Question

我一直在尝试执行下面的代码，但它没有运行。 SQLFiddle提供

您的SQL语法有错误;检查与MySQL服务器版本对应的手册，以便在第2行'.'EO' AS 'EO','EF'.'AC' AS 'AC','EO''附近使用正确的语法

我不知道我做错了什么。

SELECT DISTINCT 'EO'.'EO' AS 'EO', 'EF'.'AC' AS 'AC', 'EO'.'WO' AS 'WO', 'EO'.'WOF' AS 'WOF', 'EF'.'PN_SN' AS 'PN_SN', 'EC'.'CD' AS 'CD', 'EF'.'PN' AS 'PN', 'EO'.'EOC' AS 'EOC', 'EO'.'STAT' AS 'STAT', 'EF'.'OVRD' AS 'OVRD', 'EF'.'SEL' AS 'SEL', 'EF'.'ED' AS 'ED', 'EF'.'SCHED' AS 'SCHED', 'EF'.'SAD' AS 'SAD', 'EF'.'SA' AS 'SA', 'EO'.'EOD' AS 'EOD' FROM EO, EC, EF WHERE ( 'EO'.'EO' = 'EC'.'EO' ) AND ( 'EF'.'PSN' = 'EC'.'PSN' ) AND ( 'EO'.'WB' = 'Y' ) AND ( 'EC'.'CONT' = 'W & B' ) ; SELECT 'EC'.'RSTD' AS 'RSTD' FROM EC RIGHT JOIN EF ON ( 'EF'.'EO' = 'EC'.'EO' ) ON ( 'EF'.'AC' = 'EC'.'AC' ) ON ( 'EF'.'PN' = 'EC'.'PN' ) ON ( 'EF'.'PSN' = 'EC'.'PSN' )

Answer 1

单引号 - ' - 适用于文字。使用双引号 - " - 用于标识符...

 SELECT
    "EC"."RSTD"
    FROM EC RIGHT JOIN EF
      ON ( "EF"."EO" = "EC"."EO" ) 
      ON ( "EF"."AC" = "EC"."AC" ) 
      ON ( "EF"."PN" = "EC"."PN" ) 
      ON ( "EF"."PSN' = "EC"."PSN" )

......或者更好的是，完全省略它们：

 SELECT
    EC.RSTD
    FROM EC RIGHT JOIN EF
      ON ( EF.EO = EC.EO ) 
      ON ( EF.AC = EC.AC ) 
      ON ( EF.PN = EC.PN ) 
      ON ( EF.PSN = EC.PSN )

显然，在适当时保留单引号，例如将列与文字进行比较：

where EO.WB = 'Y'

另请注意，在不更改列名时不必使用列别名：select ec.rstd as rstd是多余的，实际上很烦人。保留用于重命名列的用途，例如select ec.rstd as my_new_col_name

SQL错误运行查询时

1 个答案: