在执行一个SQLite的查询 [英] Performing a Lookup on SQLite

问题描述

http://postimg.org/image/4vozphdk7/

因此​​，这些都是我的表;

保存我数据以这样的方式，该Workout_ID（第二图）引用Workout_ID在顶部图。

我需要什么？ - 我怎么能查询什么Workout_ID 2，输出字符串，当涉及到我的显示表

在SQLite的完成，这可能吗？

codeD表列名：

  DATE_ID = date_of_workout_id
日期= date_of_workout
workout_name = workout_name
date_of_workout = DateofWorkout
workout_table = WorkoutTable
workout_id（日期的一个）= name_of_workout
workout_id（WorkoutTables的一个）= workout_id
 

公共字符串测试（字符串WorkoutSelectedNameInfo）{

  // TODO自动生成方法存根
    柱重量=;
    打开（）;
    ourDatabase = ourhelper.getReadableDatabase（）;    光标C = ourDatabase.rawQuery（SELECT date_of_workout_id，
   date_of_workout，workout_name FROM DateofWorkout JOIN WorkoutTable ON
 DateofWorkout.name_of_workout = WorkoutTable.workout_id，NULL）;
    INT iWeight = c.getColumnIndex（KEY_WORKOUT_NAME）;
             而（c.moveToNext（））
        {
            重量=重量+ c.getString（iWeight）+\\ n;
        }
    c.close（）;
    ourDatabase.close（）;    的System.out.println（重量）;    返回重量;}
 

解决方案

更​​新答案：

尝试更改

  

光标C = ourDatabase.rawQuery（SELECT date_of_workout_id，结果
  date_of_workout，workout_name FROM DateofWorkout JOIN WorkoutTable ON
  DateofWorkout.name_of_workout = WorkoutTable.workout_id，NULL）;

到

  

光标C = ourDatabase.rawQuery（SELECT date_of_workout_id，结果
  date_of_workout，workout_name FROM DateofWorkout JOIN WorkoutTable ON
   DateofWorkout.workout_id = WorkoutTable.workout_id ，NULL）;

问题也许是因为你比较 name_of_workout 从 workout_id

一个简单的内心或许加入？

 选择dow.date_id，dow.date，w.name
从锻炼W，date_of_workout道
其中，w.workout_id = dow.workout_id
 

http://postimg.org/image/4vozphdk7/

So these are my tables;

I save my data in such a way that the Workout_ID (second figure) references the Workout_ID in the top figure.

What i need - How can i 'Look up' what Workout_ID 2 is and output the string, when it comes to displaying my table?

Done in SQLite, is this possible?

Coded Table column Names:

date_id = date_of_workout_id
date = date_of_workout
workout_name = workout_name
date_of_workout = DateofWorkout
workout_table = WorkoutTable
workout_id(date's one) = name_of_workout
workout_id(WorkoutTables's one) = workout_id

public String test(String WorkoutSelectedNameInfo) {

    // TODO Auto-generated method stub
    String Weight = "";
    open();
    ourDatabase = ourhelper.getReadableDatabase();



    Cursor c = ourDatabase.rawQuery("SELECT date_of_workout_id, 
   date_of_workout, workout_name FROM DateofWorkout JOIN WorkoutTable ON 
 DateofWorkout.name_of_workout = WorkoutTable.workout_id", null);
    int iWeight = c.getColumnIndex(KEY_WORKOUT_NAME);
             while(c.moveToNext())
        {
            Weight = Weight + c.getString(iWeight) + "\n";
        }


    c.close();
    ourDatabase.close();

    System.out.println(Weight);

    return Weight;



}

解决方案

Updated Answer:

Try changing

Cursor c = ourDatabase.rawQuery("SELECT date_of_workout_id,
date_of_workout, workout_name FROM DateofWorkout JOIN WorkoutTable ON DateofWorkout.name_of_workout = WorkoutTable.workout_id", null);

to

Cursor c = ourDatabase.rawQuery("SELECT date_of_workout_id,
date_of_workout, workout_name FROM DateofWorkout JOIN WorkoutTable ON DateofWorkout.workout_id = WorkoutTable.workout_id", null);

the problem maybe is because you are comparing name_of_workout from workout_id.

A simple inner join perhaps?

select dow.date_id, dow.date, w.name
from workout w, date_of_workout dow
where w.workout_id = dow.workout_id

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