diff --git a/.github/workflows/generate.yaml b/.github/workflows/generate.yaml
new file mode 100644
index 0000000..fd56fd3
--- /dev/null
+++ b/.github/workflows/generate.yaml
@@ -0,0 +1,40 @@
+name: generate
+
+on:
+  schedule:
+    - cron:  '0 0 * * *'
+  workflow_dispatch:
+
+jobs:
+  run:
+    runs-on: ubuntu-latest
+
+    steps:
+      - name: Setup PHP
+        uses: shivammathur/setup-php@v2
+        with:
+          php-version: '8.0'
+
+      - name: Checkout
+        uses: actions/checkout@v2
+
+      - name: Generate
+        run: make
+
+      - name: Count changes
+        id: changes
+        run: |
+          git add -N .
+          echo "::set-output name=count::$(git diff --name-only | wc -l)"
+
+      - name: Create Pull Request
+        uses: peter-evans/create-pull-request@v3
+        with:
+          commit-message: Update Error Code
+          delete-branch: true
+          title: Update Error Code
+          body: |
+            Error codes have been updated.
+
+            - https://github.com/postgres/postgres/blob/master/src/backend/utils/errcodes.txt
+        if: ${{ steps.changes.outputs.count > 0 }}
diff --git a/tools/generator.php b/tools/generator.php
index f61dd7c..db1ad2e 100644
--- a/tools/generator.php
+++ b/tools/generator.php
@@ -4,7 +4,10 @@
 $const = array();
 
 while ($row = fgets(STDIN)) {
-    if (preg_match('/^([0-9A-Z]{5}) +[SWE] +[^ ]+? +([a-z_]+)$/', $row, $matches)) {
+    if (preg_match('/^Section: (Class .*)$/', $row, $matches)) {
+        $const[] = '';
+        $const[] = "    // {$matches[1]}";
+    } elseif (preg_match('/^([0-9A-Z]{5}) +[SWE] +[^ ]+? +([a-z_]+)$/', $row, $matches)) {
         $key = strtoupper($matches[2]);
         if (isset($codes[$key])) {
             $key .= '_EXCEPTION';
@@ -14,7 +17,7 @@
     }
 }
 
-$const = implode(PHP_EOL, $const);
+$const = trim(implode(PHP_EOL, $const), PHP_EOL);
 
 echo <<<EOD
 <?php