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Insert empty DateTime from C# into FoxPro

I am trying to insert an empty DateTime into a FoxPro database using DbParameter in C#. Our application marries FoxPro data along with SQL Server and .NET models/data.
My current issue is that most of our DateTime types in C# are not nullable, nor should they be. However, most of our legacy data in FoxPro are empty dates (shown as ' / / : : '). I am trying to do an insert into the FoxPro table where I do a check to see if the .NET DateTime meets certain criteria, then inserts an empty date. This last part has proven to be a nightmare.
What I have tried so far:
.Parameters.Add(string.Empty, new DateTime())
The above understandably inserts 01/01/0001 but is not what we want.
.Parameters.Add(string.Empty, "{}")
.Parameters.Add(string.Empty, "{:://}")
.Parameters.Add(string.Empty, "{//}")
.Parameters.Add(string.Empty, "'{}'")
The above all result in
System.Data.OleDb.OleDbException: 'Data type mismatch'.
which makes sense because I'm trying to send a string to a field with DateTime type.
Does anyone know how to insert an empty DateTime into FoxPro?

If I'm understanding you correctly, you're not using a DbParameter, but rather an OleDbParameter, and you're adding them through the OleDbParameterCollection.Add method?
If so, consider that you are using the overload that is .Add(String, Object), and you could instead use the overload that is .Add(String, OleDbType):
.Parameters.Add(string.Empty, OleDbType.Date)
The default value of an OleDbParameter is null, so you don't need to do anything more for your empty dates.
Also, depending on how the column is defined in your FoxPro database schema, it may be appropriate to pass OleDbType.Date, OleDbType.DBDate, OleDbType.DBTime, or OleDbType.DBTimeStamp. The full list of OleDB types is documented here, but I'm not entirely certain how they align to FoxPro's data types.

I believe your second example is close, but you have the Date and Time portions reversed.
It should be .Parameters.Add(string.Empty, "{//::}")
The // represent the Date portion, and the :: the Time portion.

Not sure of your SQL-Insert statement for VFP, but you MAY need to adjust it and do TWO different inserts. One IF a date exists, another if it does not.
For the one that does NOT have a date, I would hard-enter the following (for example where the "?" are the parameter place-holders)
insert into yourTable ( fld1, fld2,..., YourDateField ) values ( ?, ?, ..., ctot('') )
the function CTOT() means character to datetime and an empty string will comply with expected VFP Date/time field.

Work for me.
Parameters.AddWithValue("CreateDate", new DateTime(1899,12,30,0,0,0));

How to get NumericPrecision and Scale of a decimal from DataTable

I need to get the exact type of a column in a DataTable in C#.
In a simliar article on SO i found part of a solution:
DataTable st = reader.GetSchemaTable();
foreach (DataRow row in st.Rows)
{
Console.Write(string.Format("ColumnName:{0} DataType:{1} Ordinal:{2} Precision:{3} Size:{4} Scale:{5}",
row["ColumnName"], row["DataTypeName"], row["ColumnOrdinal"],
row["NumericPrecision"], row["ColumnSize"], row["NumericScale"]));
}
This works for string and date so far.
But for decimal i always recieve nullfor precision and scale.
I need those values to create a new table in another database.
The DataType returned is Decimal.
In the MSDN documentation it says that NumericPrecision returns null if it is no numeric data type, but decimal is kind of numeric?
So how do i get the exact precision of decimal values from the DataSet? Or rather what am I doing wrong?
edit:
I am trying to create some new SQL database based on old .dbf files from a FoxPro application.
So i want to read the columns, and create them in SQL, therefore I need the exact type of the column.
I tried with the .dbf and a new sql database.
I created a table in both to know the exact type for sure, for both databases i get those null returns. There is only a problem with the decimal/numeric values, for string and DateTime i get the Size.
For the .dbf I use a OleDbConnection.
For the SQL I use a SqlConnection, I get null if I try it for each.

From my experience with MySQL, the decimal datatype is numeric, but it can hold any precision or scale. If the database you are trying to create doesn't have the decimal datatype, you may need to convert it to a different type of number and possibly guess what precision and scale you need.

Datetime format is 'mm-dd-yyyy' when getting while using SqlDataAdapter but if I run the same query in ms sql then its 'yyyy-mm-dd'

I know the question is a bit confusing. Please let me elaborate.
Suppose
I have a table student master which has a column DOB
I have inserted a record and in DOB I have inserted '1991-01-01'
running select statement from sql server is returning date in the same format as it is inserted '1991-01-01' but when I am running the same query from C# using SqlDataAdapter then its returning date as '01-01-1991'
Can anyone explain why it is happening and is there any way to fetch the date in same format as it is inserted.
Query
Is it possible to get the DateTime using SqlDataAdapter as it was inserted?
P.S: column data type is Datetime

let's separate the wheat from the chaff :)
if for your needs meaningful is data type (datetime in this case), then formatting does not matter at all. All layers which will exchange or process the data will use data type information for that.
But
if the meaningful part is formatting, i.e. string representation of the data, then you need to consider the appropriate settings of UI tools you use to display your data. SSMS, for example, uses regional settings for that. If you need to visualize data in the identical manner, so you need the identical strings, you should take care of formatting by your self or in another words, you need to convert your datetime data to string in the same way in all places where you need it.
In T-SQL, for example, you could use CAST and CONVERT functions for formatting your data in a format you need.

If you can't match up the "Cultures" between the SQL Server and the machine you're building the application on (and, in fact, you cannot rely on that really if you're application is going to be deployed to other machines!), then the cheap and quick way round it is to run your date returns through a parse function such as this:
private string FncFormatDate(string date)
{
DateTime formattedDate;
if (DateTime.TryParse(date, out formattedDate))
{
return formattedDate.ToString("yyyy-MM-dd");
}
else
{
return "Invalid date";
}
}
I hope this answers your question.

Different format for timestamp when using c# datareader

I'm reading a timestamp from a mysql table using an OdbcDataReader. When I look at the data in the table it is in the format 2013-09-12 11:11:09. But the reader seems to read it in the format 12/09/2013 11:11:09.
I then try to insert this into another mysql table but receive the error:
Incorrect datetime value: '12/09/2013 11:11:09' for column 'timestamp'
at row 1
How can I sort out this difference in formatting? Should I be referencing some Unix timestamp value somehow?

The data shouldn't be in the table in any text format. It's just a date and time.
You'll see the format when you convert the data to a string - which you should do as rarely as possible. In particular, when you're inserting the data into a different table, you shouldn't use a formatted value at all - you should use a DateTime in parameterized SQL.
Basically, unless you really need a string representation of the data, you should keep it in the "native" representation (DateTime in this case). Every time you have a conversion to or from text, that's an opportunity for failure. Dates and times are hard enough with time zones etc, without extraneous conversions getting involved.

How are you looking at the data "in the table"? I'm not familiar with the MySQL implementation, but with Oracle and Sql Server datetime values are stored in an unreadable binary format, and translated to a readable timestamp by the query tool. MySQL is likely doing something similar.
try to insert this into another mysql table
If you care about format when you're inserting the data, you're doing something really bad. That's a strong indication you're using a technique that will be vulnerable to sql injection attacks, rather than parameterized queries. If you use parameterized queries, you assign a C# datetime type to the query parameter value directly, and the ADO.Net object handles any formatting you need. At that point, anything you can successfully DateTime.Parse() or DateTime.TryParse() becomes a valid input for your query.

Preserving SQL DateTime format when reading from database

I have a very simple tool that runs a stored procedure from a database, puts the results into a DataTable, then writes the DataTable to a file via Response. The purpose is to take the data from a table on SQL Server, then use a 3rd-party tool to upload it to an Oracle database.
The problem I encounter is that date is stored, in SQL Server, as such: 2011-05-01 00:00:00.000.
However, when I access it via my SqlDataReader and put it into my DataTable, it ends up formatting as: 5/1/2011 12:00:00 AM.
So I figured I could just explicitly parse it as an OracleDateTime. I have the following column in my DataTable:
records.Columns.Add("Date", typeof(OracleDateTime));
As well as this bit where I am reading the results:
row["Date"] = OracleDateTime.Parse(rdr["Date"].ToString());
I also tried SqlDateTime for kicks, but ultimately, I end up with the same incorrectly formatted string. I just want it to stay the same way SQL returns it in the query - how can this be done?

The date is not stored that way in SQL server; what you see in your ad-hoc queries is a conversion from the internal numeric storage to that format.
When you read it in, you should be converting rdr["Date"] to a DateTime.
If you want that specific format in your code, you should format it using .NET's formatters when you output it.