1 files changed, 79 insertions, 0 deletions
diff --git a/db/migrate/20220106163326_add_has_issues_on_vulnerability_reads_trigger.rb b/db/migrate/20220106163326_add_has_issues_on_vulnerability_reads_trigger.rb
new file mode 100644
index 00000000000..b3023a1f915
--- /dev/null
+++ b/db/migrate/20220106163326_add_has_issues_on_vulnerability_reads_trigger.rb
@@ -0,0 +1,79 @@
+# frozen_string_literal: true
+
+class AddHasIssuesOnVulnerabilityReadsTrigger < Gitlab::Database::Migration[1.0]
+  include Gitlab::Database::SchemaHelpers
+
+  TRIGGER_ON_INSERT = 'trigger_update_has_issues_on_vulnerability_issue_links_update'
+  INSERT_FUNCTION_NAME = 'set_has_issues_on_vulnerability_reads'
+
+  TRIGGER_ON_DELETE = 'trigger_update_has_issues_on_vulnerability_issue_links_delete'
+  DELETE_FUNCTION_NAME = 'unset_has_issues_on_vulnerability_reads'
+
+  def up
+    create_trigger_function(INSERT_FUNCTION_NAME, replace: true) do
+      <<~SQL
+        UPDATE
+          vulnerability_reads
+        SET
+          has_issues = true
+        WHERE
+          vulnerability_id = NEW.vulnerability_id AND has_issues IS FALSE;
+        RETURN NULL;
+      SQL
+    end
+
+    execute(<<~SQL)
+      CREATE OR REPLACE FUNCTION #{DELETE_FUNCTION_NAME}()
+      RETURNS TRIGGER
+      LANGUAGE plpgsql
+      AS $$
+      DECLARE
+        has_issue_links integer;
+      BEGIN
+        PERFORM 1
+        FROM
+          vulnerability_reads
+        WHERE
+          vulnerability_id = OLD.vulnerability_id
+        FOR UPDATE;
+
+        SELECT 1 INTO has_issue_links FROM vulnerability_issue_links WHERE vulnerability_id = OLD.vulnerability_id LIMIT 1;
+
+        IF (has_issue_links = 1) THEN
+          RETURN NULL;
+        END IF;
+
+        UPDATE
+          vulnerability_reads
+        SET
+          has_issues = false
+        WHERE
+          vulnerability_id = OLD.vulnerability_id;
+
+        RETURN NULL;
+      END
+      $$;
+    SQL
+
+    execute(<<~SQL)
+      CREATE TRIGGER #{TRIGGER_ON_INSERT}
+      AFTER INSERT ON vulnerability_issue_links
+      FOR EACH ROW
+      EXECUTE FUNCTION #{INSERT_FUNCTION_NAME}();
+    SQL
+
+    execute(<<~SQL)
+      CREATE TRIGGER #{TRIGGER_ON_DELETE}
+      AFTER DELETE ON vulnerability_issue_links
+      FOR EACH ROW
+      EXECUTE FUNCTION #{DELETE_FUNCTION_NAME}();
+    SQL
+  end
+
+  def down
+    drop_trigger(:vulnerability_issue_links, TRIGGER_ON_INSERT)
+    drop_function(INSERT_FUNCTION_NAME)
+    drop_trigger(:vulnerability_issue_links, TRIGGER_ON_DELETE)
+    drop_function(DELETE_FUNCTION_NAME)
+  end
+end