bug: fix constraint on customer table to allow soft-deletes (#6631)

.changeset/eighty-eagles-reply.md

@@ -0,0 +1,5 @@
+---
+"@medusajs/medusa": patch
+---
+
+bug: fix constraint on customer table to allow soft-deletes

packages/medusa/src/migrations/1709888477798-alter-customer-unique-constraint.ts

@@ -0,0 +1,37 @@
+import { MigrationInterface, QueryRunner } from "typeorm"
+
+export class AlterCustomerUniqueConstraint1709888477798 implements MigrationInterface {
+  public async up(queryRunner: QueryRunner): Promise<void> {
+    await queryRunner.query(`
+      ALTER TABLE "customer" DROP CONSTRAINT "UQ_unique_email_for_guests_and_customer_accounts";
+
+      CREATE UNIQUE INDEX "IDX_unique_email_for_guests_and_customer_accounts" ON "customer" ("email", "has_account") WHERE "deleted_at" IS NULL;
+    `)
+  }
+
+  public async down(queryRunner: QueryRunner): Promise<void> {
+    // ensure we dont have duplicated email,has_account to avoid violation of the previous unique constraint
+    await queryRunner.query(`
+      WITH RankedCustomers AS (
+        SELECT
+          id,
+          ROW_NUMBER() OVER (
+            PARTITION BY email, has_account
+            ORDER BY CASE WHEN deleted_at IS NULL THEN 0 ELSE 1 END, id
+          ) AS rn
+        FROM
+          customer
+      )
+      DELETE FROM customer
+      WHERE id IN (
+        SELECT id FROM RankedCustomers WHERE rn > 1
+      );
+    `);
+
+    await queryRunner.query(`
+      DROP INDEX "IDX_unique_email_for_guests_and_customer_accounts";
+
+      ALTER TABLE "customer" ADD CONSTRAINT "UQ_unique_email_for_guests_and_customer_accounts" UNIQUE ("email", "has_account");
+    `)
+  }
+}

packages/medusa/src/models/customer.ts

@@ -19,7 +19,7 @@ import { SoftDeletableEntity } from "../interfaces/models/soft-deletable-entity"
 import { generateEntityId } from "../utils/generate-entity-id"
 
 @Entity()
-@Unique(["email", "has_account"])
+@Index(["email", "has_account"], { unique: true, where: "deleted_at IS NULL" })
 export class Customer extends SoftDeletableEntity {
   @Index()
   @Column()