super.onCreate(savedInstanceState);
            setContentView(R.layout.activity_main);

            DBHandler db = new DBHandler(getApplicationContext());
            List<Student> std = new ArrayList<Student>();
            rl = db.getAllData(1);
           for (Student s : std) {
               Log.v("Id",s.getId());
               Log.v("Name",s.getStudentName());
               Log.v("Marks",s.getMarks());
       }
    }
}
2
请详细说明您的答案。 - maRtin
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