diff --git a/sql/ccdi_bank_statement_add_project_id.sql b/sql/ccdi_bank_statement_add_project_id.sql
new file mode 100644
index 0000000..db42cfd
--- /dev/null
+++ b/sql/ccdi_bank_statement_add_project_id.sql
@@ -0,0 +1,14 @@
+-- 为 ccdi_bank_statement 表添加 project_id 字段
+-- 用途：关联项目ID，实现流水数据与项目的业务关联
+-- 作者：系统自动生成
+-- 日期：2026-03-04
+
+USE ccdi;
+
+-- 添加 project_id 字段
+ALTER TABLE `ccdi_bank_statement`
+ADD COLUMN `project_id` bigint(20) DEFAULT NULL COMMENT '关联项目ID' AFTER `bank_statement_id`;
+
+-- 添加索引以提升查询性能
+ALTER TABLE `ccdi_bank_statement`
+ADD INDEX `idx_project_id` (`project_id`);