Question

这里我有一个ID数组，并且只有在数组中有1个ID时，update方法才有效，但是如果我输入2-3，它会给我一个错误..类似：Too many bind arguments. 4 arguments were provided but the statement needs 2 arguments这行得通。我想在同一列中为不同的ID设置相同的值。

    ContentValues values = new ContentValues();
    values.put(DataEntry.COLUMN_DATA, "1");
    String selection = DataEntry._ID + "=?";
    String[] selectionArgs = selectedData.toArray(new String[selectedData.size()]);
    // To be a bit more clear the above line looks like this:
    // String[] selectionArgs = { 1, 2, 3, 4, 5 }; String array of IDs which varies 

    int rowsAffected = getContentResolver().update(DataEntry.CONTENT_URI, values, selection, selectionArgs);

更新方法如下：

    SQLiteDatabase db = mDbHelper.getWritableDatabase();
    int rowsUpdated = db.update(DataEntry.TABLE_NAME, values, selection, selectionArgs);

Answer 1

我相信您可以使用：-

ContentValues values = new ContentValues();
values.put(DataEntry.COLUMN_DATA, "1");
String selection = DataEntry._ID + "=?";
String[] selectionArgs = selectedData.toArray(new String[selectedData.size()]);
for each(String s: selectionArgs) {
    int rowsAffected = getContentResolver().update(DataEntry.CONTENT_URI, values, selection, new String[]{s});
}

或者您可以使用WHERE IN (list of id's)，它可能与：-

相似

ContentValues values = new ContentValues();
values.put(DataEntry.COLUMN_DATA, "1");
String selection " IN (?)";
String[] selectionArgs = selectedData.toArray(new String[selectedData.size()]);
StringBuilder sb = new StringBuilder();
for (int i=0; i < selectionArgs.length(); i++) {
    sb.append(selectionArgs[i]);
    if (i < (selectionArgs.length - 1)) {
        sb.append(",");
    }
}        
int rowsAffected = getContentResolver().update(DataEntry.CONTENT_URI, values, selection, new String[]{sb.toString()});

当然，您可以循环使用x个占位符。这将是：-

ContentValues values = new ContentValues();
values.put(DataEntry.COLUMN_DATA, "1");
String[] selectionArgs = selectedData.toArray(new String[selectedData.size()]);
StringBuilder sb = new StringBuilder("IN (");
for (int i=0; i < selectionArgs.length(); i++) {
    if (i < (selectionArgs.length() - 1) {
        sb.append("?,");
    } else {
        sb.append("?)");
    }
}        
int rowsAffected = getContentResolver().update(DataEntry.CONTENT_URI, values, sb.toString, selectionArgs);

请注意，这是原理代码，未经测试，因此可能包含一些错误。

问：如何使用不同ID的相同数据更新1列（android）

1 个答案: