From 06ecfd27c95f01445f1f2442efa3dca64d19e4be Mon Sep 17 00:00:00 2001
From: Henry Su <henrysu4707@gmail.com>
Date: Fri, 4 Sep 2026 13:28:31 -0500
Subject: [PATCH] fix: parse column checks with pg_get_expr instead of
 substring

NOT VALID and NO INHERIT suffixes made the old CHECK (...) length
heuristic return a corrupted expression into the columns API.
---
 src/lib/sql/columns.sql.ts | 18 +++++++++++++-----
 test/lib/columns.ts        | 35 +++++++++++++++++++++++++++++++++++
 2 files changed, 48 insertions(+), 5 deletions(-)

diff --git a/src/lib/sql/columns.sql.ts b/src/lib/sql/columns.sql.ts
index d4f6b6c72..91325cbee 100644
--- a/src/lib/sql/columns.sql.ts
+++ b/src/lib/sql/columns.sql.ts
@@ -98,11 +98,19 @@ FROM
     SELECT DISTINCT ON (table_id, ordinal_position)
       conrelid AS table_id,
       conkey[1] AS ordinal_position,
-      substring(
-        pg_get_constraintdef(pg_constraint.oid, true),
-        8,
-        length(pg_get_constraintdef(pg_constraint.oid, true)) - 8
-      ) AS "definition"
+      -- Prefer pg_get_expr over stripping CHECK (...) from pg_get_constraintdef:
+      -- suffixes like NOT VALID / NO INHERIT make the old length-8 heuristic corrupt
+      -- the expression (e.g. "id > 0) NOT VALI"). Strip one outer paren pair so the
+      -- API shape stays "c <> 0" rather than "(c <> 0)".
+      CASE
+        WHEN pg_get_expr(conbin, conrelid) LIKE '(%)' THEN
+          substring(
+            pg_get_expr(conbin, conrelid),
+            2,
+            length(pg_get_expr(conbin, conrelid)) - 2
+          )
+        ELSE pg_get_expr(conbin, conrelid)
+      END AS "definition"
     FROM pg_constraint
     WHERE contype = 'c' AND cardinality(conkey) = 1
     ORDER BY table_id, ordinal_position, oid asc
diff --git a/test/lib/columns.ts b/test/lib/columns.ts
index 3fcac79fe..92a4be8b1 100644
--- a/test/lib/columns.ts
+++ b/test/lib/columns.ts
@@ -981,6 +981,41 @@ test('dropping column checks', async () => {
   await pgMeta.query(`drop table t`)
 })
 
+test('column check with NOT VALID suffix', async () => {
+  await pgMeta.query(`
+    create table public.t (id int8);
+    alter table public.t add constraint t_id_check check (id > 0) not valid;
+  `)
+
+  const res = await pgMeta.columns.retrieve({
+    schema: 'public',
+    table: 't',
+    name: 'id',
+  })
+  expect(res.error).toBeNull()
+  // Must be the expression only — not `id > 0) NOT VALI` from the old substring heuristic
+  expect(res.data?.check).toBe('id > 0')
+
+  await pgMeta.query(`drop table public.t`)
+})
+
+test('column check with NO INHERIT suffix', async () => {
+  await pgMeta.query(`
+    create table public.t (id int8);
+    alter table public.t add constraint t_id_check check (id > 0) no inherit;
+  `)
+
+  const res = await pgMeta.columns.retrieve({
+    schema: 'public',
+    table: 't',
+    name: 'id',
+  })
+  expect(res.error).toBeNull()
+  expect(res.data?.check).toBe('id > 0')
+
+  await pgMeta.query(`drop table public.t`)
+})
+
 test('column with fully-qualified type', async () => {
   await pgMeta.query(`create table public.t(); create schema s; create type s.my_type as enum ();`)