c# - EF 生成的查询应为 "("

Question

以下代码是在 MySQL Server 5.7 上运行的 SQL 查询:

SELECT
  `t`.`c`,
  `t`.`Id`,
  `t0`.`Id`,
  `t0`.`Bio`,
  `t0`.`Image`,
  `t0`.`Name`,
  `t0`.`Follower_id`,
  `t0`.`Followed_id`
FROM
  (
    SELECT
      (
        SELECT
          COUNT(*)
        FROM
          `PROFILE_FOLLOW_PROFILE` AS `p`
        WHERE
          `u`.`Id` = `p`.`Followed_id`
      ) AS `c`,
      `u`.`Id`
    FROM
      `USER_PROFILES` AS `u`
    WHERE
      `u`.`Id` = 2
    LIMIT
      1
  ) AS `t`
  LEFT JOIN LATERAL (
    SELECT
      `u0`.`Id`,
      `u0`.`Bio`,
      `u0`.`Image`,
      `u0`.`Name`,
      `p0`.`Follower_id`,
      `p0`.`Followed_id`
    FROM
      `PROFILE_FOLLOW_PROFILE` AS `p0`
      INNER JOIN `USER_PROFILES` AS `u0` ON `p0`.`Follower_id` = `u0`.`Id`
    WHERE
      `t`.`Id` = `p0`.`Followed_id`
    ORDER BY
      (
        SELECT
          1
      )
    LIMIT
      10 OFFSET 0
  ) AS `t0` ON TRUE
ORDER BY
  `t`.`Id`,
  `t0`.`Follower_id`,
  `t0`.`Followed_id`,
  `t0`.`Id`

此查询将不会运行并将返回以下错误:

Error Code: 1064. You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near '(     SELECT       `u0`.`Id`,       `u0`.`Bio`,       `u0`.`Image`,       `u0`.`' at line 29

此语句是根据以下 EF 查询生成的:

        var selectedProfiles = _context.USER_PROFILES
                                    .Where(x => x.Id == id)
                                    .Select(x => new PagedListResult<ProfileForPostDto>
                                    {
                                        Total = x.Followers.Count,
                                        Data = (x.Followers
                                            .Select(f => new ProfileForPostDto
                                            {
                                                Id = f.Follower.Id,
                                                Bio = f.Follower.Bio,
                                                Image = f.Follower.Image,
                                                Name = f.Follower.Name
                                            })
                                            .Skip((pageNum - 1) * pageSize)
                                            .Take(pageSize)
                                            .ToList()),
                                        Page = pageNum,
                                        PageSize = pageSize
                                    }).FirstOrDefault();

我一直在检查 sql 查询的语法，根据我自己和 SQL 验证器的说法，它似乎是正确的。

程序上的日志指向语句的同一部分:

2020-03-02 20:06:44.239 +01:00 [Error] Failed executing DbCommand ("9"ms) [Parameters=["@__id_0='?' (DbType = Int32), @__pageSize_3='?' (DbType = Int32), @__p_2='?' (DbType = Int32)"], CommandType='Text', CommandTimeout='30']"
""SELECT `t`.`Id`, `t1`.`Id`, `t1`.`Bio`, `t1`.`Image`, `t1`.`Name`, `t1`.`Type`, `t1`.`User`, `t1`.`Follower_id`, `t1`.`Followed_id`
FROM (
    SELECT `u`.`Id`
    FROM `USER_PROFILES` AS `u`
    WHERE `u`.`Id` = @__id_0
    LIMIT 1
) AS `t`
LEFT JOIN LATERAL (
    SELECT `u0`.`Id`, `u0`.`Bio`, `u0`.`Image`, `u0`.`Name`, `u0`.`Type`, `u0`.`User`, `t`.`Follower_id`, `t`.`Followed_id`
    FROM (
        SELECT `p`.`Follower_id`, `p`.`Followed_id`
        FROM `PROFILE_FOLLOW_PROFILE` AS `p`
        WHERE `t`.`Id` = `p`.`Followed_id`
        ORDER BY (SELECT 1)
        LIMIT @__pageSize_3 OFFSET @__p_2
    ) AS `t0`
    INNER JOIN `USER_PROFILES` AS `u0` ON `t`.`Follower_id` = `u0`.`Id`
) AS `t1` ON TRUE
ORDER BY `t`.`Id`, `t1`.`Follower_id`, `t1`.`Followed_id`, `t1`.`Id`"
2020-03-02 20:06:44.308 +01:00 [Error] An exception occurred while iterating over the results of a query for context type '"Cosprea.EntityFrameworkCore.Models.CospreaAPIContext"'."
""MySql.Data.MySqlClient.MySqlException (0x80004005): You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near '(
    SELECT `u0`.`Id`, `u0`.`Bio`, `u0`.`Image`, `u0`.`Name`, `u0`.`Type`, `u0' at line 8

我不知道出了什么问题，在它说的地方添加另一个“(”没有任何意义。

有什么想法吗？

Answer 1

MySQL不支持横向连接