Databases
StackOverflow2013
Postsdbo
PO
 

Note that there are some explanatory texts on larger screens.

plurals
  1. PO
    primarykey
    data
    text
    <p>The way I do is to have a class per table, named after the table with "Table" suffix (e.g. <code>PlayerTable</code> or <code>EventTable</code>).</p> <p>These classes contain all the static variable for the table name and all the field names, and they also contain two static methods:</p> <pre><code>public static void onCreate(SQLiteDatabase database) public static void onUpgrade(SQLiteDatabase database, int oldVersion, int newVersion) </code></pre> <p>So that my <code>SQLiteOpenHelper</code> can just call all of them, without having hundreds of static variables with all the fields and create queries. E.g:</p> <pre><code>@Override public void onCreate(SQLiteDatabase database) { PlayerTable.onCreate(database); EventTables.onCreate(database); ..... any other table you have ..... } </code></pre> <p>This class is then injected into all my data access objects (select / update / insert queries). For them I have dedicated classes that contain all my methods, by functionality (e.g. <code>EventHandlingDAO</code> for all the queries that deal with event handling).</p> <p>And finally, theses DAO are injected into the activities that need them, when needed.</p> <p><strong>EDIT:</strong> A few more details about my code:</p> <p>My main objects are the DAO (data access objects), in which I have methods like:</p> <pre><code>// in EventHandlingDAO: public void addEvent(Event event) { SQLiteDatabase database = databaseHelper.getWritableDatabase(); try { database.execSQL("INSERT INTO " + EventTable.EVENT_TABLE_NAME + " (...."); // list of fields and values } finally { database.close(); } } public List&lt;Event&gt; getAllEvents() { final List&lt;Event&gt; result = new ArrayList&lt;Event&gt;(); SQLiteDatabase database = databaseHelper.getReadableDatabase(); try { final Cursor cursor = database.rawQuery("SELECT " + EventTable.KEY_NAME + ", " + EventTable.KEY_DATE_AS_STRING + " FROM " + EventTable.TABLE_NAME, null); cursor.moveToFirst(); // ... rest of the logic, that iterates over the cursor, creates Event objects from the cursor columns and add them to the result list return result; } finally { database.close(); } } </code></pre> <p>So in that DAO, I have my databaseHelper object, which instanciates my class that extends <code>SQLiteOpenHelper</code> with the methods I talked about above.</p> <p>And of course, I have interfaces to all my DAO, so that I can inject a Stub or mocked implementation in my tests (or experiment with different implementations if I want to try another solution based on <code>SharedPreference</code> for example)</p> <p>And the code for my <code>PlayerTable</code> table:</p> <pre><code>public static void onCreate(SQLiteDatabase database) { database.execSQL(TABLE_CREATE); // TABLE_CREATE is my "CREATE TABLE..." query } public static void onUpgrade(SQLiteDatabase database, int oldVersion, int newVersion) { // A bit blunt, that destroys the data unfortunately, I'll think about doing something more clever later ;) database.execSQL("DROP TABLE IF EXISTS " + TABLE_NAME); onCreate(database); } </code></pre>
    singulars
    1. This table or related slice is empty.
    1. POStoring application database schema
      singulars
      1. PTQuestion
    1. PTAnswer
    1. USGuillaume
    1. USGuillaume
    plurals
    1. This table or related slice is empty.
    1. This table or related slice is empty.
    1. This table or related slice is empty.
    1. This table or related slice is empty.
    1. VO
      singulars
      1. PO
      1. This table or related slice is empty.
      1. VTUpMod
    1. CODo you have any public code to share with your database code management?
      singulars
      1. PO
      1. USdrupality
    2. COnot yet, sorry :) But the principles are basically the ones I stated above. More details: I can add more details in the answer, if you're interested in anything specific.
      singulars
      1. PO
      1. USGuillaume
    3. COCould you show me PlayerTable code and maybe a DAO class that uses PlayerTable?
      singulars
      1. PO
      1. USdrupality
 

Querying!

 
Guidance
A row detail

Detail views are divided into sections. All the information in the data section comes from columns in the selected row. The other sections display data from other, related rows.

Related data can be related in a to-one or a to-many fashion. Captions of data related in a to-many fashion link to a list view showing a filtered view of the table.

Try moving around until you find a non-empty to-many entry and click on the label to get to one. You can move back to the root by clicking on the database name in the header.

SQuiL has stopped working due to an internal error.

If you are curious you may find further information in the browser console, which is accessible through the devtools (F12).

Reload