在我的Pivot MYSQL代码上获取语法错误这是我的代码

Question

SELECT VendorID,[250] AS "Emp1",[251] AS "Emp2",[252] AS "Emp3",[253] AS "Emp4",[254] AS "Emp5"
FROM (SELECT
    PurchaseOrderID
   ,EmployeeID
   ,VendorID
  FROM Purchasing.PurchaseOrderHeader) p

PIVOT
(
  COUNT(PurchaseOrderID) FOR EmployeeID IN ([250], [251], [252], [253], [254])
) AS t
ORDER BY t.VendorID;

我收到此错误

错误1064（42000）：您的SQL语法有错误;检查与您的MySQL服务器版本相对应的手册，以便使用正确的语法，以便在[...] [Emp]，[251] AS Emp2，[252] AS Emp3，[253] AS Emp4，[254] AS Emp5FR＆ ＃39;在第3行