From 11d5c930c02e995d77c629f54d459f40fab368a2 Mon Sep 17 00:00:00 2001
From: Pranav C <pranavxc@gmail.com>
Date: Thu, 16 Nov 2023 12:24:10 +0000
Subject: [PATCH] feat: lookup support - mm/hm lookup - WIP

---
 .../src/db/generateMMLookupSelectQuery.ts     | 108 ++++++++++--------
 1 file changed, 58 insertions(+), 50 deletions(-)

diff --git a/packages/nocodb/src/db/generateMMLookupSelectQuery.ts b/packages/nocodb/src/db/generateMMLookupSelectQuery.ts
index baf5a703ae..767ec5e6e9 100644
--- a/packages/nocodb/src/db/generateMMLookupSelectQuery.ts
+++ b/packages/nocodb/src/db/generateMMLookupSelectQuery.ts
@@ -11,18 +11,23 @@ import type {
 import formulaQueryBuilderv2 from '~/db/formulav2/formulaQueryBuilderv2';
 import genRollupSelectv2 from '~/db/genRollupSelectv2';
 import { NcError } from '~/helpers/catchError';
+import {getAliasGenerator} from "~/utils";
 
 export default async function generateBTLookupSelectQuery({
   column,
   baseModelSqlv2,
   alias,
   model,
+    getAlias = getAliasGenerator('__lk_slt_')
 }: {
   column: Column;
   baseModelSqlv2: BaseModelSqlv2;
   alias: string;
   model: Model;
+    getAlias: ReturnType<typeof getAliasGenerator>
 }): Promise<any> {
+
+
   const knex = baseModelSqlv2.dbDriver;
 
   const rootAlias = alias;
@@ -30,7 +35,7 @@ export default async function generateBTLookupSelectQuery({
   {
     let aliasCount = 0,
       selectQb;
-    const alias = `__nc_lk_${aliasCount++}`;
+    const alias = getAlias();
     const lookup = await column.getColOptions<LookupColumn>();
     {
       const relationCol = await lookup.getRelationColumn();
@@ -62,7 +67,7 @@ export default async function generateBTLookupSelectQuery({
     let lookupColumn = await lookup.getLookupColumn();
     let prevAlias = alias;
     while (lookupColumn.uidt === UITypes.Lookup) {
-      const nestedAlias = `__nc_lk_nested_${aliasCount++}`;
+      const nestedAlias = getAlias();
       const nestedLookup = await lookupColumn.getColOptions<LookupColumn>();
       const relationCol = await nestedLookup.getRelationColumn();
       const relation =
@@ -70,62 +75,65 @@ export default async function generateBTLookupSelectQuery({
 
       // if any of the relation in nested lookup is
       // not belongs to then throw error as we don't support
-      if (relation.type !== RelationTypes.BELONGS_TO) {
-        // NcError.badRequest('HasMany/ManyToMany lookup is not supported');
-      }
+      if (relation.type === RelationTypes.BELONGS_TO) {
 
-      const childColumn = await relation.getChildColumn();
-      const parentColumn = await relation.getParentColumn();
-      const childModel = await childColumn.getModel();
-      await childModel.getColumns();
-      const parentModel = await parentColumn.getModel();
-      await parentModel.getColumns();
+          const childColumn = await relation.getChildColumn();
+          const parentColumn = await relation.getParentColumn();
+          const childModel = await childColumn.getModel();
+          await childModel.getColumns();
+          const parentModel = await parentColumn.getModel();
+          await parentModel.getColumns();
 
-      selectQb.join(
-        `${baseModelSqlv2.getTnPath(parentModel.table_name)} as ${nestedAlias}`,
-        `${nestedAlias}.${parentColumn.column_name}`,
-        `${prevAlias}.${childColumn.column_name}`,
-      );
+          selectQb.join(
+              `${baseModelSqlv2.getTnPath(parentModel.table_name)} as ${nestedAlias}`,
+              `${nestedAlias}.${parentColumn.column_name}`,
+              `${prevAlias}.${childColumn.column_name}`,
+          );
 
+      } else     if (relation.type === RelationTypes.HAS_MANY) {
 
+      }else     if (relation.type === RelationTypes.MANY_TO_MANY) {
+ const mmTableAlias = getAlias()
 
+          const mmModel = await relation.getMMModel();
+          const mmChildCol = await relation.getMMChildColumn();
+          const mmParentCol = await relation.getMMParentColumn();
+
+          knex(
+              `${baseModelSqlv2.getTnPath(
+                  parentModel?.table_name,
+              )} as ${refTableAlias}`,
+          )
+              [columnOptions.rollup_function as string]?.(
+              knex.ref(`${refTableAlias}.${rollupColumn.column_name}`),
+          )
+              .innerJoin(
+                  baseModelSqlv2.getTnPath(mmModel.table_name),
+                  knex.ref(
+                      `${baseModelSqlv2.getTnPath(mmModel.table_name)}.${
+                          mmParentCol.column_name
+                      }`,
+                  ),
+                  '=',
+                  knex.ref(`${refTableAlias}.${parentCol.column_name}`),
+              )
+              .where(
+                  knex.ref(
+                      `${baseModelSqlv2.getTnPath(mmModel.table_name)}.${
+                          mmChildCol.column_name
+                      }`,
+                  ),
+                  '=',
+                  knex.ref(
+                      `${alias || baseModelSqlv2.getTnPath(childModel.table_name)}.${
+                          childCol.column_name
+                      }`,
+                  ),
+              )
+      }
 
 
-      const mmModel = await relationColumnOption.getMMModel();
-      const mmChildCol = await relationColumnOption.getMMChildColumn();
-      const mmParentCol = await relationColumnOption.getMMParentColumn();
 
-   knex(
-            `${baseModelSqlv2.getTnPath(
-                parentModel?.table_name,
-            )} as ${refTableAlias}`,
-        )
-            [columnOptions.rollup_function as string]?.(
-            knex.ref(`${refTableAlias}.${rollupColumn.column_name}`),
-        )
-            .innerJoin(
-                baseModelSqlv2.getTnPath(mmModel.table_name),
-                knex.ref(
-                    `${baseModelSqlv2.getTnPath(mmModel.table_name)}.${
-                        mmParentCol.column_name
-                    }`,
-                ),
-                '=',
-                knex.ref(`${refTableAlias}.${parentCol.column_name}`),
-            )
-            .where(
-                knex.ref(
-                    `${baseModelSqlv2.getTnPath(mmModel.table_name)}.${
-                        mmChildCol.column_name
-                    }`,
-                ),
-                '=',
-                knex.ref(
-                    `${alias || baseModelSqlv2.getTnPath(childModel.table_name)}.${
-                        childCol.column_name
-                    }`,
-                ),
-            )
 
       lookupColumn = await nestedLookup.getLookupColumn();
       prevAlias = nestedAlias;