Excel Jet OLE DB: Inserting a DateTime value

问题

OLEDB can be used to read and write Excel sheets. Consider the following code example:

using (OleDbConnection conn = new OleDbConnection("Provider=Microsoft.Jet.OLEDB.4.0;Data Source=C:\\my\\excel\\file.xls;Extended Properties='Excel 8.0;HDR=Yes'")) {
    conn.Open();
    OleDbCommand cmd = new OleDbCommand("CREATE TABLE [Sheet1] ([Column1] datetime)", conn);
    cmd.ExecuteNonQuery();
    cmd = new OleDbCommand("INSERT INTO Sheet1 VALUES (@mydate)", conn);
    cmd.Parameters.AddWithValue("@mydate", DateTime.Now.Date);
    cmd.ExecuteNonQuery();
}

This works perfectly fine. Inserting numbers, text, etc. also works well. However, inserting a value with a time component fails:

using (OleDbConnection conn = new OleDbConnection("Provider=Microsoft.Jet.OLEDB.4.0;Data Source=C:\\my\\excel\\file.xls;Extended Properties='Excel 8.0;HDR=Yes'")) {
    conn.Open();
    OleDbCommand cmd = new OleDbCommand("CREATE TABLE [Sheet1] ([Column1] datetime)", conn);
    cmd.ExecuteNonQuery();
    cmd = new OleDbCommand("INSERT INTO Sheet1 VALUES (@mydate)", conn);
    cmd.Parameters.AddWithValue("@mydate", DateTime.Now); // <-- note the difference here
    cmd.ExecuteNonQuery();
}

Executing this INSERT fails with an OleDbException: Data type mismatch in criteria expression.

Is this a known bug? If yes, what can be done to workaround it? I've found one workaround that works:

cmd = new OleDbCommand(String.Format(@"INSERT INTO Sheet1 VALUES (#{0:dd\/MM\/yyyy HH:mm:ss}#)", DateTime.Now), conn);

It basically creates an SQL statement that looks like this: INSERT INTO Sheet1 VALUES (#05/29/2011 13:12:01#). Of course, I don't have to tell you how ugly this is. I'd much rather have a solution with a parameterized query.

回答1:

It appears to be a known bug https://connect.microsoft.com/VisualStudio/feedback/details/94377/oledbparameter-with-dbtype-datetime-throws-data-type-mismatch-in-criteria-expression

You might want to truncate the milisecond like this it appear to work for OleDbParameter:

DateTime org = DateTime.UtcNow;
DateTime truncatedDateTime = new DateTime(org.Year, org.Month, org.Day, org.Hour, org.Minute, org.Second);

And add this instead of the DateTime.Now into your parameter value.

回答2:

The problem is the cell containing datetime value cannot be directly put into excel' column. You have to either insert the date component or the time component. The reason for failure is the default property of excel' cell is "values" instead of "datetime" in excel.

来源：https://stackoverflow.com/questions/6253906/excel-jet-ole-db-inserting-a-datetime-value

标签

.net

excel

oledb

jet