feat: implement aggregation methods with support for grouping and median calculations in Clickhouse, MongoDB, and MySQL connectors

Author: kulikp1

adminforth/dataConnectors/clickhouse.ts

@@ -449,7 +449,7 @@ class ClickhouseConnector extends AdminForthBaseConnector implements IAdminForth
       filters: IAdminForthAndOrFilter;
       aggregations: { [alias: string]: IAggregationRule };
       groupBy?: IGroupByRule;
-    }): Promise<Array<{ group?: string; [key: string]: any }>> {
+    }): Promise<any[]> {
 
       const tableName = `${this.dbName}.${resource.table}`;
 

adminforth/dataConnectors/mongo.ts

@@ -361,19 +361,15 @@ class MongoConnector extends AdminForthBaseConnector implements IAdminForthDataS
         pipeline.push({
             $project: {
                 _id: 0,
-                group: {
-                    $cond: {
-                        if: { $isNumber: "$_id" },
-                        then: "$_id",
-                        else: {
-                            $cond: {
-                                if: { $toString: "$_id" }, 
-                                then: { $dateToString: { format: "%Y-%m-%d", date: "$_id", timezone: groupBy?.timezone ?? 'UTC' } },
-                                else: "$_id"
-                            }
+                group: groupBy?.type === 'date_trunc'
+                    ? {
+                        $cond: {
+                            if: { $eq: [{ $type: "$_id" }, "date"] },
+                            then: { $dateToString: { format: "%Y-%m-%d", date: "$_id", timezone: groupBy?.timezone ?? 'UTC' } },
+                            else: "$_id"
                         }
                     }
-                },
+                    : "$_id",
                 ...Object.fromEntries(
                     Object.keys(groupStage)
                     .filter(k => k !== '_id')

adminforth/dataConnectors/mysql.ts

@@ -386,7 +386,7 @@ class MysqlConnector extends AdminForthBaseConnector implements IAdminForthDataS
         case 'min':   selectParts.push(`MIN(${f}) AS \`${alias}\``); break;
         case 'max':   selectParts.push(`MAX(${f}) AS \`${alias}\``); break;
         case 'median': 
-          selectParts.push(`GROUP_CONCAT(${f}) AS \`${alias}\``); 
+          selectParts.push(`GROUP_CONCAT(${f} ORDER BY ${f} ASC SEPARATOR ',') AS \`${alias}\``); 
           medianAliases.push(alias);
           break;
       }
@@ -396,7 +396,9 @@ class MysqlConnector extends AdminForthBaseConnector implements IAdminForthDataS
     let query = `SELECT ${selectParts.join(', ')} FROM \`${tableName}\` ${where}`;
     if (groupExpr) query += ` GROUP BY ${groupExpr} ORDER BY ${groupExpr} ASC`;
 
-    await this.client.execute("SET SESSION group_concat_max_len = 1000000;");
+    if (medianAliases.length > 0) {
+      await this.client.execute("SET SESSION group_concat_max_len = 1000000;");
+    }
 
     const [rows]: any = await this.client.execute(query, filterValues);