I have this C# code:
string RegisterDate = DateTime.Now.ToString();
RegisterDate = RegisterDate.Remove(10);
RegisterDate = RegisterDate.Replace('/', '-');
RegisterDate = String.Join("-", RegisterDate.Split('-').Reverse());
Which gives thie result: 01-06-2013
The problem is that when I try to insert it to the table I get this result: 21/06/1894
When I get the date via input it works great in the same date format, so why in this case it doesn't work?
update
If I try this:
var RegisterDate = DateTime.Today.Date;
I get Error :
Syntax error (missing operator) in query expression
Wish for help, thanks!
Don't use a string conversion at all. Assuming your data type in the database is DateTime or something similar, just use a parameter and specify its value as the DateTime in your C# code to start with. (I'm assuming you're already using parameterized SQL rather than embedding data straight in your SQL. If you're not using parameters yet, start right away!)
I'd suggest using DateTime.Today to make it clearer that you're only interested in the date part. (Note that this means that the same code running in different places could end up inserting different dates - is that okay? Normally I don't like letting the system local time zone affect things.)
You should generally avoid string conversions unless you really need a string representation of the data. At other times they just cause trouble.
EDIT: You asked for an example. It would be something like:
using (var connection = new SqlConnection(...))
{
connection.Open();
using (var command = new SqlCommand(
"INSERT INTO Foo (Name, RegisterDate) VALUES (#Name, #RegisterDate)",
connection))
{
command.Parameters.Add(new SqlParameter("#Name", SqlDbType.NVarChar))
.Value = name;
// TODO: Consider whether you really want the *local* date, or some
// fixed time zone such as UTC
command.Parameters.Add(new SqlParameter("#RegisterDate", SqlDbType.DateTime))
.Value = DateTime.Today;
command.ExecuteNonQuery();
}
}
Try
string RegisterDate = DateTime.Now.ToString("M-d-yyyy");
and then store in database.
There is no need to manually convert date to different representation. You can go through this Custom Date and Time Format Strings. But, I agree on Jon Skeet's comment below this answer:
If you want to represent a date/time type, use a date/time type. That
way you're able to take advantage of all kinds of things that the
database can do with date/time values, and you'll never get any
non-date/time values in that field.
Note:
DateTime type uses the Gregorian calendar as their default calendar. So, as pointed out by Jon Skeet, this answer won't work with other calenders(Non-Gregorian calendars).
Related
I want to get format of a datetime column to be able to use it in C#. I want to get it and change my variable to this format. I could not find any solution. How to get it? I just want to be able to get the format of existing column and use it as string in C#.
DateTime values in SQL Server are stored as binary values that are not human readable. They are not strings at all.
For C#, you should use the normal .Net primitive DateTime type to talk to the database; NEVER use any string formats; reserve the string for when you output to the user. The ADO.Net library (which also sits underneath other tools like Entity Framework) will efficiently and safely handle transport between your application and SQL Server.
I am building an sql query to search a string value as parameter that comes from frontend.
Great, we can do that. The way we do it to to parse the string to a C# DateTime, and then use the C# DateTime value for the query.
Let me elaborate. I'm worried you're wanting to do something like this:
string SQL = "SELECT * FROM [MyTable] WHERE [DateColumn] >= '" + TextBox1.Text "'";
var cmd = new SqlCommand(SQL, connection);
THAT IS NOT OKAY!
It is NEVER okay to use string concatenation to include user data like that. Instead, you must use parameterized queries. And when you do this, one of the things you can do is provide datetime values.
So instead, the code should look more like this:
string SQL = "SELECT * FROM [MyTable] WHERE [DateColumn] >= #MinDate";
var cmd = new SqlCommand(SQL, connection);
cmd.Parameters.Add("#MinDate", SqlDbType.DateTime).Value = DateTime.Parse(TextBox1.Text);
But even this is still a little rough, because users will do all kinds of things when entering a date into a raw textbox. You'll be much better off if you can also provide a datepicker that ensures you get a clean input from the user.
All that said, the SQL language does have specific formats for Datetime literal values. You can pick any of these formats and the database will handle it correctly:
yyyyMMdd HH:mm:ss[.fff]
yyyy-MM-ddTHH:mm:ss[.fff]
yyyyMMdd
Note the above formats are very specific and must be followed exactly, but if you do any of these can be cleanly converted to SQL Server datetime values. But again: this is not how the values are stored internally, the need for this should be relatively rare, and it's definitely NOT something you would EVER do for user input.
I am trying to pass date to a sql procedure, the time is being passed, and causing the proc to fail, because the times do not match, c# is passing date 12:00:00 database shows date 00:00:00
so here is my code
public class
datetime dt_value;
get the date from the javascript calendar
DT_Value = Convert.ToDateTime(Request.Form["TextBox_Tracking_ImportDate"]);
try to convert to mm/dd/yyyy
string DT_Value2 = DT_Value.ToString("ddMMyyyy");
pass date to sql
cmd.Parameters.Add(new SqlParameter("#import_date", DT_Value2));
ERROR: Error converting data type nvarchar to smalldatetime.
Just pass the DateTime directly..
cmd.Parameters.AddWithValue("#import_date", DT_Value);
See SQL Server Data Type Mappings
This is the first problem:
string DT_Value2 = DT_Value.ToString("ddMMyyyy");
cmd.Parameters.Add(new SqlParameter("#import_date", DT_Value2));
You're performing a pointless string conversion, and as a result you're corrupting the data. Just don't do it. Always avoid string conversions as far as you possibly can.
Pass the DateTime directly:
cmd.Parameters.Add(new SqlParameter("#import_date", DT_Value));
Or better, specify the type explicitly:
cmd.Parameters.Add("#import_date", SqlDbType.Date).Value = DT_Value;
Or to just take the date part explicitly from the DateTime:
cmd.Parameters.Add("#import_date", SqlDbType.Date).Value = DT_Value.Date;
To be honest though, if your SQL code actually knows that the parameter is a Date rather than a DateTime, there shouldn't even be the concept of a time part. If you could post your SQL, that would help us diagnose that aspect. It's really important to work out the right types to use - it makes life so much simpler.
What's wrong with this code?
Client c = new Client();
string format = "yyyy/MM/dd HH:mm:ss";
string dateAdded = now.ToString(format);
c.RegistrationDate = DateTime.Parse(dateAdded);
c.RegistrationDate is a dateTime object in the client class and I want it to insert to my database.
However It doesn't convert the freaking date to the format in my mysql database. It always says that string format is incorrect. WHAT have i done wrong???? should I convert my Registration Date to string??? Thanks
**EDIT: Sorry I've forgot to mention. "now" is now = DateTime.Now; it gets the current time of the date and time.
A DateTime doesnt have a format - it's just the date/time. (Whether it's local time, UTC or whatever is a different matter, mind you.)
Firstly, you shouldn't be converting to and from text like you are: that's just a recipe for trouble. Just use:
c.RegistrationDate = now;
... performing any rounding you need to.
You haven't shown how you're trying to insert the value into your database. If you're including the value in the SQL statement directly, that would explain it. You should be using a parameterized SQL statement and passing the value directly in the parameter - no conversion necessary.
If you're already doing that, please show us the code you're trying to use to insert the data, and we'll see what we can do. See the documentation for some examples.
I don't think there is anything wrong with the c# code,except I assume you must be doing
string dateAdded = DateTime.Now.ToString(format);
Otherwise I am not sure what 'now' is.
I have a table and the date-times in it are in the format:
2011-07-01 15:17:33.357
I am taking a c# DateTime when I do a .ToString() on the object I am getting a DateTime in the format:
04/07/2011 06:06:17
I'm wondering how I correctly pass the correct DateTime through because when I run the SQL that is in our code it doesn't work (i.e. select the correct DateTime). I can't use SQL profiler.
This is the code:
//looks to if a user has had any activity in within the last time specified
public bool IsUserActivitySinceSuppliedTime(int userId, DateTime since)
{
//get everything since the datetime specified [usually 5 hours as this is
//how long the session lasts for
string sql = "SELECT * FROM tbl_webLogging WHERE userid = #userid AND DateAdded > #sinceDateTime";
SqlParameter sinceDateTimeParam = new SqlParameter("#sinceDateTime", SqlDbType.DateTime);
sinceDateTimeParam.Value = since;
SqlCommand command = new SqlCommand(sql);
command.Parameters.AddWithValue("#userid", userId);
command.Parameters.Add(sinceDateTimeParam);
using (SqlDataReader DataReader = GetDataReader(command))
{
if (DataReader.HasRows)
{
return true;
}
else
{
return false;
}
}
}
UPDATE*******************
I have run the following on the data:
SELECT * FROM tbl_webLogging
WHERE userid = 1
AND DateAdded > '2011-07-01 07:19:58.000'
And
SELECT * FROM tbl_webLogging
WHERE userid = 1
AND DateAdded > '04/07/2011 07:19:58'
One returns 53 records the other returns 69 records. How can this be? And when I pass the DateTime (04/07/2011 07:19:58) from c# to SQL no records show up at all!
You've already done it correctly by using a DateTime parameter with the value from the DateTime, so it should already work. Forget about ToString() - since that isn't used here.
If there is a difference, it is most likely to do with different precision between the two environments; maybe choose a rounding (seconds, maybe?) and use that. Also keep in mind UTC/local/unknown (the DB has no concept of the "kind" of date; .NET does).
I have a table and the date-times in it are in the format: 2011-07-01 15:17:33.357
Note that datetimes in the database aren't in any such format; that is just your query-client showing you white lies. It is stored as a number (and even that is an implementation detail), because humans have this odd tendency not to realise that the date you've shown is the same as 40723.6371916281. Stupid humans. By treating it simply as a "datetime" throughout, you shouldn't get any problems.
I had many issues involving C# and SqlServer. I ended up doing the following:
On SQL Server I use the DateTime column type
On c# I use the .ToString("yyyy-MM-dd HH:mm:ss") method
Also make sure that all your machines run on the same timezone.
Regarding the different result sets you get, your first example is "July First" while the second is "4th of July" ...
Also, the second example can be also interpreted as "April 7th", it depends on your server localization configuration (my solution doesn't suffer from this issue).
EDIT: hh was replaced with HH, as it doesn't seem to capture the correct hour on systems with AM/PM as opposed to systems with 24h clock. See the comments below.
I'm trying to call a stored procedure (on a SQL 2005 server) from C#, .NET 2.0 using DateTime as a value to a SqlParameter. The SQL type in the stored procedure is 'datetime'.
Executing the sproc from SQL Management Studio works fine. But everytime I call it from C# I get an error about the date format.
When I run SQL Profiler to watch the calls, I then copy paste the exec call to see what's going on. These are my observations and notes about what I've attempted:
1) If I pass the DateTime in directly as a DateTime or converted to SqlDateTime, the field is surrounding by a PAIR of single quotes, such as
#Date_Of_Birth=N''1/8/2009 8:06:17 PM''
2) If I pass the DateTime in as a string, I only get the single quotes
3) Using SqlDateTime.ToSqlString() does not result in a UTC formatted datetime string (even after converting to universal time)
4) Using DateTime.ToString() does not result in a UTC formatted datetime string.
5) Manually setting the DbType for the SqlParameter to DateTime does not change the above observations.
So, my questions then, is how on earth do I get C# to pass the properly formatted time in the SqlParameter? Surely this is a common use case, why is it so difficult to get working? I can't seem to convert DateTime to a string that is SQL compatable (e.g. '2009-01-08T08:22:45')
EDIT
RE: BFree, the code to actually execute the sproc is as follows:
using (SqlCommand sprocCommand = new SqlCommand(sprocName))
{
sprocCommand.Connection = transaction.Connection;
sprocCommand.Transaction = transaction;
sprocCommand.CommandType = System.Data.CommandType.StoredProcedure;
sprocCommand.Parameters.AddRange(parameters.ToArray());
sprocCommand.ExecuteNonQuery();
}
To go into more detail about what I have tried:
parameters.Add(new SqlParameter("#Date_Of_Birth", DOB));
parameters.Add(new SqlParameter("#Date_Of_Birth", DOB.ToUniversalTime()));
parameters.Add(new SqlParameter("#Date_Of_Birth",
DOB.ToUniversalTime().ToString()));
SqlParameter param = new SqlParameter("#Date_Of_Birth",
System.Data.SqlDbType.DateTime);
param.Value = DOB.ToUniversalTime();
parameters.Add(param);
SqlParameter param = new SqlParameter("#Date_Of_Birth",
SqlDbType.DateTime);
param.Value = new SqlDateTime(DOB.ToUniversalTime());
parameters.Add(param);
parameters.Add(new SqlParameter("#Date_Of_Birth",
new SqlDateTime(DOB.ToUniversalTime()).ToSqlString()));
Additional EDIT
The one I thought most likely to work:
SqlParameter param = new SqlParameter("#Date_Of_Birth",
System.Data.SqlDbType.DateTime);
param.Value = DOB;
Results in this value in the exec call as seen in the SQL Profiler
#Date_Of_Birth=''2009-01-08 15:08:21:813''
If I modify this to be:
#Date_Of_Birth='2009-01-08T15:08:21'
It works, but it won't parse with pair of single quotes, and it wont convert to a DateTime correctly with the space between the date and time and with the milliseconds on the end.
Update and Success
I had copy/pasted the code above after the request from below. I trimmed things here and there to be concise. Turns out my problem was in the code I left out, which I'm sure any one of you would have spotted in an instant. I had wrapped my sproc calls inside a transaction. Turns out that I was simply not doing transaction.Commit()!!!!! I'm ashamed to say it, but there you have it.
I still don't know what's going on with the syntax I get back from the profiler. A coworker watched with his own instance of the profiler from his computer, and it returned proper syntax. Watching the very SAME executions from my profiler showed the incorrect syntax. It acted as a red-herring, making me believe there was a query syntax problem instead of the much more simple and true answer, which was that I need to commit the transaction!
I marked an answer below as correct, and threw in some up-votes on others because they did, after all, answer the question, even if they didn't fix my specific (brain lapse) issue.
How are you setting up the SqlParameter? You should set the SqlDbType property to SqlDbType.DateTime and then pass the DateTime directly to the parameter (do NOT convert to a string, you are asking for a bunch of problems then).
You should be able to get the value into the DB. If not, here is a very simple example of how to do it:
static void Main(string[] args)
{
// Create the connection.
using (SqlConnection connection = new SqlConnection(#"Data Source=..."))
{
// Open the connection.
connection.Open();
// Create the command.
using (SqlCommand command = new SqlCommand("xsp_Test", connection))
{
// Set the command type.
command.CommandType = System.Data.CommandType.StoredProcedure;
// Add the parameter.
SqlParameter parameter = command.Parameters.Add("#dt",
System.Data.SqlDbType.DateTime);
// Set the value.
parameter.Value = DateTime.Now;
// Make the call.
command.ExecuteNonQuery();
}
}
}
I think part of the issue here is that you are worried that the fact that the time is in UTC is not being conveyed to SQL Server. To that end, you shouldn't, because SQL Server doesn't know that a particular time is in a particular locale/time zone.
If you want to store the UTC value, then convert it to UTC before passing it to SQL Server (unless your server has the same time zone as the client code generating the DateTime, and even then, that's a risk, IMO). SQL Server will store this value and when you get it back, if you want to display it in local time, you have to do it yourself (which the DateTime struct will easily do).
All that being said, if you perform the conversion and then pass the converted UTC date (the date that is obtained by calling the ToUniversalTime method, not by converting to a string) to the stored procedure.
And when you get the value back, call the ToLocalTime method to get the time in the local time zone.
Here is how I add parameters:
sprocCommand.Parameters.Add(New SqlParameter("#Date_Of_Birth",Data.SqlDbType.DateTime))
sprocCommand.Parameters("#Date_Of_Birth").Value = DOB
I am assuming when you write out DOB there are no quotes.
Are you using a third-party control to get the date? I have had problems with the way the text value is generated from some of them.
Lastly, does it work if you type in the .Value attribute of the parameter without referencing DOB?
Just use:
param.AddWithValue("#Date_Of_Birth",DOB);
That will take care of all your problems.
If you use Microsoft.ApplicationBlocks.Data it'll make calling your sprocs a single line
SqlHelper.ExecuteNonQuery(ConnectionString, "SprocName", DOB)
Oh and I think casperOne is correct...if you want to ensure the correct datetime over multiple timezones then simply convert the value to UTC before you send the value to SQL Server
SqlHelper.ExecuteNonQuery(ConnectionString, "SprocName", DOB.ToUniversalTime())