I use GETDATE() in a SQL Server stored procedure to insert a date into the SQL Server database table.
After that I need to implement a C# function which is based on datetime input parameter finds if the date was saved in the tables.
The datetime in C# and SQL are different. How do I convert from C# datetime to SQL datetime which has a form of yyyy-mm-ddT:yy:mm:ss.mmm? I need to specify explicitly yyyy-mm-ddT:yy:mm:ss.mmm.
Will be happy for all propositions/possible ways.
DateTime in .Net framework and SQL Server (if it is DateTime type field) is irrespective of the format. Format is only useful for displaying output.
If your field in SQL Server is of DateTime type then you can query it from C# code using parameterized query something like:
public DataTable GetRecords(DateTime dtParameter)
{
DataTable dt = null;
using (SqlConnection conn = new SqlConnection("connection string"))
{
using (SqlCommand cmd = new SqlCommand("SELECT * from yourTable where DateField = #dateparameter"))
{
conn.Open();
cmd.Parameters.AddWithValue("#dateparameter",dtParameter);
SqlDataReader dr = cmd.ExecuteReader();
//...rest of the code
dt.Load(dr);
}
}
return dt;
}
Datetimes between C# and SQL are 100% compatible. The format shouldn't make any difference if you are passing them as DateTimes. If you are generating a SQL string then I would highly recommend changing to SQL Parameters so you don;t have to worry about any formatting issues.
A datetime has no format at all, it has a value. SQL-DateTimes and C# DateTimes are compatible. So don't convert it (to string) at all but pass it as datetime-parameter to the database.
Then you're safe if the DateTime value is within SqlDateTime.MinValue(January 1, 1753) and SqlDateTime.MaxValue(December 31, 9999).
You should never write DateTime.Now from client code to insert into the database as this will be based on the clients local time; do this
public DateTime GetDatabaseTime()
{
var parameter = new SqlParameter("time", SqlDbType.DateTime2)
{
Direction = ParameterDirection.Output
};
using (var connection = new SqlConnection(ConnectionString))
{
connection.Open();
using (var command = new SqlConnection("SELECT #time = SYSDATETIME()", connection))
{
command.ExecuteNonQuery();
}
}
return (DateTime)parameter.Value;
}
Also you should never use DATETIME in SQL Server you should always use DATETIME2 as DATETIME is less accurate than C#::DateTime and it will lead to rounding errors. I know this from bitter experience.
If you are using Entity Framework, and your database is using datetime and not datetime2, the trick is to use SqlDateTime to match the fact that .Net goes to nanosecond, versus sql's millisecond precision. You can use your DateTime variable in .net.. for a SqlDateTime instance, and then you can uniquely identify a record down to the millisecond.
System.Data.SqlTypes.SqlDateTime entry2 = new System.Data.SqlTypes.SqlDateTime(new DateTime(dto.LookUpDateTime));
DateTime entry = entry2.Value;
var existticket = from db in context.Tickets
where db.LookupDateTime == entry && db.UserId == UserId
select db;
Related
I am inserting a DateTime attribute into a sqlite database and its getting stored successfully as 2018-04-09T00:00:00.0000000-03:00 for the appropriate time. When I attempt to retrieve it from the database it only returns 2018. Why won't it return the full value?
my insert is:
using (SQLiteConnection conn = new SQLiteConnection(Utility.CONN_STR))
{
conn.Open();
SQLiteCommand cmd = new SQLiteCommand("INSERT into Waybill (createdOn) VALUES(#createdOn)", conn);
cmd.Parameters.AddWithValue("#createdOn", waybillP.CreatedOn);
cmd.ExecuteNonQuery();
}
createdOn is a DateTime.
My select is:
using (SQLiteConnection conn = new SQLiteConnection(Utility.CONN_STR))
{
conn.Open();
SQLiteCommand cmd = new SQLiteCommand("SELECT * FROM Waybill where WaybillId = (select max(waybillId) from Waybill);", conn);
SQLiteDataReader reader = cmd.ExecuteReader();
while (reader.Read())
{
int waybillId = Convert.ToInt16(reader["waybillId"].ToString());
var temp = reader["createdOn"].ToString();
DateTime createdOn = DateTime.Parse(temp);
waybill.WaybillId = waybillId;
waybill.CreatedOn = createdOn;
}
Temp is only returning 2018 instead of 2018-04-09T00:00:00.0000000-03:00.
I have tried setting the DB column to text, real, and integer with the same results.
I have also tried using SQLites datetime formatting like so:
SQLiteCommand cmd = new SQLiteCommand("INSERT into Waybill (createdOn) VALUES(datetime('now'))", conn);
every attempt just returns 2018 no matter what the actual entry in the DB looks like.
This causes the DateTime.Parse to crash as 2018 isn't a recognized date time.
Any help would be appreciated.
Chetan's solution worked for me since I am only returning one result and I know the contents of the reader to be able to select the index.
var createdOn = reader.GetDateTime(1);
So for anyone reaching here after so much searching:
The Problem:
your datetime record in your sqlite database might look like this: 2019-11-24T08:43:52.1083280Z and when you try to parse your date field into either a string or DateTime or even a dynamic field you only get until the first hyphen in this case 2019.
I'm using the System.Data.Sqlite and Dapper packages.
since I did not have enought time to investigate this thoroughly, this code helped me:
The Solution:
first alter your query to return something other than that date format:
select strftime('%Y%m%dT%H%M%S', created) as created from contacts
then you can either parse that format in your code or implement a custom TypeHandler for Dapper.
Parsing the custom format:
DateTime.SpecifyKind(DateTime.ParseExact(value, "yyyyMMddTHHmmss", CultureInfo.InvariantCulture), DateTimeKind.Utc)
Custom Dapper TypeHandler:
public class DateTimeHandler : SqlMapper.TypeHandler<DateTime>
{
public override void SetValue(IDbDataParameter parameter, DateTime value)
{
parameter.Value = value.ToString("YYYYMMDDTHHmmss");
}
public override DateTime Parse(object value)
{
return DateTime.SpecifyKind(DateTime.ParseExact((string)value, "yyyyMMddTHHmmss", CultureInfo.InvariantCulture), DateTimeKind.Utc);
}
}
Which you have to register it in the begining of your application for example in Global.asax:
protected void Application_Start()
{
SqlMapper.AddTypeHandler(new DateTimeHandler());
}
an error while storing date in DB (SQL server 2005) using C#
I am using,
DateTime mydate = DateTime.Now;
insert into mytablename (appdate) values('"+mydate.ToShortDateString()+"');
bt its showing error when I run the query
also tried,
mydate.ToShortDateString().ToString("dd-MMM-yyyy HH:mm:ss") in C# , still showing error in editor only.
How do I store 'date' in SQL Server 2005 using C# query
Use parameterized SQL, and set the value into the parameter:
string sql = "insert into tablename (appdate) values (#appdate)";
using (var connection = new SqlConnection(...))
{
connection.Open();
using (var command = new SqlCommand(sql, connection))
{
command.Parameters.Add("#appdate", SqlDbType.DateTime).Value
= DateTime.Now;
int rowsInserted = command.ExecuteNonQuery();
// TODO: Validation of result (you'd expect it to be 1)
}
}
You should always use parameterized SQL when you have data to include in the request to the database. This avoids SQL injection attacks and data conversion issues, as well as keeping your code cleaner.
You should also consider whether you really want it to be the local date/time or the UTC date/time. For example, you might want to use DateTime.UtcNow instead.
Your query tries to insert a string in a DateTime field. And of course it doesn't work.
The correct way to insert is through a parametrized query like this
string insertSQL = "insert into mytablename (appdate) values(#dt)";
SqlCommand cmd = new SqlCommand(insertSQL, con);
cmd.Parameters.AddWithValue("#dt", mydate);
cmd.ExecuteNonQuery();
Here I assume that the connection is already initialized and opened
my question looks simple: in my client/server application I want to record a specific date provided by the client.
The problem is that I don't know the regional settings of the client, and I don't know the regional settings of the SQL Server.
How can the client application provide a date in whatever format (last login of a specific user) and store it in a SQL Server table that might be installed with a different regional settings (french, english, italian, german, etc...).
Simple: don't use strings. Use a parameter that is typed as a datetime; can be as simple as:
DateTime when = ...
using(var cmd = conn.CreateCommand()) {
cmd.CommandText = "... #when ...";
cmd.Parameters.AddWithValue("when", when);
cmd.ExecuteNotQuery();
}
or with "dapper":
conn.Execute("... #when ...", new { when });
Dates/times are actually just numbers. It is only when you write/parse it as a string that formatting is an issue.
Just store everything in UTC date in sqlserver. And while retrieving the date convert the utc date to the timezone of the user. I hope users timezone is maintained in your database.
You will need a timezone table and a conversion function that will convert the UTC time to the users local time.
to insert a date in SQL use a string in the form 'YYYYMMDD'
what comes from the client-side you sould know what is it
You should use Parameters, but you also can format date to ISO format by date.ToString("s")
Use datetime format, and store dates as UTC time.
You'll probably also be interested in datetimeoffset.
Validation part
DateTime dt;
string YourDate = "Your Date";
if (DateTime.TryParse(YourDate, out dt))
{
//Your Code
}
Stored Procedure Record Insertion/Retrieval
using (System.Data.SqlClient.SqlConnection con = new SqlConnection("YourConnection string"))
{
con.Open();
SqlCommand cmd = new SqlCommand();
string expression = "Date Parameter value";
DateTime dt;
if (DateTime.TryParse(expression, out dt))
{
//Your Code
}
cmd.CommandType = CommandType.StoredProcedure;
cmd.CommandText = "Your Stored Procedure";
cmd.Parameters.Add("Your Parameter Name", SqlDbType.VarChar).Value = expression;
cmd.Connection = con;
using (IDataReader dr = cmd.ExecuteReader())
{
if (dr.Read())
{
}
}
}
While storing the data in Sql Server Keep the data format consistent and synchronized with the data format while retrieving....
How to convert C# datetime to MySql Datetime format. I am getting value from text box like 7/27/2011 this format. But i want to convert in this format 2011-7-27. So here i am stuking. Please help me. My objective is to filter the record between two dates and show in a listview control in asp.net.
Here is my code:
DateTime dt1 = Convert.ToDateTime(txtToDate.Text);
DateTime dt2 = Convert.ToDateTime(txtFromDate.Text);
lvAlert.DataSource = facade.GetAlertsByDate(dt1, dt2);
lvAlert.DataBind();
I haven't used MySQL with .NET, but Oracle has similar date conversion issues with .NET. The only way to stay snae with this has been to use parameters for date values, both for input as welll as for WHERE clause comparisons. A parameter created with a MySQL date parameter type, and just giving it a .NET datetime value, should work without needing you to do conversions.
EDITED TO ADD SAMPLE CODE
This code sample shows the basic technique of using parameters for DateTime values, instead of coding conversions to text values and embedding those text values directly in the SQL command text.
public DataTable GetAlertsByDate(DateTime start, DateTime end)
{
SqlConnection conn = new SqlConnection(connectionString);
SqlCommand cmd = new SqlCommand(
"SELECT * FROM Alerts WHERE EventTime BETWEEN #start AND #end", conn);
DataTable table = new DataTable();
try
{
SqlParameter param;
param = new SqlParameter("#start", SqlDbType.DateTime);
param.Value = start;
cmd.Parameters.Add(param);
param = new SqlParameter("#end", SqlDbType.DateTime);
param.Value = end;
cmd.Parameters.Add(param);
SqlDataAdapter da = new SqlDataAdapter(cmd);
da.Fill(table);
}
finally
{
cmd.Dispose();
conn.Close();
conn.Dispose();
}
return table;
}
This is SQL Server code, but the technique should be the same for most databases. For Oracle, for example, the only changes would be to use Oracle data access objects, and use ":" in place of "#" in parameter names. The technique for MySQL should also be very similar.
For many databases, shortcuts may exist for creating parameters, such as:
cmd.Parameters.AddWithValue("#start", start);
This works when you know the value is not null, and the correct parameter type can be derived from the C# type of the value. "AddWithValue" is specific to SQL Server; "Add" works also but is obsolete in SQL Server.
Hope this helps.
You can assign format to data time, DateTime.ParseExact() or DateTime.ToString(format), :
the format for 2011-7-27 is yyyy-m-dd
Assuming you are doing this in the database I think you should use date_format to get in the required format
Something like date_format(dateval,'%Y-%c-%d') (Not tested)
I use:
string fieldate = dt1.ToString("yyyy-MM-dd");
i cant insert for using c# language DateTime.Now.ToString()
insert sqlserver in datatype datetime field
Don't convert your DateTime value to a string. Use parameterised SQL instead:
string sql = "INSERT INTO Your_Table (Your_Column) VALUES (#YourParam)";
using (SqlConnection conn = new SqlConnection("..."))
using (SqlCommand cmd = new SqlCommand(sql, conn))
{
cmd.Parameters.Add("#YourParam", SqlDbType.DateTime).Value = yourDate;
conn.Open();
cmd.ExecuteNonQuery();
}
You shouldnt have to perform ToString() in order to insert to an SQL server db
Your question didn't make a lot of sense, but I think you're looking for this:
DateTime.Now.ToString(string format)
That'll format the DateTime in the way you want it to.
Yous really shouldn't be building your SQL queries as strings in the first place, though. You should be using parameters, which allow you to give a C# non-string object rather than a converted string.