-- =============================================================================
-- 将入学年份为 2026 或年级为 2026 的学生「是否住校」统一改为「是」
--
-- 目标表字段：
--   xg_student_msg.is_boarder  0-否，1-是
--   xg_student_msg.enrollment_year / grade
--   同时兼容班级表 xg_class_msg.enrollment_year / grade（学生字段为空时以班级为准）
--
-- 用法：
--   mysql -h <host> -u root -p hzdyjs_xg < docs/数据库脚本/2026-10-16-xg_student_msg-set-boarder-2026.sql
--
-- 建议：先执行「一、预览」确认影响范围，再执行「二、更新」
-- =============================================================================

SET NAMES utf8mb4;

-- -----------------------------------------------------------------------------
-- 一、预览：命中范围与当前住校分布
-- -----------------------------------------------------------------------------

SELECT '========== 1. 命中学生数量（含已是住校）==========' AS section;

SELECT COUNT(*) AS match_total
FROM xg_student_msg s
LEFT JOIN xg_class_msg c
  ON c.deleted = 0
 AND NULLIF(TRIM(s.class_id), '') IS NOT NULL
 AND c.id = CAST(NULLIF(TRIM(s.class_id), '') AS UNSIGNED)
WHERE s.deleted = 0
  AND (
       s.enrollment_year = 2026
    OR s.grade = '2026'
    OR c.enrollment_year = 2026
    OR c.grade = '2026'
  );

SELECT '========== 2. 命中且尚未住校（将被更新）==========' AS section;

SELECT COUNT(*) AS need_update_count
FROM xg_student_msg s
LEFT JOIN xg_class_msg c
  ON c.deleted = 0
 AND NULLIF(TRIM(s.class_id), '') IS NOT NULL
 AND c.id = CAST(NULLIF(TRIM(s.class_id), '') AS UNSIGNED)
WHERE s.deleted = 0
  AND IFNULL(s.is_boarder, 0) <> 1
  AND (
       s.enrollment_year = 2026
    OR s.grade = '2026'
    OR c.enrollment_year = 2026
    OR c.grade = '2026'
  );

SELECT '========== 3. 命中明细（抽样核对）==========' AS section;

SELECT
    s.id,
    s.student_no,
    s.name,
    s.enrollment_year AS student_enrollment_year,
    s.grade           AS student_grade,
    c.enrollment_year AS class_enrollment_year,
    c.grade           AS class_grade,
    s.is_boarder,
    s.class_name,
    s.college_name,
    s.student_status
FROM xg_student_msg s
LEFT JOIN xg_class_msg c
  ON c.deleted = 0
 AND NULLIF(TRIM(s.class_id), '') IS NOT NULL
 AND c.id = CAST(NULLIF(TRIM(s.class_id), '') AS UNSIGNED)
WHERE s.deleted = 0
  AND (
       s.enrollment_year = 2026
    OR s.grade = '2026'
    OR c.enrollment_year = 2026
    OR c.grade = '2026'
  )
ORDER BY s.enrollment_year, s.student_no
LIMIT 200;

-- -----------------------------------------------------------------------------
-- 二、更新：是否住校 -> 是(1)
-- -----------------------------------------------------------------------------

START TRANSACTION;

UPDATE xg_student_msg s
LEFT JOIN xg_class_msg c
  ON c.deleted = 0
 AND NULLIF(TRIM(s.class_id), '') IS NOT NULL
 AND c.id = CAST(NULLIF(TRIM(s.class_id), '') AS UNSIGNED)
SET
    s.is_boarder = 1,
    s.update_time = NOW()
WHERE s.deleted = 0
  AND IFNULL(s.is_boarder, 0) <> 1
  AND (
       s.enrollment_year = 2026
    OR s.grade = '2026'
    OR c.enrollment_year = 2026
    OR c.grade = '2026'
  );

-- 核对更新结果（事务内）
SELECT ROW_COUNT() AS updated_rows;

SELECT COUNT(*) AS still_not_boarder
FROM xg_student_msg s
LEFT JOIN xg_class_msg c
  ON c.deleted = 0
 AND NULLIF(TRIM(s.class_id), '') IS NOT NULL
 AND c.id = CAST(NULLIF(TRIM(s.class_id), '') AS UNSIGNED)
WHERE s.deleted = 0
  AND IFNULL(s.is_boarder, 0) <> 1
  AND (
       s.enrollment_year = 2026
    OR s.grade = '2026'
    OR c.enrollment_year = 2026
    OR c.grade = '2026'
  );

COMMIT;

-- 可选：仅预览不更新时，把上面 TRANSACTION 整段注释掉，或改为 ROLLBACK