MySQL查询错误1064

Question

I try to use a query about finding users around with this query:

                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

but I have this error:

 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

I don't understand the error..

Answer 1

long is a reserved keyword . If you're going to name a column identifier that you must wrap it in ticks:

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 is an reserved keyword , you're not allowed to use iut like that because it has another meaning in mysql.

You can use it by using backticks (like the single quotes in php make things litteral):

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

To make it a bit more obvious, say you have a column in your database called select :

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