sql - 如何从 DATETIME 列获取日期？

Question

我想从 DateTime 列中获取日期。

<asp:SqlDataSource ID="SqlDataSource1" runat="server" 
ConnectionString="<%$ ConnectionStrings:ConnectionString %>" 
SelectCommand="SELECT [name], [book_id], [book_name], [taken_date], [last_date], [renewed_date], [status], [comment], [fine_amount] FROM [library] WHERE ([admn_no] = @admn_no)">
<SelectParameters>
   <asp:ControlParameter ControlID="TextBox1" Name="admn_no" PropertyName="Text" 
   Type="String" />
</SelectParameters>
</asp:SqlDataSource>

从上面这些 [拍摄日期],[最后日期],[续订日期] 显示日期和时间的列

(eg: 4/14/2015 12:00:00 AM).

如何仅显示日期

(eg: 4/14/2015)?

Answer 1

对于 Sql-server 2008 及以上版本，您可以使用 CAST(column_name AS DATE)

SELECT [name], [book_id], [book_name], 
cast([taken_date] as date) as [taken_date], 
cast([last_date] as date) as [last_date], 
cast([renewed_date] as date) as [renewed_date], 
[status], [comment], [fine_amount] 
FROM [library] WHERE ([admn_no] = @admn_no)

编辑 1

对于 sqlserver 2008 之前的早期版本，您可以这样做

SELECT CONVERT(VARCHAR(10),GETDATE(),111)

所以整个查询将像这样

SELECT [name], [book_id], [book_name], 
CONVERT(VARCHAR(10),[taken_date],111) as [taken_date], 
CONVERT(VARCHAR(10),[last_date],111) as [last_date], 
CONVERT(VARCHAR(10),[renewed_date],111) as [renewed_date], 
[status], [comment], [fine_amount] 
FROM [library] WHERE ([admn_no] = @admn_no)

编辑2

要将日期格式从 yyyy/dd/mm 更改为 dd/mm/yyyy，您可以更改为 101 而不是 111

SELECT CONVERT(VARCHAR(10),GETDATE(),101)

所以查询将是

SELECT [name], [book_id], [book_name], 
CONVERT(VARCHAR(10),[taken_date],101) as [taken_date], 
CONVERT(VARCHAR(10),[last_date],101) as [last_date], 
CONVERT(VARCHAR(10),[renewed_date],101) as [renewed_date], 
[status], [comment], [fine_amount] 
FROM [library] WHERE ([admn_no] = @admn_no)