Updates

dist/types/index.d.ts

@@ -643,7 +643,6 @@ export type ServerQueryParam<T extends {
     /**
      * Raw SQL to use as select
      */
-    select_sql?: string;
     [key: string]: any;
 };
 /**
@@ -808,7 +807,17 @@ export type ServerQueryParamsJoin<Table extends string = string, Field extends o
     /**
      * Raw SQL to use as join select
      */
-    select_sql?: string;
+    /**
+     * Concatenate multiple matches from another table
+     */
+    group_concat?: {
+        field: string;
+        alias: string;
+        /**
+         * Separator. Default `,`
+         */
+        separator?: string;
+    };
 };
 /**
  * Defines how a root-table field maps to a join-table field in an `ON` clause.

dist/utils/sql-generator.js

@@ -215,8 +215,9 @@ export default function sqlGenerator({ tableName, genObject, dbFullName, count }
                         if (existingJoinTableNames.includes(joinTableName))
                             return null;
                         existingJoinTableNames.push(joinTableName);
-                        if (joinObj.select_sql) {
-                            return joinObj.select_sql;
+                        if (joinObj.group_concat) {
+                            let group_concat = `GROUP_CONCAT(${joinTableName}.${joinObj.group_concat.field}, ${joinObj.group_concat.separator || ","}) AS ${joinObj.group_concat.alias}`;
+                            return group_concat;
                         }
                         else if (joinObj.selectFields) {
                             return joinObj.selectFields