前景提要：現有一批房屋數據，房屋的計量單位字段定義為Square，字段類型是varchar（50）。為的是便於用戶輸入資料：房屋單位可能是平米，那輸入的數據就是28.5等等之類的數字。亦可能是 1 間。
客戶要求：有面積的房屋顯示面積，沒有面積、以間為單位的房屋顯示為0.
解決方法如下：
create proc Asset_QueryFenlistForReport
(
@pi_Action varchar(100),
@pi_PropertyCode varchar(100),
@pi_pageIndex INT,
@pi_pageSize INT,
@po_recordCount BIGINT OUTPUT
)
as
DECLARE @pt_StartRowIndex INT
DECLARE @pt_EndRowIndex INT
SET @pt_StartRowIndex = (@pi_pageIndex - 1) * @pi_pageSize + 1
SET @pt_EndRowIndex = @pi_pageIndex * @pi_PageSize
IF @pi_Action = 'getlist'
BEGIN
SELECT * FROM
(
SELECT Asset_ShopInfo.RentStatus, Asset_ShopInfo.RefRental, Asset_ShopInfo.BuildingCode, Asset_ShopInfo.ShopCode, Asset_ShopInfo.Square,
Asset_Contract.RendStartDate, Asset_Contract.RendEndDate, Asset_ShopInfo.PropertyCode
,'SquareNew'=(
case
--使用函數ISNUMERIC(參數)
when ISNUMERIC ([Square])=0 then '0'
--當輸入表達式得數為一個有效的整數、浮點數、money 或 decimal 類型，那么 ISNUMERIC 返回 1；否則返回 0。
when ISNUMERIC ([Square])>0 then [Square]
end
),
'RentStatuss' = (
CASE
WHEN RentStatus = 0 THEN '空置'
WHEN RentStatus = 1 THEN '預定'
ELSE
'已租'
End),
'YearRefRental'=(RefRental * 12),
ROW_NUMBER() OVER (ORDER BY Asset_Contract.RendStartDate DESC) AS RowIndex
FROM Asset_Contract INNER JOIN
Asset_ContractShopInfo ON Asset_Contract.ContractCode = Asset_ContractShopInfo.ContractCode RIGHT OUTER JOIN
Asset_ShopInfo ON Asset_ContractShopInfo.ShopCode = Asset_ShopInfo.ShopCode
where Asset_ShopInfo.propertycode = @pi_propertycode
)bb
WHERE RowIndex BETWEEN @pt_StartRowIndex AND @pt_EndRowIndex
--得到總數
SELECT @po_recordCount = COUNT(*)
FROM Asset_Contract INNER JOIN
Asset_ContractShopInfo ON Asset_Contract.ContractCode = Asset_ContractShopInfo.ContractCode RIGHT OUTER JOIN
Asset_ShopInfo ON Asset_ContractShopInfo.ShopCode = Asset_ShopInfo.ShopCode
where Asset_ShopInfo.propertycode = @pi_propertycode
END