Why do I get 80040E10 errors?

When creating SQL statements in ASP, you might encounter one of the following errors: 
 

Microsoft JET Database Engine (0x80040E10)  No value given for one or more required parameters.    or    Microsoft OLE DB Provider for ODBC Drivers error '80040e10'  [Microsoft][ODBC Microsoft Access Driver] Too few parameters. Expected <n>.    or    Microsoft OLE DB Provider for SQL Server error '80040e10'  Procedure '<procedure>' expects parameter '<param>', which was not supplied.

 
This error is due to one of the following things: 

1. A field name was spelled incorrectly.
2. One or more of the values was blank.
3. You tried to insert the wrong datatype (e.g. surrounded a numeric value with quotes, or forgot to put quotes around a string).

To troubleshoot this, response.write your SQL statement: 
 

<%      sql = "EXEC proc_name @param1='foo', ..."      ' instead of conn.execute(sql)      Response.Write(sql)      Response.End  %>

 
Make sure there is data for all params you are passing, and compare column names directly with those in the table. 
 
You can also use this response.write method to copy the SQL statement and execute it directly in the database, if the error message and the response.write statement aren't already giving you enough information. 
 
If parameters to a stored procedure should be optional, then use the following syntax: 
 

CREATE PROCEDURE dbo.proc_name      @param1 INT = NULL  ...

 
(For a bit more detail, see Article #2348.)