fix: Make pfkSourceColumns query work with standard_conforming_strings = off

CHANGELOG.md

@@ -23,6 +23,7 @@ This project adheres to [Semantic Versioning](http://semver.org/).
  - #1871, Fix OpenAPI missing default values for String types and identify Array types as "array" instead of "string" - @laurenceisla
  - #1930, Fix RPC return type handling for `RETURNS TABLE` with a single column. Regression of #1615. - @wolfgangwalther
  - #1938, Fix using single double quotes(`"`) and backslashes(`/`) as values on the "in" operator - @steve-chavez
+ - #1992, Fix schema cache query failing with standard_conforming_strings = off - @wolfgangwalther
 
 ### Changed
 

src/PostgREST/DbStructure.hs

@@ -814,8 +814,8 @@ pfkSourceColumns cols =
                ','               , ''
             -- The same applies for `{` and `}`, although those are used a lot in pg_node_tree.
             -- We remove the escaped ones, which might be part of column names again.
-            ), '\{'              , ''
+            ), E'\\{'            , ''
-            ), '\}'              , ''
+            ), E'\\}'            , ''
             -- The fields we need are formatted as json manually to protect them from the regex.
             ), ' :targetList '   , ',"targetList":'
             ), ' :resno '        , ',"resno":'