-- 手工派车日历拆成酸、碱两套独立数据。已有记录归入酸派车日历。 -- MySQL 5.7 / utf8mb4。可重复执行。 SET NAMES utf8mb4; SET @col_exists = ( SELECT COUNT(*) FROM information_schema.COLUMNS WHERE TABLE_SCHEMA = DATABASE() AND TABLE_NAME = 'pl_dispatch_calendar' AND COLUMN_NAME = 'calendar_kind' ); SET @ddl = IF( @col_exists = 0, 'ALTER TABLE `pl_dispatch_calendar` ADD COLUMN `calendar_kind` varchar(16) NOT NULL DEFAULT ''acid'' COMMENT ''日历类型:acid酸派车 alkali碱派车 other其他'' AFTER `destination`', 'SELECT 1' ); PREPARE stmt FROM @ddl; EXECUTE stmt; DEALLOCATE PREPARE stmt;