From 67d320960d940b3164d94cfd57717cb5afbdf236 Mon Sep 17 00:00:00 2001
From: Jussi Saurio <jussi.saurio@gmail.com>
Date: Sat, 27 Sep 2025 09:37:15 +0300
Subject: [PATCH] ALTER TABLE: prevent dropping/renaming column referenced in
 VIEW

---
 core/vdbe/execute.rs | 45 ++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 45 insertions(+)

diff --git a/core/vdbe/execute.rs b/core/vdbe/execute.rs
index 4cc61a4f6..de826ebd1 100644
--- a/core/vdbe/execute.rs
+++ b/core/vdbe/execute.rs
@@ -7929,6 +7929,16 @@ pub fn op_drop_column(
         }
     }
 
+    for (view_name, view) in schema.views.iter() {
+        let view_select_sql = format!("SELECT * FROM {view_name}");
+        conn.prepare(view_select_sql.as_str()).map_err(|e| {
+            LimboError::ParseError(format!(
+                "cannot drop column \"{}\": referenced in VIEW {view_name}: {}",
+                column_name, view.sql,
+            ))
+        })?;
+    }
+
     state.pc += 1;
     Ok(InsnFunctionStepResult::Step)
 }
@@ -7984,6 +7994,20 @@ pub fn op_alter_column(
     let conn = program.connection.clone();
 
     let normalized_table_name = normalize_ident(table_name.as_str());
+    let old_column_name = {
+        let schema = conn.schema.read();
+        let table = schema
+            .tables
+            .get(table_name)
+            .expect("table being ALTERed should be in schema");
+        table
+            .get_column_at(*column_index)
+            .expect("column being ALTERed should be in schema")
+            .name
+            .as_ref()
+            .expect("column being ALTERed should be named")
+            .clone()
+    };
     let new_column = crate::schema::Column::from(definition);
 
     conn.with_schema_mut(|schema| {
@@ -8025,6 +8049,27 @@ pub fn op_alter_column(
         }
     });
 
+    let schema = conn.schema.read();
+    if *rename {
+        let table = schema
+            .tables
+            .get(&normalized_table_name)
+            .expect("table being ALTERed should be in schema");
+        let column = table
+            .get_column_at(*column_index)
+            .expect("column being ALTERed should be in schema");
+        for (view_name, view) in schema.views.iter() {
+            let view_select_sql = format!("SELECT * FROM {view_name}");
+            // FIXME: this should rewrite the view to reference the new column name
+            conn.prepare(view_select_sql.as_str()).map_err(|e| {
+                LimboError::ParseError(format!(
+                    "cannot rename column \"{}\": referenced in VIEW {view_name}: {}",
+                    old_column_name, view.sql,
+                ))
+            })?;
+        }
+    }
+
     state.pc += 1;
     Ok(InsnFunctionStepResult::Step)
 }