Fix some MSSQL test cases.

packages/backend-core/src/sql/sql.ts

@@ -973,16 +973,18 @@ class InternalBuilder {
         subQuery = this.addJoinFieldCheck(subQuery, relationship)
       }
 
+      let wrapperQuery: Knex.QueryBuilder | Knex.Raw
       if (this.client === SqlClient.MS_SQL) {
-        subQuery = this.knex.raw(
-          `(SELECT a.* FROM (${subQuery}) AS a FOR JSON PATH)`
+        wrapperQuery = this.knex.raw(
+          `(SELECT [${toAlias}] = (SELECT a.* FROM (${subQuery}) AS a FOR JSON PATH))`
         )
-      }
-
+      } else {
         // @ts-ignore - the from alias syntax isn't in Knex typing
-      const wrapperQuery = this.knex.select(select).from({
+        wrapperQuery = this.knex.select(select).from({
           [toAlias]: subQuery,
         })
+      }
+
       query = query.select({ [relationship.column]: wrapperQuery })
     }
     return query