From 1c2a8e62ca730ba1702143c6d78187e4c78dd2e4 Mon Sep 17 00:00:00 2001
From: Jussi Saurio <jussi.saurio@gmail.com>
Date: Mon, 3 Nov 2025 11:41:07 +0200
Subject: [PATCH] Fix: return error on provided insert column count mismatch

---
 core/translate/insert.rs | 20 ++++++++++++
 testing/insert.test      | 67 ++++++++++++++++++++++++++++++++++++++++
 2 files changed, 87 insertions(+)

diff --git a/core/translate/insert.rs b/core/translate/insert.rs
index b5b7b7519..c6c9e90a8 100644
--- a/core/translate/insert.rs
+++ b/core/translate/insert.rs
@@ -1059,6 +1059,20 @@ fn init_source_emission<'a>(
     body: InsertBody,
     columns: &'a [ast::Name],
 ) -> Result<ProgramBuilder> {
+    let required_column_count = if columns.is_empty() {
+        table.columns().len()
+    } else {
+        columns.len()
+    };
+    if !values.is_empty() {
+        // If we had a single tuple in VALUES, it was inserted into the values vector parameter.
+        if values.len() != required_column_count {
+            crate::bail_parse_error!(
+                "{} values for {required_column_count} columns",
+                values.len()
+            );
+        }
+    }
     let (num_values, cursor_id) = match body {
         InsertBody::Select(select, _) => {
             // Simple common case of INSERT INTO <table> VALUES (...) without compounds.
@@ -1088,6 +1102,12 @@ fn init_source_emission<'a>(
                 program.incr_nesting();
                 let result =
                     translate_select(select, resolver, program, query_destination, connection)?;
+                if result.num_result_cols != required_column_count {
+                    crate::bail_parse_error!(
+                        "{} values for {required_column_count} columns",
+                        result.num_result_cols,
+                    );
+                }
                 program = result.program;
                 program.decr_nesting();
 
diff --git a/testing/insert.test b/testing/insert.test
index 3eaa44bc0..e8c270aeb 100755
--- a/testing/insert.test
+++ b/testing/insert.test
@@ -798,3 +798,70 @@ do_execsql_test_on_specific_db {:memory:} ignore-intra-statement-dups {
     SELECT a,b FROM t ORDER BY a;
 } {5|first
 6|x}
+
+# Tests for incorrect provided column count
+
+do_execsql_test_in_memory_any_error wrong-column-count-values-too-few {
+    CREATE TABLE t(a, b, c);
+    INSERT INTO t VALUES (1, 2);
+}
+
+do_execsql_test_in_memory_any_error wrong-column-count-values-too-many {
+    CREATE TABLE t(a, b);
+    INSERT INTO t VALUES (1, 2, 3);
+}
+
+do_execsql_test_in_memory_any_error wrong-column-count-values-specified-columns-too-few {
+    CREATE TABLE t(a, b, c);
+    INSERT INTO t(a, b, c) VALUES (1, 2);
+}
+
+do_execsql_test_in_memory_any_error wrong-column-count-values-specified-columns-too-many {
+    CREATE TABLE t(a, b);
+    INSERT INTO t(a, b) VALUES (1, 2, 3);
+}
+
+do_execsql_test_in_memory_any_error wrong-column-count-select-named-too-few {
+    CREATE TABLE src(x, y);
+    INSERT INTO src VALUES (1, 2);
+    CREATE TABLE dst(a, b, c);
+    INSERT INTO dst SELECT x, y FROM src;
+}
+
+do_execsql_test_in_memory_any_error wrong-column-count-select-named-too-many {
+    CREATE TABLE src(x, y, z);
+    INSERT INTO src VALUES (1, 2, 3);
+    CREATE TABLE dst(a, b);
+    INSERT INTO dst SELECT x, y, z FROM src;
+}
+
+do_execsql_test_in_memory_any_error wrong-column-count-select-star-too-few {
+    CREATE TABLE src(x, y);
+    INSERT INTO src VALUES (1, 2);
+    CREATE TABLE dst(a, b, c);
+    INSERT INTO dst SELECT * FROM src;
+}
+
+do_execsql_test_in_memory_any_error wrong-column-count-select-star-too-many {
+    CREATE TABLE src(x, y, z);
+    INSERT INTO src VALUES (1, 2, 3);
+    CREATE TABLE dst(a, b);
+    INSERT INTO dst SELECT * FROM src;
+}
+
+do_execsql_test_in_memory_any_error wrong-column-count-specified-columns-select-mismatch {
+    CREATE TABLE src(x, y, z);
+    INSERT INTO src VALUES (1, 2, 3);
+    CREATE TABLE dst(a, b, c, d);
+    INSERT INTO dst(a, b) SELECT x, y, z FROM src;
+}
+
+do_execsql_test_in_memory_any_error wrong-column-count-partial-columns-values-too-few {
+    CREATE TABLE t(a, b, c);
+    INSERT INTO t(b, c) VALUES (2);
+}
+
+do_execsql_test_in_memory_any_error wrong-column-count-partial-columns-values-too-many {
+    CREATE TABLE t(a, b, c);
+    INSERT INTO t(a) VALUES (1, 2);
+}