MySQL查询错误1064

Question

我尝试使用有关通过此查询查找用户的查询：

                Select id, username, lat, long,
                    acos(sin(0.761312289853)*sin(radians(lat)) + cos(0.761312289853)*cos(radians(lat))*cos(radians(long)-0.0676354285243)) * 6371 As D
                From (
                    Select id, username, lat, long,
                    From rcp_users
                    Where lat Between 43.4491099949 And 43.7908522051
                      And long Between 3.63919239657 And 4.11125680343
                ) As FirstCut
                Where acos(sin(0.761312289853)*sin(radians(lat)) + cos(0.761312289853)*cos(radians(lat))*cos(radians(long)-0.0676354285243)) * 6371 < 30
                Order by D

但是我有这个错误：

 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 'long,
                    acos(sin(0.761312289853)*sin(radians(lat)) + cos(0.761312289853)*' at line 1

我不明白错误。

Answer 1

long是保留关键字 。 如果要命名列标识符，则必须将其包装在刻度中：

Select id, username, lat, `long`,
    acos(sin(0.761312289853)*sin(radians(lat)) + cos(0.761312289853)*cos(radians(lat))*cos(radians(`long`)-0.0676354285243)) * 6371 As D
From (
    Select id, username, lat, `long`,
    From rcp_users
    Where lat Between 43.4491099949 And 43.7908522051
      And `long` Between 3.63919239657 And 4.11125680343
) As FirstCut
Where acos(sin(0.761312289853)*sin(radians(lat)) + cos(0.761312289853)*cos(radians(lat))*cos(radians(`long`)-0.0676354285243)) * 6371 < 19
Order by D

Answer 2

long是一个保留关键字 ，不允许使用iut，因为它在mysql中具有另一种含义。

您可以通过使用反引号来使用它（例如php中的单引号会使内容乱七八糟）：

SELECT id, username, lat, `long` FROM table

为了使它更加明显，假设您在数据库中有一列名为select的列：

SELECT id,username,select FROM table // this will not work, select is reserved