如何修复 'SQLite No Column Exception'？

Question

我正在开发一个 android 应用程序，它将登录的用户信息保存在 SQLite 中。但我面临着奇怪的问题。在我的 DBHelper class create table 函数中创建得很好，插入函数不会抛出任何异常但是当我尝试从我的 SQL Lite DB 中检索数据时它抛出异常

no such column: officer (Sqlite code 1):, while compiling: Select * from User where userId=officer, (OS error - 2:No such file or directory)

我多次尝试更改数据库名称和版本，但没有任何效果。我试图从我的 android 设备查看数据库文件以确保我的 table 是否创建正常但是当我在我的 phone 的 Android/data 文件夹中搜索时，所有应用程序包名称都显示出来在那里，但我的应用程序的包名称不在那里。

public class DBHelper extends SQLiteOpenHelper {
// Database Name
private static final String DATABASE_NAME = "CMDB.db";
private static final int DATABASE_VERSION = 2;
// Contacts table name
private static final String TABLE_USER = "User";
public static DBHelper dbHelper;


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

public static DBHelper getInstance(Context context) {
    if (dbHelper == null) {
        dbHelper = new DBHelper(context.getApplicationContext());
    }
    return dbHelper;
}

@Override
public void onCreate(SQLiteDatabase sqLiteDatabase) {
    createTables(sqLiteDatabase);
    Toast.makeText(App.context,"onCreate",Toast.LENGTH_SHORT).show();



}

private void createTables(SQLiteDatabase sqLiteDatabase) {
    try {
    sqLiteDatabase.execSQL(" CREATE TABLE " + TABLE_USER + " (" +
                "userId" + " TEXT PRIMARY KEY," + "userImage" + " TEXT NOT NULL," +
                "userRole" + " TEXT NOT NULL," + "token" + " TEXT NOT NULL," + "userName" + " TEXT NOT NULL,"  + "userEmail" + " TEXT NOT NULL," + "userAddress" + " TEXT NOT NULL," + "mobile" + " TEXT NOT NULL);"
        );
        Toast.makeText(App.context,"createTables",Toast.LENGTH_SHORT).show();
    }catch (Exception ex){
        Toast.makeText(App.context,ex.getMessage(),Toast.LENGTH_SHORT).show();

        ex.printStackTrace();
    }

}

@Override
public void onUpgrade(SQLiteDatabase sqLiteDatabase, int i, int i1) {

    dropTables(sqLiteDatabase);

    // Create tables again
    onCreate(sqLiteDatabase);
}

private void dropTables(SQLiteDatabase sqLiteDatabase) {
    sqLiteDatabase.execSQL("DROP TABLE IF EXISTS " + TABLE_USER);

}

public void saveUserToDB(User user) {
    try {
        SQLiteDatabase db = this.getWritableDatabase();

        ContentValues values = new ContentValues();
        values.put("userId", user.userID);
        values.put("userImage", user.userImage);
     values.put("userRole", user.userRole);
        values.put("token", user.token);
        values.put("UserName", user.UserName);
        values.put("userEmail", user.userEmail);
        values.put("userAddress", user.userAddress);
        values.put("mobile", user.mobile);

        db.insert(TABLE_USER, null, values);
    } catch (Exception ex) {
        ex.printStackTrace();
    }
}

public User getUserFromDB(String userid) {
    User user = new User();
    try {
        SQLiteDatabase db = this.getReadableDatabase();
        String query = "Select * from " + TABLE_USER + " where userId=" +userid+ "";

        Cursor cursor = db.rawQuery(query, null);
        if (cursor != null) {
            cursor.moveToFirst();

            user.userID = cursor.getString(0);
            user.userImage = cursor.getString(1);
         user.userRole = cursor.getString(2);
            user.token = cursor.getString(3);
            user.UserName = cursor.getString(4);
            user.userEmail = cursor.getString(5);
            user.userAddress = cursor.getString(6);
            user.mobile = cursor.getString(7);
        }
    } catch (Exception ex) {
        ex.printStackTrace();
    }
    return user;

}

public void updateUser(User user, String userId) {
    SQLiteDatabase db = this.getWritableDatabase();
    ContentValues contentValues = new ContentValues();
    Gson gson = new Gson();
    String userJson = gson.toJson(user);
    contentValues.put("user", userJson);
    db.update(TABLE_USER, contentValues, "userId=" + userId, null);
}

public void updateUser(User user) {
    SQLiteDatabase db = this.getWritableDatabase();
    ContentValues cv = new ContentValues();
    cv.put("userId", user.userID);
    cv.put("userImage", user.userImage);
  cv.put("userRole", user.userRole);
    cv.put("token", user.token);
    cv.put("UserName", user.UserName);

    cv.put("userEmail", user.userEmail);
    cv.put("userAddress", user.userAddress);
    cv.put("mobile", user.mobile);

    db.update(TABLE_USER, cv, "userId=" + user.userID, null);
}}

我希望 SQLite 数据库与用户 table 和提到的列一起创建。还需要查看 Android Device.

中的 .db 文件

Answer 1

请post完整的错误跟踪，以便我们正确检查错误。从上面的代码和解释中我可以看到以下查询的一种可能性

sqLiteDatabase.execSQL(" CREATE TABLE " + TABLE_USER + " (" +
                "userId" + " TEXT PRIMARY KEY," + "userImage" + " TEXT NOT NULL," +
                "userRole" + " TEXT NOT NULL," + "token" + " TEXT NOT NULL," + "userName" + " TEXT NOT NULL,"  + "userEmail" + " TEXT NOT NULL," + "userAddress" + " TEXT NOT NULL," + "mobile" + " TEXT NOT NULL);"

密钥 userName 与下面代码中的 UserName 不同

public void updateUser(User user) {
    SQLiteDatabase db = this.getWritableDatabase();
    ContentValues cv = new ContentValues();
    cv.put("userId", user.userID);
    cv.put("userImage", user.userImage);
  cv.put("userRole", user.userRole);
    cv.put("token", user.token);
    cv.put("UserName", user.UserName);

    cv.put("userEmail", user.userEmail);
    cv.put("userAddress", user.userAddress);
    cv.put("mobile", user.mobile);

    db.update(TABLE_USER, cv, "userId=" + user.userID, null);
}}

注意：数据库中的列名始终区分大小写。

Answer 2

根据您提到的例外情况：

"no such column: officer (Sqlite code 1): , while compiling: Select * from User where userId=officer, (OS error - 2:No such file or directory)"

userId 的值有误，即 officer。

尝试在其前后添加单引号，如下所示：

String query = "Select * from " + TABLE_USER + " where userId='" + userid + "'";

如何修复 'SQLite No Column Exception'？

How to fix 'SQLite No Column Exception'?

android

android-sqlite

android-package-managers

android-database

android-flavors