Question

我正在尝试检查有效用户。但我得到以下Exception：

no such column: ABC(Code 1):, while compiling: SELECT _id, username, password 
FROM MyTable1 WHERE username=ABC

代码如下：

public int checkUser(String userName, String password) {
    int check = -1;
    int id = 2;
    String psword = new String();

    Cursor cursor = database.query(TABLE_NAME, allColumns, COLUMN_USER_NAME + "=" + userName, null, null, null, null);
    cursor.moveToFirst();
    Log.v(TAG, "After CURSOR!!");
    psword = cursor.getString(cursor.getColumnIndex(COLUMN_PASSWORD));
    Log.v(TAG, "pasword: " + psword);
    if (psword.equals(password)) {
        check = 1;
    }
    return check;
}

我做错了什么？请帮忙

Answer 1

如果用户名是varchar / text type，那么

 Cursor cursor = database.query(TABLE_NAME, allColumns, COLUMN_USER_NAME
            + "=" + '"+userName+"', null, null, null, null);

这是示例登录功能

 public boolean checkUser(String username, String password) throws SQLException
    {
     String whereClause = " USERNAME =  '"+userName+"' "; 

    try {
        open();// dbopen
        Cursor cursor = db.query(TABLE_NAME, allColumns,whereClause, null, null, null, null);
      }catch(Exception e){
            }
 }

或

public boolean checkUser(String username, String password) throws SQLException
    {
      Cursor mCursor = database.rawQuery("SELECT * FROM " + DATABASE_TABLE + " WHERE username=? AND password=?", new String[]{username,password});
        if (mCursor != null) {
          if(mCursor.getCount() > 0)
             {
            return true;
            }
        }
        return false;
        }

Answer 2

您应该在userName周围添加引号。您想要与字符串值“ABC”或“ABC”匹配的行我不记得哪些引号。如果您不放置引号，则与名为ABC的列匹配。

您应该使用prepares语句。这样可以避免许多问题。

在sqlite中检查有效的用户名和密码时获取异常

2 个答案: