--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/pkg/imports/dsec.go	Wed Aug 07 13:11:16 2019 +0200
@@ -0,0 +1,116 @@
+// This is Free Software under GNU Affero General Public License v >= 3.0
+// without warranty, see README.md and license for details.
+//
+// SPDX-License-Identifier: AGPL-3.0-or-later
+// License-Filename: LICENSES/AGPL-3.0.txt
+//
+// Copyright (C) 2019 by via donau
+//   – Österreichische Wasserstraßen-Gesellschaft mbH
+// Software engineering by Intevation GmbH
+//
+// Author(s):
+//  * Sascha L. Teichmann <sascha.teichmann@intevation.de>
+
+package imports
+
+import (
+	"context"
+	"database/sql"
+	"fmt"
+)
+
+// DeleteSection is a Job to delete a section from the database.
+type DeleteSection struct {
+	ID int64 `json:"id"`
+}
+
+// DSECJobKind is the import queue type identifier.
+const DSECJobKind JobKind = "dsec"
+
+type dsecJobCreator struct{}
+
+func init() { RegisterJobCreator(DSECJobKind, dsecJobCreator{}) }
+
+func (dsecJobCreator) Description() string { return "delete section" }
+
+func (dsecJobCreator) AutoAccept() bool { return false }
+
+func (dsecJobCreator) Create() Job { return new(DeleteSection) }
+
+func (dsecJobCreator) Depends() [2][]string {
+	return [2][]string{
+		{"sections"},
+		{},
+	}
+}
+
+const (
+	dsecExistsSQL = `
+SELECT EXISTS (
+  SELECT 1 FROM waterway.sections
+  WHERE id = $1 AND staging_done)
+`
+	dsecStageDoneSQL = `
+DELETE FROM waterway.sections
+WHERE id IN (
+  SELECT key from import.track_imports
+  WHERE import_id = $1 AND
+        deletion AND
+        relation = 'waterway.sections'::regclass)`
+)
+
+// StageDone finally removes the section from the database.
+func (dsecJobCreator) StageDone(
+	ctx context.Context,
+	tx *sql.Tx,
+	id int64,
+) error {
+	_, err := tx.ExecContext(ctx, dsecStageDoneSQL, id)
+	return err
+}
+
+// CleanUp of a section delete import is a NOP.
+func (*DeleteSection) CleanUp() error { return nil }
+
+// Do prepares the deletion of the section.
+func (dsec *DeleteSection) Do(
+	ctx context.Context,
+	importID int64,
+	conn *sql.Conn,
+	feedback Feedback,
+) (interface{}, error) {
+
+	tx, err := conn.BeginTx(ctx, nil)
+	if err != nil {
+		return nil, err
+	}
+	defer tx.Rollback()
+
+	var found bool
+	if err := tx.QueryRowContext(ctx, dsecExistsSQL, dsec.ID).Scan(dsec.ID); err != nil {
+		return nil, err
+	}
+
+	if !found {
+		return nil, fmt.Errorf("no section witd id %d found", dsec.ID)
+	}
+
+	feedback.Info("Prepare deletion of section with id %d", dsec.ID)
+
+	if _, err := tx.ExecContext(
+		ctx,
+		trackImportDeletionSQL,
+		importID,
+		true,
+		"waterway.sections",
+		dsec.ID,
+	); err != nil {
+		return nil, err
+	}
+
+	if err := tx.Commit(); err != nil {
+		return nil, err
+	}
+
+	return dsec, nil
+}