如何修复对未定义函数mysql_real_escape_string（）的调用错误

Question

当我尝试登录时，出现此错误。

  

调用未定义函数mysql_real_escape_string（）

这是文件的代码：

SELECT (p.LastName + ' ' + p.FirstName) AS 'Customer', s.CustomerID AS 'CustomerId',    YEAR(s.OrderDate) AS Rok, SUM(s.SubTotal) AS 'Amount', COUNT(*) AS 'number of purchases'

FROM Sales.SalesOrderHeader s JOIN Sales.Customer c ON s.CustomerID = c.CustomerID
JOIN Person.Person p ON c.PersonID = p.BusinessEntityID

GROUP BY s.CustomerID,  YEAR(s.OrderDate), p.LastName, p.FirstName

ORDER BY  s.CustomerID, YEAR(s.OrderDate);

预期结果是在我登录后说您已成功登录。我该如何解决？