Fix PostgreSQL test errors: union operations and JSON field access

.gitignore

@@ -12,3 +12,5 @@
 *.db
 tags
 .racoco
+zef/
+*.sqlite3

lib/Red/Driver/Pg.rakumod

@@ -47,8 +47,8 @@ submethod TWEAK() {
     ;
 }
 
-# JSON values are stringified when binding/reading
-method stringify-json { True }
+# JSON values are passed as native structures to DBIish  
+method stringify-json { False }
 
 method new-connection($dbh = $!dbh) { self.clone: dbh => $dbh }
 
@@ -148,13 +148,13 @@ multi method pg-jsonb-path-item(Str $_) { $_ }
 multi method translate(Red::AST::JsonItem $_, $context?) {
     my ($left, @lb) := do given self.translate: .left, $context { .key, .value };
     my $path = self.pg-jsonb-path-item: .right.value;
-    "($left #> '{ $path }')" => @lb
+    "($left #> '\{$path\}')" => @lb
 }
 
 multi method translate(Red::AST::JsonRemoveItem $_, $context?) {
     my ($left, @lb) := do given self.translate: .left, $context { .key, .value };
     my $path = self.pg-jsonb-path-item: .right.value;
-    "($left #- '{ $path }')" => @lb
+    "($left #- '\{$path\}')" => @lb
 }
 
 multi method translate(Red::AST::Value $_ where { .type ~~ Pair and .value.key ~~ Red::AST::JsonItem }, "update") {

lib/Red/Type/Json.rakumod

@@ -18,7 +18,7 @@ method deflator {
   -> $data {
     # TODO: Find a better way of doing this
     do if get-RED-DB.?stringify-json  {
-      try { to-json $data } // $data
+      try { to-json $data, :!pretty } // $data
     } else {
       $data
     }

t/14-union.rakutest

@@ -39,7 +39,6 @@ isa-ok $intersect2, M::ResultSeq;
 isa-ok $intersect2.ast, Red::AST::Intersect;
 is-deeply $intersect2.map(*.a).Seq.sort, eager 10 ^..^ 20;
 
-skip-rest("Pg do not accept minus"), exit with %*ENV<RED_DATABASE>;
 my $minus1 = M.^all (-) M.^all.grep(*.a >= 20);
 isa-ok $minus1, M::ResultSeq;
 isa-ok $minus1.ast, Red::AST::Minus;