From c7ffea6a760f85c5c782f0d1735e6ce23847b9e3 Mon Sep 17 00:00:00 2001
From: Julius de Bruijn <julius+github@nauk.io>
Date: Mon, 2 Aug 2021 17:41:40 +0200
Subject: [PATCH] SQL Server: @unique should be allowed on @id

---
 .../tests/tables/mod.rs                       | 28 +++++++++++++++++++
 .../src/transform/ast_to_dml/db/attributes.rs | 17 ++---------
 .../core/tests/attributes/id_negative.rs      | 22 ---------------
 .../tests/migrations/unique.rs                | 14 ++++++++++
 4 files changed, 45 insertions(+), 36 deletions(-)

diff --git a/introspection-engine/introspection-engine-tests/tests/tables/mod.rs b/introspection-engine/introspection-engine-tests/tests/tables/mod.rs
index a68340ef1c49..640a89cfe050 100644
--- a/introspection-engine/introspection-engine-tests/tests/tables/mod.rs
+++ b/introspection-engine/introspection-engine-tests/tests/tables/mod.rs
@@ -815,6 +815,34 @@ async fn unique_and_index_on_same_field_works_sqlite(api: &TestApi) -> TestResul
     Ok(())
 }
 
+#[test_connector(tags(Mssql))]
+async fn unique_and_id_on_same_field_works_mssql(api: &TestApi) -> TestResult {
+    let schema = api.schema_name();
+
+    api.barrel()
+        .execute(|migration| {
+            migration.inject_custom(format!(
+                "create table {}.users (
+                       id int identity primary key,
+                       constraint unique_and_index_same unique(id) 
+                     );",
+                schema
+            ))
+        })
+        .await?;
+
+    let dm = indoc! {r##"
+        model users {
+          id Int @id @unique @default(autoincrement())
+        }
+    "##};
+
+    let result = &api.introspect().await?;
+    api.assert_eq_datamodels(dm, result);
+
+    Ok(())
+}
+
 #[test_connector(tags(Postgres))]
 // If multiple constraints are created in the create table statement Postgres seems to collapse them
 // into the first named one. So on the db level there will be one named really_must_be_different that
diff --git a/libs/datamodel/core/src/transform/ast_to_dml/db/attributes.rs b/libs/datamodel/core/src/transform/ast_to_dml/db/attributes.rs
index 597e41e9df29..f31765f86801 100644
--- a/libs/datamodel/core/src/transform/ast_to_dml/db/attributes.rs
+++ b/libs/datamodel/core/src/transform/ast_to_dml/db/attributes.rs
@@ -248,19 +248,8 @@ fn visit_scalar_field_attributes<'ast>(
             });
         }
 
-         // @unique
-         attributes.visit_optional_single("unique", ctx, |args, ctx| {
-             if let Some(source) = &ctx.db.datasource{
-                if source.active_provider == "sqlserver" {
-                    if let Some(pk) = &model_data.primary_key{
-                        if pk.source_field == Some(field_id) {
-                            ctx.push_error(args.new_attribute_validation_error(
-                         "SQLServer only allows either a unique or a primary key constraint on a column.", ))
-                        }
-                    }
-                }
-             }
-
+        // @unique
+        attributes.visit_optional_single("unique", ctx, |args, _ctx| {
             model_data.indexes.push((args.attribute(), IndexData {
                 is_unique: true,
                 fields: vec![field_id],
@@ -268,7 +257,7 @@ fn visit_scalar_field_attributes<'ast>(
                 name: None,
                 db_name: None,
             }))
-         });
+        });
     });
 }
 
diff --git a/libs/datamodel/core/tests/attributes/id_negative.rs b/libs/datamodel/core/tests/attributes/id_negative.rs
index bb807e0cadfd..eb413843ce03 100644
--- a/libs/datamodel/core/tests/attributes/id_negative.rs
+++ b/libs/datamodel/core/tests/attributes/id_negative.rs
@@ -158,25 +158,3 @@ fn relation_field_as_id_must_error() {
         Span::new(84, 86),
     ));
 }
-
-#[test]
-fn unique_should_error_if_unique_and_id_are_specified_on_sqlserver() {
-    let dml = r#"
-    datasource test {
-         provider = "sqlserver"
-         url = "sqlserver://...."
-    }
-    
-     model Model {
-         id Int @id @unique
-     }
-     "#;
-
-    let errors = parse_error(dml);
-
-    errors.assert_is(DatamodelError::new_attribute_validation_error(
-        "SQLServer only allows either a unique or a primary key constraint on a column.",
-        "unique",
-        Span::new(140, 146),
-    ));
-}
diff --git a/migration-engine/migration-engine-tests/tests/migrations/unique.rs b/migration-engine/migration-engine-tests/tests/migrations/unique.rs
index af035722073e..3c7f1d1ade12 100644
--- a/migration-engine/migration-engine-tests/tests/migrations/unique.rs
+++ b/migration-engine/migration-engine-tests/tests/migrations/unique.rs
@@ -157,3 +157,17 @@ fn removing_unique_from_an_existing_field_must_work(api: TestApi) {
     api.schema_push(dm2).send().assert_green_bang();
     api.assert_schema().assert_table("A", |t| t.assert_indexes_count(0));
 }
+
+#[test_connector]
+fn unique_is_allowed_on_an_id_field(api: TestApi) {
+    let dm1 = r#"
+        model A {
+            id    Int    @id @unique
+        }
+    "#;
+
+    api.schema_push(dm1).send().assert_green_bang();
+    api.assert_schema().assert_table("A", |t| {
+        t.assert_index_on_columns(&["id"], |idx| idx.assert_is_unique())
+    });
+}