MySQL 报告 : Documentation #1064 - There is something wrong in the syntax used with "" on rule 3

Question

我目前正在为学校做一项作业，我必须编写一个查询，但遇到错误。

分配如下:如果客户 A 访问分行 1，客户 B 访问分行 1 和 2，客户 C 访问分行 2，那么可以说客户 A 和 B 0 分行相互分离，客户 A 和 C 1 分行相互分离。找出两个随机客户相距多少个分行。

我收到此错误

SQL-query: Documentatie
SELECT DISTINCT a.klant_idklant AS "KLANT A", b.klant_idklant AS "KLANT B", a.filiaal_idfiliaal AS "FILIAAL A", b.filiaal_idfiliaal AS "FILIAAL B", ABS(a.filiaal_idfiliaal - b.filiaal_idfiliaal) AS "FILIALEN VAN ELKAAR VERWIJDERD"
FROM aankoop a, aankoop b 
WHERE a.klant_idklant = FLOOR(RAND()(SELECT MAX(idklant) FROM klant) - (SELECT MIN(idklant) FROM klant) + (SELECT MIN(idklant) FROM klant))
AND b.klant_idklant = FLOOR(RAND()(SELECT MAX(idklant) FROM klant) - (SELECT MIN(idklant) FROM klant) + (SELECT MIN(idklant) FROM klant)) LIMIT 0, 25

MySQL reports: Documentation
#1064 - There is something wrong in the syntax used with '(SELECT MAX(idklant) FROM klant) - (SELECT MIN(idklant) FROM klant) + (SELECT MI' on rule 3

这是我当前的查询

SELECT DISTINCT a.klant_idklant AS "KLANT A"
              , b.klant_idklant AS "KLANT B"
              , a.filiaal_idfiliaal AS "FILIAAL A"
              , b.filiaal_idfiliaal AS "FILIAAL B"
              , ABS(a.filiaal_idfiliaal - b.filiaal_idfiliaal) AS "FILIALEN VAN ELKAAR VERWIJDERD"
           FROM aankoop a
              , aankoop b 
          WHERE a.klant_idklant = FLOOR(RAND()(SELECT MAX(idklant) FROM klant) - 
                                              (SELECT MIN(idklant) FROM klant) + 
                                              (SELECT MIN(idklant) FROM klant)
                                       )
            AND b.klant_idklant = FLOOR(RAND()(SELECT MAX(idklant) FROM klant) - 
                                              (SELECT MIN(idklant) FROM klant) + 
                                              (SELECT MIN(idklant) FROM klant)
                                       )

这是 Database Structure

Answer 1

问题是您没有将子查询的结果与 RAND() 相乘。你应该有:

SELECT DISTINCT a.klant_idklant AS "KLANT A"
              , b.klant_idklant AS "KLANT B"
              , a.filiaal_idfiliaal AS "FILIAAL A"
              , b.filiaal_idfiliaal AS "FILIAAL B"
              , ABS(a.filiaal_idfiliaal - b.filiaal_idfiliaal) AS "FILIALEN VAN ELKAAR VERWIJDERD"
           FROM aankoop a
              , aankoop b 
          WHERE a.klant_idklant = FLOOR(RAND()*(SELECT MAX(idklant) FROM klant) - 
                                              (SELECT MIN(idklant) FROM klant) + 
                                              (SELECT MIN(idklant) FROM klant)
                                       )
            AND b.klant_idklant = FLOOR(RAND()*(SELECT MAX(idklant) FROM klant) - 
                                              (SELECT MIN(idklant) FROM klant) + 
                                              (SELECT MIN(idklant) FROM klant)