Question

背景 - 我试图检索由州过滤的拍卖列表。我试图检索拍卖日期和拍卖名称。

我从列表视图中获取状态名称 - 正确传递状态值（我已经注释掉构建状态列表并使用Toast验证好值的函数的名称）

我的问题发生在fillAuctionsList（String editAuctionState）;

public void fillAuctionsList(String editAuctionState){
    //sql Query - editAuctionState is the State selected

    SQLiteQueryBuilder queryBuilder = new SQLiteQueryBuilder();
    //set the table to the Auction
    queryBuilder.setTables(Auctions.AUCTIONS_TABLE_NAME);

    // build the return columns for my listview
    String asColumnsToReturn[]= {
            Auctions.AUCTIONS_TABLE_NAME + "." + Auctions.AUCTIONS_AUCTION_NAME,
            Auctions.AUCTIONS_TABLE_NAME + "." + Auctions.AUCTIONS_DATE,
            Auctions.AUCTIONS_TABLE_NAME + "." + Auctions.AUCTIONS_STATE,
            Auctions.AUCTIONS_TABLE_NAME + "." + Auctions._ID}; 
    //end of build columns to return

    //build the where statement based on the Auction State
    String howToFilter[]={editAuctionState};

    //build the cursor

    mCursor = queryBuilder.query(mDB, asColumnsToReturn, Auctions.AUCTIONS_STATE + "=?", howToFilter,null, null, null);

    //manage the cursor
    startManagingCursor(mCursor);

    int HowManyRecords = mCursor.getCount();
    if(HowManyRecords==0){
        Toast.makeText(getApplicationContext(),"No Records Found",Toast.LENGTH_LONG).show();
        finish();
    }

此后更多光标代码。

我在querybuilder语句中得到Null指针异常错误 - 应用程序似乎永远不会到达代码来计算记录数。

任何建议表示赞赏。感谢

Answer 1

问题解决了......

我有一个'呃'的时刻，并没有打算真正打开数据库。

在android.database.sqlite.SQLiteQueryBuilder.query（SQLiteQueryBuilder.java）中出现空指针异常

1 个答案: