Fix relative path mismatch (#151)

migration/relative_path_fix.10.cr

@@ -0,0 +1,31 @@
+# In DB version 8, we replaced the absolute paths in DB with relative paths,
+#   but we mistakenly left the starting slashes. This migration removes them.
+class RelativePathFix < MG::Base
+  def up : String
+    <<-SQL
+    -- remove leading slashes from the paths in ids
+    UPDATE ids
+    SET path = SUBSTR(path, 2, LENGTH(path) - 1)
+    WHERE path LIKE '/%';
+
+    -- remove leading slashes from the paths in titles
+    UPDATE titles
+    SET path = SUBSTR(path, 2, LENGTH(path) - 1)
+    WHERE path LIKE '/%';
+    SQL
+  end
+
+  def down : String
+    <<-SQL
+    -- add leading slashes to paths in ids
+    UPDATE ids
+    SET path = '/' || path
+    WHERE path NOT LIKE '/%';
+
+    -- add leading slashes to paths in titles
+    UPDATE titles
+    SET path = '/' || path
+    WHERE path NOT LIKE '/%';
+    SQL
+  end
+end