SQLite游标查询错误“like”和“==”不处理内容提供程序“selection”定义

在我的SQLite选择器定义中，这可能是一个愚蠢的错误，但似乎无法从到目前为止发布的类似问题和错误中看出这一点。我可能犯了一个愚蠢的错误，但我一生都找不到。请让我知道，如果你需要更多的信息，以便能够帮助

因此，这种方法非常有效：

selection = "((" +
                TransContract.TransEntry.COLUMN_DATE + " > " +
                Long.toString(dateOutput) + ") AND (" +
                TransContract.TransEntry.COLUMN_DATE + " <= " + Long.toString(dateOutputEnd) + "))";

或者以这种方式：

selection = TransContract.TransEntry.COLUMN_CATEGORY + " like " + '%'+
                "Transport General" + "%";

selection = TransContract.TransEntry.COLUMN_CATEGORY + " == " +
                "Transport General";

我收到E/AndroidRuntime：致命异常

我的光标查询：

cursor = database.query(
                    TransContract.TransEntry.TABLE_NAME,
                    projection,
                    selection,
                    selectionArgs,
                    null,
                    null,
                    sortOrder);

找到类别列的My DbHelper：

String SQL_CREATE_ENTRIES =
            "CREATE TABLE " + TransContract.TransEntry.TABLE_NAME + " (" +
                    TransContract.TransEntry._ID + " INTEGER PRIMARY KEY AUTOINCREMENT, " +
                    TransContract.TransEntry.COLUMN_AMOUNT + " REAL, " +
                    TransContract.TransEntry.COLUMN_TYPE + " INTEGER NOT NULL DEFAULT 0, " + // debit, credit
                    TransContract.TransEntry.COLUMN_ACCOUNT + " INTEGER, " + // wallet, savings, more later.
                    TransContract.TransEntry.COLUMN_ACCOUNT_FROM + " INTEGER, " + // defaults from wallet 0
                    TransContract.TransEntry.COLUMN_ACCOUNT_TO + " INTEGER, " + // defaults back to wallet 0
                    TransContract.TransEntry.COLUMN_CATEGORY + " TEXT, " +
                    TransContract.TransEntry.COLUMN_TITLE + " TEXT, " +
                    TransContract.TransEntry.COLUMN_DATE + " INTEGER, " +
                    TransContract.TransEntry.COLUMN_RECURRING + " INTEGER NOT NULL DEFAULT 0," +
                    TransContract.TransEntry.COLUMN_FREQUENCY + " TEXT," +
                    TransContract.TransEntry.COLUMN_END_DATE + " INTEGER" +
                    ");";

编辑

谢谢你的评论，我应该更具体一些！我的堆栈跟踪确实是一个语法错误，它来自我正在粘贴的新代码行

Caused by: android.database.sqlite.SQLiteException: near "General": syntax error (code 1): , while compiling: SELECT _id, category, title, amount, type, date FROM transactions WHERE category == Transport General ORDER BY date DESC 

问题是字符串的双引号中有单引号，谢谢@Ton Plooij，但奇怪的是比较值不需要单引号

以下是工作解决方案：

selection = TransContract.TransEntry.COLUMN_CATEGORY + " = " +
                "'Transport General'";  

---

我不知道编程语言是如何工作的，但两个失败的SQlite查询字符串似乎都创建得不正确。like查询应类似于TransContract.TransEntry.COLUMN_类别，类似于“%Transport General%”。在查询中构造比较字符串时，不使用开始和结束单引号。第二个查询有两个问题：“==”应该是一个“=”并且比较值没有用单引号括起来