Started to implement the database helper class

app/src/main/java/de/mobcomp/grades/database/DBHelper.java

@@ -0,0 +1,40 @@
+package de.mobcomp.grades.database;
+
+import android.content.ContentResolver;
+import android.content.Context;
+import android.net.Uri;
+
+/**
+ * Helper class to access the database with convenience methods.
+ */
+public class DBHelper {
+    private Context context;
+    private ContentResolver contentResolver;
+
+    private static final Uri UNIVERSITY_URI;
+    private static final Uri RULE_URI;
+    private static final Uri ACTION_URI;
+    private static final Uri ACTION_PARAM_URI;
+    private static final Uri TRANSFORMER_URI;
+    private static final Uri GRADE_ENTRY_URI;
+    private static final Uri OVERVIEW_URI;
+
+    static {
+        Uri contentUri = GradesProvider.CONTENT_URI;
+
+        UNIVERSITY_URI = contentUri.buildUpon().appendPath(Database.University.TABLE).build();
+        RULE_URI = contentUri.buildUpon().appendPath(Database.Rule.TABLE).build();
+        ACTION_URI = contentUri.buildUpon().appendPath(Database.Action.TABLE).build();
+        ACTION_PARAM_URI = contentUri.buildUpon().appendPath(Database.ActionParam.TABLE).build();
+        TRANSFORMER_URI = contentUri.buildUpon().appendPath(Database.Transformer.TABLE).build();
+        GRADE_ENTRY_URI = contentUri.buildUpon().appendPath(Database.GradeEntry.TABLE).build();
+        OVERVIEW_URI = contentUri.buildUpon().appendPath(Database.Overview.TABLE).build();
+    }
+
+    public DBHelper(Context context) {
+        this.context = context.getApplicationContext();
+        this.contentResolver = this.context.getContentResolver();
+    }
+
+    // TODO: implement convenience methods for database queries, inserts, etc...
+}