Question

我在向db表中插入行时遇到问题。我跟着代码：

try {
  myDB = jDB.getInstance(getApplicationContext()).db;

  myDB.beginTransaction();
  String sSQL = "INSERT INTO kosik (mnozstvi, cena, idVyrobek) VALUES ('" +
          sMn + "', '" + sCena + "', '" + String.valueOf(iIDVyrobku) + "');";
  myDB.execSQL(sSQL, null);
  myDB.endTransaction();
} catch (SQLiteException e) {
  e.printStackTrace();
}

类jDB如下：

public class jDB {
private static jDB dbInstance = null;
public static String DB_PATH;
public static SQLiteDatabase db = null;
private static final String DATABASE_NAME = "db.sqlite";
.
.
.
public static jDB getInstance(Context context)
{
if (dbInstance  == null) 
{
  DB_PATH = "/data/data/" + context.getPackageName();
  // if not exists database, copy new from assets
  if (!isDataBaseExist())
  {
    try {
      copyDataBase(context);
    } catch (IOException ex)
    {
      Toast.makeText(context,
          "" + ex.getLocalizedMessage(), Toast.LENGTH_LONG).show();
    }
  }
  DB_PATH = DB_PATH + "/" + DATABASE_NAME;
  db = SQLiteDatabase.openDatabase(DB_PATH, null, SQLiteDatabase.OPEN_READWRITE);
  // create singleton object
  dbInstance = new jDB(context);
}
return dbInstance;
}

插入后，一切似乎都没问题，但没有行插入表...

我做错了什么？

谢谢，彼得

解决方案：

最后，有工作解决方案：

try {
    myDB = jDB.getInstance(getApplicationContext()).db;

    myDB.beginTransaction();
    ContentValues insertValues = new ContentValues();
    insertValues.put("idVyrobek", String.valueOf(iIDVyrobku));
    insertValues.put("mnozstvi", sMn);
    insertValues.put("cena", sCena);
    insertValues.put("poznamka", "");
    myDB.insertOrThrow("kosik", null, insertValues);
    myDB.setTransactionSuccessful();
  } catch (SQLiteException e) {
    e.printStackTrace();
  } finally {
    myDB.endTransaction();
}

非常感谢你帮助Bismark！

Answer 1

尝试在调用endTransaction（）之前添加setTransactionSuccessful（）。此外，我通常将endTransaction放在finally语句中，以避免SQLite出现问题：

myDB = jDB.getInstance(getApplicationContext()).db;
myDB.beginTransaction();
try {
    String sSQL = "INSERT INTO kosik (mnozstvi, cena, idVyrobek) VALUES ('" +
          sMn + "', '" + sCena + "', '" + String.valueOf(iIDVyrobku) + "');";
    myDB.execSQL(sSQL, null);
    myDB.setTransactionSuccessful();
} catch (SQLiteException e) {
    e.printStackTrace();
} finally {
    myDB.endTransaction();
}

Android - 将行插入SQLite DB

1 个答案: