MySQL LAG/LEAD 问题

Question

我正在尝试将一些代码从我当前的主机移动到 GoDaddy，但遇到 LEAD/LAG 的问题。

我的代码中有以下 SQL 语句：

SELECT 
  id, 
  LAG(Clients.id,1) OVER w AS 'lag', 
  LEAD(Clients.id,1) OVER w AS 'lead' 
FROM Clients 
WHERE custno IS NOT NULL 
WINDOW w AS (ORDER BY Clients.id)

在我当前的主机上，运行完美。他们是运行ning 10.3.29-MariaDB。

GoDaddy 运行宁 5.6.49-cll-lve MySQL。我在尝试运行完全相同的查询时收到以下一批错误：

20 errors were found during analysis.

An alias was previously found. (near "w" at position 34)
Unexpected token. (near "w" at position 34)
Unrecognized keyword. (near "AS" at position 36)
Unexpected token. (near "'lag'" at position 39)
Unexpected token. (near "," at position 44)
Unexpected token. (near "LEAD" at position 46)
Unexpected token. (near "(" at position 50)
Unexpected token. (near "Clients" at position 51)
Unexpected token. (near "." at position 58)
Unexpected token. (near "id" at position 59)
Unexpected token. (near "," at position 61)
Unexpected token. (near "1" at position 62)
Unexpected token. (near ")" at position 63)
Unexpected token. (near "OVER" at position 65)
Unexpected token. (near "w" at position 70)
Unrecognized keyword. (near "AS" at position 72)
Unexpected token. (near "'lead'" at position 75)
Unrecognized keyword. (near "AS" at position 129)
Unexpected token. (near "(" at position 132)
Unexpected token. (near ")" at position 152)

有什么建议吗？

Answer 1

您运行此代码在不支持 window 功能的 MySql 版本中（您需要 MySql 8.0+）。

相反，您可以使用相关子查询：

SELECT 
  c.id,
  (SELECT MAX(cc.id) FROM Clients cc WHERE cc.id < c.id) AS `lag`,
  (SELECT MIN(cc.id) FROM Clients cc WHERE cc.id > c.id) AS `lead`  
FROM Clients c 
WHERE c.custno IS NOT NULL

MySQL LAG/LEAD 问题

MySQL LAG/LEAD issue

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