代码：

AppointmentModel::field(['identity'])->count('distinct identity')

生成的sql：

SELECT COUNT(DISTINCT `identity`) AS think_count FROM `dg_appointment`;

下面是tp6手册内容

我尝试着这样写 发现生成的sql不对

AppointmentModel::distinct(true)->field(['identity'])->count('identity')；

SELECT DISTINCT  COUNT(`identity`) AS think_count FROM `dg_appointment` ;