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Thread: retrieve data from database using Hashmap (multiple values in one key)

  1. #1
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    Question retrieve data from database using Hashmap (multiple values in one key)

    hi i want to retrieve all data from the specific field in database using hashmap.. unfortunately, only the last value was retrieve.. what will i do?


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    Default Re: retrieve data from database using Hashmap (multiple values in one key)

    what will i do?
    Fix the logic in your code.
    If you don't understand my answer, don't ignore it, ask a question.

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    Default Re: retrieve data from database using Hashmap (multiple values in one key)

    You want to retrieve all data from a table in database, isn't it?
    For example:

    You have a table in database:
    table: Names
    id name
    --------------------------
    1 Adam
    2 Brian
    3 John
    4 Michael

    this code can retrieve all data from this table:

    ...
    Map<Integer, String> names = new HashMap<Integer, String>();
     
    ...
    Statement s = connection.createStatement();
    ResultSet r = s.executeQuery("SELECT * FROM Names");
     
    while(r.next()){
        Integer id = new Integer(r.getInt("id"));
        String name = new String(r.getString("name"));
     
        names.put(id, name);
    }
    ...
    names collection will contain all ids and names from Names table.
    Last edited by gaszabo; April 4th, 2012 at 06:00 AM.

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