为什么DateTime.Now在asp.net c＃中保存到SQL YYYY-DD-MM？

Question

I tried save DateTime.Now to SQL but column data created like this

2014-06-02 22:30:19.000

But I want it to be like

2014-02-06 22:30:19.000

or

06-02-2014 22:30:19.000

My codes:

conn.Open();
var commandSQL= new SqlCommand(@"INSERT INTO TableName(SaveTime) 
values (@SaveTime) ", conn);
commandSQL.Parameters.AddWithValue("SaveTime",DateTime.Now.ToString());   
commandSQL.ExecuteNonQuery();

Answer 1

DateTime in .Net framework and SQL Server doesn't have any format. You should add the DateTime object directly instead of calling ToString

Just remove the ToString when adding value with parameter

commandSQL.Parameters.AddWithValue("@SaveTime",DateTime.Now);

(You are missing @ with your parameter, but I don't think that is the issue here)

Format is only useful for displaying purpose.

Answer 2

SQL Server is perfectly happy to take a string value for any data type, provided there is an implicit conversion defined from string to that datatype , viz:

So...

What is the data type of your column SaveTime ?

If it is datetime , smalldatetime , datetime2 or date , it means that you're converting a CLR DateTime to a string, which is then converted to the SQL Server datatype with the precision implicit with that datatype. And, it has not representation until you give it one. Further, there is a possible loss of precision: the finest precision of the resulting SQL Server value is limited by the implicit precision of the string representation you sent to SQL Server.

If the column's data type is something else — char , nchar , varchar , nvarchar — it will be stored exactly as the string representation you sent up to SQL Server, with all that implies. When you convert a C# System.DateTime to a string, the default conversion format used is dependent upon the current value of CultureInfo.CurrentCulture for the thread upon which the conversion is performed.

Just add the C# DateTime value directly as the value of the parameter: you don't need to convert it to a string. Let the infrastructure do the work for you.