mssql - compare two datetime fields

problem
	mssql - compare two datetime Mssql, compare two datetime fields, if their values are close, if are in 24h difference and do on --- > dennis
difficulty level
	1/10 :)))
compatibility
	mssql
solution
	In mssql, the datetime fields are actually numeric with decimals. The integer part in the “days”. So if you want to compare two dates compare the integer part as bellow -- compare if the item is sold 24h before the item is modified Select * from items Where ModificationDate<SaleDate-1 -- find person(s) that born on 12/11/2010 (not exactly on the same, with at least 12 hours difference) Select * from persons Where birthdate-0.5>=’2010-12-11’ and birthdate+0.5<=’2010-12-11’

MSSQL - how to copy tables and data

problem
	MSSQL - how to copy - How to copy a table’s structure to another database? - How to create a table with the same structure (fields) on the - How to copy the data of the table to another table?
difficulty level
	4/10 :)
compatibility
	general
solution
	How to copy a table’s structure to another database? The follow code, not only copy’s the structure but also copies and the records of it. You may filter the data applying a “where” as I do here. --Do like: SELECT * INTO [TargetDatabase].[dbo].[MyTable] FROM [SourceDatabase].[dbo].[MyTable] where [SourceDatabase].[dbo].[MyTable].CustomerCode='01'; -- where is optional How to create a table with the same structure (fields) on the same database? (Like you did previously!) --Do like: SELECT * INTO MyNewTable FROM MySourceTable where MySourceTable.CustomerCode='01'; -- where is optional How to copy the data of the table to another table? --Syntax: INSERT INTO TargetTable( <field list> ) SELECT <field list> FROM SourceTable --Do like: INSERT INTO NewCustomers ( Company, Branch, Name ) SELECT Company, Branch, Name FROM Customers Where Branch=’01’; -- where is optional

String Format for DateTime [C#]

This example shows how to format DateTime using String.Format method. All formatting can be done also using DateTime.ToString method.

Custom DateTime Formatting

There are following custom format specifiers y (year), M (month), d (day), h (hour 12), H (hour 24), m (minute), s (second), f (second fraction), F (second fraction, trailing zeroes are trimmed), t (P.M or A.M) and z (time zone).
Following examples demonstrate how are the format specifiers rewritten to the output.
[C#]

// create date time 2008-03-09 16:05:07.123
DateTime dt = new DateTime(2008, 3, 9, 16, 5, 7, 123);

String.Format("{0:y yy yyy yyyy}", dt);  // "8 08 008 2008"   year
String.Format("{0:M MM MMM MMMM}", dt);  // "3 03 Mar March"  month
String.Format("{0:d dd ddd dddd}", dt);  // "9 09 Sun Sunday" day
String.Format("{0:h hh H HH}",     dt);  // "4 04 16 16"      hour 12/24
String.Format("{0:m mm}",          dt);  // "5 05"            minute
String.Format("{0:s ss}",          dt);  // "7 07"            second
String.Format("{0:f ff fff ffff}", dt);  // "1 12 123 1230"   sec.fraction
String.Format("{0:F FF FFF FFFF}", dt);  // "1 12 123 123"    without zeroes
String.Format("{0:t tt}",          dt);  // "P PM"            A.M. or P.M.
String.Format("{0:z zz zzz}",      dt);  // "-6 -06 -06:00"   time zone

DevExpress, GridControl, how the Best Fit Column feature works

The property GridView.BestFitMaxRowCount indicates how many rows will be processed in order to adjust the best column width.

• -1 means that all row will be processed
• 0 nothing
• Any other value indicates how many will be processed

For performance issues apply a small number or apply 0.

Important note: If auto width is enabled, a column's GridColumn.Width property doesn't contain its visible width, but the value used when auto width is false, so that a column's layout can be restored. A column's visible width is available via its GridColumn.VisibleWidth property.

More at: http://documentation.devexpress.com/#WindowsForms/CustomDocument649

Method code, to convert a deleted DataRow to non deleted DataRow

        /// <summary>
        /// Get the deleted record you provide as non deleted row; NOTE: the State of the row is ADDED.
        /// </summary>
        /// <param name="sourceDataTable"></param>
        /// <param name="deletedDataRow"></param>
        /// <returns></returns>
        public static DataRow readDeletedDataRow(DataTable sourceDataTable,DataRow deletedDataRow) {
            int deletedDataRowIndex = sourceDataTable.Rows.IndexOf(deletedDataRow);
            DataView deletedView = new DataView(sourceDataTable, null, null, DataViewRowState.Deleted);
            DataTable deletedRecordsTable = deletedView.ToTable();
            return deletedRecordsTable.Rows[deletedDataRowIndex];
        }

Accessing deleted row field values from data table with C#.net

Solution #1

          Sometimes we delete data row in data table of dataset. Then we may need again to get deleted row field information from the dataset back for some calculation purpose. It gives error if we want to access the row data from the data table telling "The data row has been deleted ...".

         We can still access the field data information by using DataRowVersion.Original parameter. For example

         int customerId = Convert.ToInt32( DataTable1.Rows[0][0, DataRowVersion.Original];

         This will give the original version of the row data. And voila - we have our original data back.

Solution #2

          We can make a Data View out of the datatable. Then convert that data view into data table again. This will give us the original data. But this time the datarowstate = "added".

          We see one example code for this.

          DataView myView = new DataView(sourceTable, null, null, DataViewRowState.Deleted);
          DataTable myTable = myView.ToTable();

how to add and remove event handers

simple with += and -= operators

/* A Programmer's Introduction to C# (Second Edition)
by Eric Gunnerson Publisher: Apress  L.P.  ISBN: 1-893115-62-3  */
// 23 - Events\Custom Add and Remove --- copyright 2000 Eric Gunnerson

using System;
using System.Collections;
using System.Runtime.CompilerServices;


public class EventsCustomAddandRemove
{
    static public void ButtonHandler(object sender, EventArgs e)
    {
        Console.WriteLine("Button clicked");
    }
    
    public static void Main()
    {
        Button button = new Button();
        
        button.Click += new Button.ClickHandler(ButtonHandler);
        
        button.SimulateClick();
        
        button.Click -= new Button.ClickHandler(ButtonHandler);
        
        button.TearDown();
    }
}