From 8e62601a2e22e535e356cc768a07e99900f15f79 Mon Sep 17 00:00:00 2001
From: Pranav C <pranavxc@gmail.com>
Date: Fri, 12 Jul 2024 18:22:04 +0000
Subject: [PATCH] fix: show error while deleting column used in a custom
 relation

---
 packages/nocodb/src/db/BaseModelSqlv2.ts      |  2 +-
 .../nocodb/src/services/columns.service.ts    | 42 +++++++++++++++++++
 .../nocodb/src/services/tables.service.ts     |  2 +-
 3 files changed, 44 insertions(+), 2 deletions(-)

diff --git a/packages/nocodb/src/db/BaseModelSqlv2.ts b/packages/nocodb/src/db/BaseModelSqlv2.ts
index 8819059510..8effffb245 100644
--- a/packages/nocodb/src/db/BaseModelSqlv2.ts
+++ b/packages/nocodb/src/db/BaseModelSqlv2.ts
@@ -6936,7 +6936,7 @@ class BaseModelSqlv2 {
           delete item[key];
         }
       });
-    });k
+    });
 
     return data;
   }
diff --git a/packages/nocodb/src/services/columns.service.ts b/packages/nocodb/src/services/columns.service.ts
index 33f3028a6e..8cb5d1a8a0 100644
--- a/packages/nocodb/src/services/columns.service.ts
+++ b/packages/nocodb/src/services/columns.service.ts
@@ -64,6 +64,7 @@ import Noco from '~/Noco';
 import NcConnectionMgrv2 from '~/utils/common/NcConnectionMgrv2';
 import { MetaTable } from '~/utils/globals';
 import { MetaService } from '~/meta/meta.service';
+import { parseMetaProp } from '~/utils/modelUtils';
 
 // todo: move
 export enum Altered {
@@ -2099,6 +2100,47 @@ export class ColumnsService {
       ProjectMgrv2.getSqlMgr(context, { id: source.base_id }, ncMeta),
     );
 
+    // check column association with any custom links or LTAR
+    if (!isVirtualCol(col)) {
+      const links = await ncMeta.metaList2(
+        null,
+        null,
+        MetaTable.COL_RELATIONS,
+        {
+          xcCondition: {
+            _or: [
+              { fk_child_column_id: { eq: id } },
+              { fk_parent_column_id: { eq: id } },
+              { fk_mm_child_column_id: { eq: id } },
+              { fk_mm_parent_column_id: { eq: id } },
+            ],
+          },
+        },
+      );
+
+      // if custom relation then delete
+      if (
+        links?.length &&
+        links.every((lk) => {
+          try {
+            return parseMetaProp(lk)?.custom;
+          } catch {
+            // ignore
+          }
+        })
+      ) {
+        const linkCol = await Column.get(links[0].fk_column_id, ncMeta);
+        const table = await linkCol.getModel(ncMeta);
+        NcError.columnAssociatedWithLink(
+          `Column is associated with custom link ${
+            linkCol.title || linkCol.column_name
+          } (${
+            table.title || table.table_name
+          }). Please delete the link column first.`,
+        );
+      }
+    }
+
     /**
      * @Note: When using 'falls through to default' cases in a switch statement,
      * it is crucial to place them after cases with break statements.
diff --git a/packages/nocodb/src/services/tables.service.ts b/packages/nocodb/src/services/tables.service.ts
index 4e63db4f72..dbd4dfc8a7 100644
--- a/packages/nocodb/src/services/tables.service.ts
+++ b/packages/nocodb/src/services/tables.service.ts
@@ -238,7 +238,7 @@ export class TablesService {
         },
       );
 
-      if (relations.leghth) {
+      if (relations.length) {
         const relCol = await Column.get(relations[0].fk_column_id);
         const relTable = await Model.get(relCol.fk_model_id);
         NcError.badRequest(