codeasashu · May 27, 2016 20:16 · Feb 23, 2014
diff --git a/SimpleDatabaseHelper.java b/SimpleDatabaseHelper.java
@@ -0,0 +1,127 @@
+package se.mobileapplab.datademo;
+
+import android.content.ContentValues;
+import android.content.Context;
+import android.database.Cursor;
+import android.database.sqlite.SQLiteDatabase;
+import android.database.sqlite.SQLiteOpenHelper;
+
+/**
+ * Class that wraps the most common database operations. This example assumes you want a single table and data entity
+ * with two properties: a title and a priority as an integer. Modify in all relevant locations if you need other/more
+ * properties for your data and/or additional tables.
+ */
+public class SimpleDatabaseHelper {
+    private SQLiteOpenHelper _openHelper;
+
+    /**
+     * Construct a new database helper object
+     * @param context The current context for the application or activity
+     */
+    public SimpleDatabaseHelper(Context context) {
+        _openHelper = new SimpleSQLiteOpenHelper(context);
+    }
+
+    /**
+     * This is an internal class that handles the creation of all database tables
+     */
+    class SimpleSQLiteOpenHelper extends SQLiteOpenHelper {
+        SimpleSQLiteOpenHelper(Context context) {
+            super(context, "main.db", null, 1);
+        }
+
+        @Override
+        public void onCreate(SQLiteDatabase db) {
+            db.execSQL("create table todos (_id integer primary key autoincrement, title text, priority integer)");
+        }
+
+        @Override
+        public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
+        }
+    }
+
+    /**
+     * Return a cursor object with all rows in the table.
+     * @return A cursor suitable for use in a SimpleCursorAdapter
+     */
+    public Cursor getAll() {
+        SQLiteDatabase db = _openHelper.getReadableDatabase();
+        if (db == null) {
+            return null;
+        }
+        return db.rawQuery("select * from todos order by priority, title", null);
+    }
+
+    /**
+     * Return values for a single row with the specified id
+     * @param id The unique id for the row o fetch
+     * @return All column values are stored as properties in the ContentValues object
+     */
+    public ContentValues get(long id) {
+        SQLiteDatabase db = _openHelper.getReadableDatabase();
+        if (db == null) {
+            return null;
+        }
+        ContentValues row = new ContentValues();
+        Cursor cur = db.rawQuery("select title, priority from todos where _id = ?", new String[] { String.valueOf(id) });
+        if (cur.moveToNext()) {
+            row.put("title", cur.getString(0));
+            row.put("priority", cur.getInt(1));
+        }
+        cur.close();
+        db.close();
+        return row;
+    }
+
+    /**
+     * Add a new row to the database table
+     * @param title The title value for the new row
+     * @param priority The priority value for the new row
+     * @return The unique id of the newly added row
+     */
+    public long add(String title, int priority) {
+        SQLiteDatabase db = _openHelper.getWritableDatabase();
+        if (db == null) {
+            return 0;
+        }
+        ContentValues row = new ContentValues();
+        row.put("title", title);
+        row.put("priority", priority);
+        long id = db.insert("todos", null, row);
+        db.close();
+        return id;
+    }
+
+    /**
+     * Delete the specified row from the database table. For simplicity reasons, nothing happens if
+     * this operation fails.
+     * @param id The unique id for the row to delete
+     */
+    public void delete(long id) {
+        SQLiteDatabase db = _openHelper.getWritableDatabase();
+        if (db == null) {
+            return;
+        }
+        db.delete("todos", "_id = ?", new String[] { String.valueOf(id) });
+        db.close();
+    }
+
+    /**
+     * Updates a row in the database table with new column values, without changing the unique id of the row.
+     * For simplicity reasons, nothing happens if this operation fails.
+     * @param id The unique id of the row to update
+     * @param title The new title value
+     * @param priority The new priority value
+     */
+    public void update(long id, String title, int priority) {
+        SQLiteDatabase db = _openHelper.getWritableDatabase();
+        if (db == null) {
+            return;
+        }
+        ContentValues row = new ContentValues();
+        row.put("title", title);
+        row.put("priority", priority);
+        db.update("todos", row, "_id = ?", new String[] { String.valueOf(id) } );
+        db.close();
+    }
+}
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