Question

我在我的本地db（sqlite）中插入一些日期。但是当我想选择这个数据时，游标不是构建xml并跳过这个块。我的sqlite中有一行。你有什么想法吗？

这是我的代码：`

public void insertMessages(int msgid,String msgdesc, String date, int createdby,int to) {
    SQLiteDatabase myDatabase = this.getWritableDatabase();

            String query = "INSERT INTO Messages (_id,msgdesc,date,createdby,sendto) "+
                           " VALUES ("+msgid+",'"+msgdesc+"','"+date+"',"+createdby+","+to+")";
            SQLiteStatement st = myDatabase.compileStatement(query);

    try {
        st.execute();
    } catch (SQLException e) {
        // TODO Auto-generated catch block
        e.printStackTrace();
    }

    myDatabase.close();
    Log.i("insert","insert Messages completed");
}




public String getMessages(int to) {
        SQLiteDatabase myDatabase = this.getWritableDatabase();
        String xml = null;

        try {

            String query = "SELECT _id,msgdesc,date,createdby,sendto from Messages Where sendto="+to+"";    
            Cursor cs = myDatabase.rawQuery(query, null);

            xml = "<messagelist>";
            *****if (cs.moveToFirst()) {*****
                do {
                    xml += "<messages>";
                    xml += "<msgid>"+cs.getInt(cs.getColumnIndex("_id"))+"</msgid>";
                    xml += "<msgdesc>"+cs.getString(cs.getColumnIndex("msgdesc"))+"</msgdesc>";
                    xml += "<date>"+cs.getString(cs.getColumnIndex("date"))+"</date>";
                    xml += "<createdby>"+cs.getInt(cs.getColumnIndex("createdby"))+"</createdby>";
                    xml += "<to>"+cs.getInt(cs.getColumnIndex("sendto"))+"</to>";
                    xml += "</messages>";
                } while (cs.moveToNext());
            }
            xml += "</messagelist>";
            cs.close();

        } catch (SQLException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
        myDatabase.close();


        Log.i("select","select completed");
        return xml;
    }`

Answer 1

"SELECT _id,msgdesc,date,createdby,sendto from Messages Where sendto="+to+"";

您必须使用单引号分隔字符串常量。试试这个

"SELECT _id,msgdesc,date,createdby,sendto from Messages Where sendto = '" + to + "'";

更好的方法是使用参数化查询。

http://sqlite.phxsoftware.com/forums/t/83.aspx

光标在SQLite中不起作用

1 个答案: