Question

Hy guys，

我有关于SQL查询的错误。我找不到错误，我认为它来自于我创建表格的那一刻。如果你能帮助我，那就太好了。

public class dbVariablesCreate {
public static final String DB_NAME = "com.todolist.vladmac.mytodolist.db";
public static final int DB_VERSION = 1;

public class TaskEntry implements BaseColumns {
    public static final String TABLE = "table_task";
    public static final String COL_TASK = "task";
    public static final String COL_COLOR = "colo";
}

}

    public class dbRequery extends SQLiteOpenHelper {

public dbRequery(Context context) {
    super(context, dbVariablesCreate.DB_NAME, null, dbVariablesCreate.DB_VERSION);
}

@Override
public void onCreate(SQLiteDatabase db) {
  /*  String createTable = "CREATE TABLE " + dbVariablesCreate.TaskEntry.TABLE + " ( " +
            dbVariablesCreate.TaskEntry._ID + " INTEGER PRIMARY KEY AUTOINCREMENT, " +
            dbVariablesCreate.TaskEntry.COL_TASK+" TEXT, "+dbVariablesCreate.TaskEntry.COL_COLOR+ " TEXT);";*/

    db.execSQL("CREATE TABLE " + dbVariablesCreate.TaskEntry.TABLE + " ( " + dbVariablesCreate.TaskEntry._ID + " INTEGER PRIMARY KEY AUTOINCREMENT, " + dbVariablesCreate.TaskEntry.COL_TASK + " TEXT, " + dbVariablesCreate.TaskEntry.COL_COLOR + " TEXT);");
}

@Override
public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
    db.execSQL("DROP TABLE IF EXISTS " + dbVariablesCreate.TaskEntry.TABLE);
    onCreate(db);
}

}

重新查询

Cursor cursor = db.rawQuery("SELECT " + dbVariablesCreate.TaskEntry._ID + ", " + dbVariablesCreate.TaskEntry.COL_TASK ", " + dbVariablesCreate.TaskEntry.COL_COLOR + " FROM " + dbVariablesCreate.TaskEntry.TABLE, null);

感谢您的帮助。

Answer 1

看起来你错过了添加这个

public static final String _ID = "_id";

你的代码？ TaskEntry

public class dbVariablesCreate {
public static final String DB_NAME = "com.todolist.vladmac.mytodolist.db";
public static final int DB_VERSION = 1;

public class TaskEntry implements BaseColumns {
    public static final String TABLE = "table_task";
    public static final String _ID = "_id";
    public static final String COL_TASK = "task";
    public static final String COL_COLOR = "colo";
}

此处从查询中删除突出显示的;

db.execSQL（“CREATE TABLE”+ dbVariablesCreate.TaskEntry.TABLE +“（”+ dbVariablesCreate.TaskEntry._ID +“INTEGER PRIMARY KEY AUTOINCREMENT，”+ dbVariablesCreate.TaskEntry.COL_TASK +“TEXT，”+ dbVariablesCreate.TaskEntry .COL_COLOR +“TEXT）;”）;

使用这个

db.execSQL("CREATE TABLE " + dbVariablesCreate.TaskEntry.TABLE + " ( " + dbVariablesCreate.TaskEntry._ID + " INTEGER PRIMARY KEY AUTOINCREMENT, " + dbVariablesCreate.TaskEntry.COL_TASK + " TEXT, " + dbVariablesCreate.TaskEntry.COL_COLOR + " TEXT)");

Answer 2

尝试使用此重新查询

public Cursor queryAll(){
        //get a READABLE database instance:
        SQLiteDatabase db = dbRequery.getReadableDatabase();

        //query all:
        //db.query(table, columns, selection, selectionArgs, groupBy, having, orderBy);
        Cursor cursor = db.query(
                dbVariablesCreate.TaskEntry.TABLE,null,
                null,
                null,
                null,
                null,
             null );
        return cursor ;
    }

E / SQLiteLog：（1）没有这样的列：colo

2 个答案:

使用这个