hardingCore 版本7.8.1.22
var minTime = new DateTime(2024, 1, 1);
var maxTime = new DateTime(2028, 12, 31);
// 一次性Join查询:订单 + 用户
var query = from order in _dbContext.Orders
.Where(o => o.CreationTime >= minTime && o.CreationTime <= maxTime)
join user in _dbContext.Users
on order.UserId equals user.Id into userGroup
from user in userGroup.DefaultIfEmpty()
select new
{
order.Id,
order.UserId,
userName = user != null ? user.Name : "(未知)",
order.Money,
order.CreationTime
};
var result = await query.ToListAsync();
这Orders是按CreationTime按年分库,Users不分库是基础库,分步查询可以查出数据,合并查询查不出来
hardingCore 版本7.8.1.22
var minTime = new DateTime(2024, 1, 1);
var maxTime = new DateTime(2028, 12, 31);
// 一次性Join查询:订单 + 用户
var query = from order in _dbContext.Orders
.Where(o => o.CreationTime >= minTime && o.CreationTime <= maxTime)
join user in _dbContext.Users
on order.UserId equals user.Id into userGroup
from user in userGroup.DefaultIfEmpty()
select new
{
order.Id,
order.UserId,
userName = user != null ? user.Name : "(未知)",
order.Money,
order.CreationTime
};
var result = await query.ToListAsync();
这Orders是按CreationTime按年分库,Users不分库是基础库,分步查询可以查出数据,合并查询查不出来