mysql - SQL 查询错误 #1064

Question

所以我有这个查询:

SELECT 
   t1.password 
FROM Session AS t1 
INNER JOIN Locations AS t2 ON 
    t2.id = t1.location_id AND 
    SQRT( POWER( CONVERT(t2.longitude,float(10)) - 132.456, 2) + 
        POWER( CONVERT(t2.latitude,float(10)) - 132.456, 2) ) < 100 
WHERE t1.end_distribution = 0 AND t1.end_session = 0

我明白了:

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 'float(10)) - 132.456, 2) + POWER( CONVERT(t2.latitude,float(10)) - 132.456, 2) )' at line 13

Answer 1

使用

CONVERT(t2.longitude, float(10))

MySQL CONVERT SYNTAX

更新

根据上面的文档，您不能将表达式转换为浮点类型，而是使用小数。

CONVERT(t2.longitude, decimal(10))