Refactor: Fix set_variable serialization and update tests

Co-authored-by: contact <[email protected]>

Author: cursoragent

examples/official-site/sqlpage/migrations/70_set_variable.sql renamed to examples/official-site/sqlpage/migrations/71_set_variable.sql

@@ -634,7 +634,7 @@ async fn set_variable<'a>(
     }
 
     let json_val = serde_json::Value::Object(params_map);
-    let encoded: URLParameters = serde_json::from_value(json_val)?;
+    let encoded: URLParameters = serde_json::from_str(&json_val.to_string())?;
 
     let mut url = context.path.clone();
     let encoded_str = encoded.get();

src/webserver/database/sqlpage_functions/functions.rs

@@ -1,7 +1,10 @@
 set url = sqlpage.set_variable('y', '2');
 set path = sqlpage.path();
+set x = json_extract(sqlpage.variables('get'), '$.x');
+
 select 'text' as component,
     case
-        when $url = $path || '?x=1&y=2' OR $url = $path || '?y=2&x=1' THEN 'It works !'
+        when $x is not null AND ($url = $path || '?x=' || $x || '&y=2' OR $url = $path || '?y=2&x=' || $x) THEN 'It works !'
+        when $x is null AND $url = $path || '?y=2' THEN 'It works !'
         else 'error: ' || $url
     end as contents;