我有将在SQL Server中的电子邮件中填充html表的代码。一些字段是日期字段。我想建立一个if语句，说如果到期日期是从今天的日期起过去30天之内，则单元格的背景为黄色。如果从今天算起过去60天过去了，则该单元格的背景为红色。我怎么能只给一个单元着色？
Set @TableTail = '</table></body></html>';
Set @TableHead = '<html><head>' +
'<style>' +
'td {border: padding-left:5px;padding-right:5px;padding-top:1px;padding-bottom:1px;font-size:11pt;} ' +
'</style>' +
'</head>' +
'<body><table cellpadding=0 cellspacing=0 border=0>' +
'<tr bgcolor=#FFEFD8><td align=left><b>Principal</b></td>' +
'<td align=left><b>Company</b></td>' +
'<td align=left><b>Action Item</b></td>' +
'<td align=left><b>Sales</b></td>' +
'<td align=left><b>Due Date</b></td>' +
'<td align=left><b>Updated</b></td>' +
'<td align=left><b>Owner</b></td></tr>';
DECLARE @CNT as int, @SLS as NVARCHAR(10)
select [employeeid], [Sales], [Email Address]
into #loctempemployee from tblEmployees
Set @CNT = (Select COUNT (Distinct EmployeeID) from #loctempemployee)
While (@CNT > 0)
begin
Set @message=
(
SELECT tr.Principal As [TD], tr.[Company Name] As [TD], ai.[Action Item] As [TD], ai.Owners As [TD], LEFT((ai.[Due Date]),10) As [TD], LEFT((ai.Updated),10) As [TD], em.Sales As [TD]
FROM [tblActionItem] ai
INNER JOIN tblTripReport tr ON ai.TripReportID = tr.tripreportID
INNER JOIN tblCustomers cu ON cu.CustomerID = tr.[Customer ID]
INNER JOIN tblEmployees em ON em.EmployeeID = cu.EmployeeID
WHERE em.Sales = (Select sales from #loctempemployee Where EmployeeID = (Select top 1 EmployeeID from #loctempemployee))
For XML raw('tr'), Elements
)
Select @Body = (@message)
Set @Body = Replace(@Body, '_x0020_', space(1))
Set @Body = Replace(@Body, '_x003D_', '=')
Set @Body = Replace(@Body, '<tr><TRRow>1</TRRow>', '<tr bgcolor=#C6CFFF>')
Set @Body = Replace(@Body, '<TRRow>0</TRRow>', '')
Select @Body = @TableHead + @Body + @TableTail