Fix sql semantics

Author: dmashuda

internal/dev_server/events_db/sqlite.go

@@ -154,7 +154,7 @@ func (s *Sqlite) QueryDebugSessions(ctx context.Context, limit int, offset int)
 
 	// Get total count for pagination info
 	var totalCount int64
-	countQuery := `SELECT COUNT(*) FROM debug_session`
+	countQuery := `SELECT count(DISTINCT(debug_session_key)) FROM debug_events`
 	err = s.database.QueryRowContext(ctx, countQuery).Scan(&totalCount)
 	if err != nil {
 		return nil, err

internal/dev_server/events_db/sqlite_test.go

@@ -45,6 +45,9 @@ func TestDBFunctions(t *testing.T) {
 	t.Run("WriteEvent succeeds", func(t *testing.T) {
 		err := store.WriteEvent(ctx, debugSessionKey, "summary", []byte(testEvent))
 		require.NoError(t, err)
+
+		err = store.WriteEvent(ctx, "another-session", "summary", []byte(testEvent))
+		require.NoError(t, err)
 	})
 
 	t.Run("QueryEvents with no filter", func(t *testing.T) {
@@ -110,7 +113,9 @@ func TestDBFunctions(t *testing.T) {
 		require.NoError(t, err)
 		err = store.WriteEvent(ctx, "session-2", "diagnostic", []byte(`{"kind":"diagnostic","data":"test"}`))
 		require.NoError(t, err)
-		// session-3 will have 0 events
+
+		err = store.WriteEvent(ctx, "session-3", "diagnostic", []byte(`{"kind":"diagnostic","data":"test"}`))
+		require.NoError(t, err)
 
 		// Query first page
 		page, err := store.QueryDebugSessions(ctx, 2, 0)
@@ -131,7 +136,7 @@ func TestDBFunctions(t *testing.T) {
 		allPage, err := store.QueryDebugSessions(ctx, 10, 0)
 		require.NoError(t, err)
 		require.NotNil(t, allPage)
-		require.Len(t, allPage.Sessions, 2)
+		require.Len(t, allPage.Sessions, 4)
 		require.Equal(t, int64(4), allPage.TotalCount)
 		require.False(t, allPage.HasMore)
 
@@ -141,9 +146,9 @@ func TestDBFunctions(t *testing.T) {
 			allSessionKeys[session.Key] = session.EventCount
 		}
 
-		require.Equal(t, int64(0), allSessionKeys["session-3"])
+		require.Equal(t, int64(1), allSessionKeys["session-3"])
 		require.Equal(t, int64(2), allSessionKeys["session-2"])
-		require.Equal(t, int64(0), allSessionKeys["another-session"])
+		require.Equal(t, int64(1), allSessionKeys["another-session"])
 		require.Equal(t, int64(4), allSessionKeys[debugSessionKey]) // 4 events from previous tests
 
 		// Test pagination - second page