phattrienweb

public class clsEmployee

Creating a SqlCommand Object

Similar to other C# objects, you instantiate a SqlCommand object via the new instance declaration, as follows:

SqlCommand cmd = new SqlCommand("select CategoryName from Categories", conn);

The line above is typical for instantiating a SqlCommand object. It takes a string parameter that holds the command you want to execute and a reference to a SqlConnection object. SqlCommand has a few overloads, which you will see in the examples of this tutorial.

Querying Data

When using a SQL select command, you retrieve a data set for viewing. To accomplish this with a SqlCommand object, you would use the ExecuteReader method, which returns a SqlDataReader object. We'll discuss the SqlDataReader in a future lesson. The example below shows how to use the SqlCommand object to obtain a SqlDataReader object:

// 1. Instantiate a new command with a query and connection
SqlCommand cmd = new SqlCommand("select CategoryName from Categories", conn);

// 2. Call Execute reader to get query results
SqlDataReader rdr = cmd.ExecuteReader();

In the example above, we instantiate a SqlCommand object, passing the command string and connection object to the constructor. Then we obtain a SqlDataReader object by calling the ExecuteReader method of the SqlCommand object, cmd.

This code is part of the ReadData method of Listing 1 in the Putting it All Together section later in this lesson.

Inserting Data

To insert data into a database, use the ExecuteNonQuery method of the SqlCommand object. The following code shows how to insert data into a database table:

// prepare command string
string insertString = @"
insert into Categories
(CategoryName, Description)
values ('Miscellaneous', 'Whatever doesn''t fit elsewhere')";

// 1. Instantiate a new command with a query and connection
SqlCommand cmd = new SqlCommand(insertString, conn);

// 2. Call ExecuteNonQuery to send command
cmd.ExecuteNonQuery();

The SqlCommand instantiation is just a little different from what you've seen before, but it is basically the same. Instead of a literal string as the first parameter of the SqlCommand constructor, we are using a variable, insertString. The insertString variable is declared just above the SqlCommand declaration.

Notice the two apostrophes ('') in the insertString text for the word "doesn''t". This is how you escape the apostrophe to get the string to populate column properly.

Another observation to make about the insert command is that we explicitly specified the columns CategoryName and Description. The Categories table has a primary key field named CategoryID. We left this out of the list because SQL Server will add this field itself. trying to add a value to a primary key field, such as CategoryID, will generate an exception.

To execute this command, we simply call the ExecuteNonQuery method on the SqlCommand instance, cmd.

This code is part of the Insertdata method of Listing 1 in the Putting it All Together section later in this lesson.

Updating Data

The ExecuteNonQuery method is also used for updating data. The following code shows how to update data:

// prepare command string
string updateString = @"
update Categories
set CategoryName = 'Other'
where CategoryName = 'Miscellaneous'";

// 1. Instantiate a new command with command text only
SqlCommand cmd = new SqlCommand(updateString);

// 2. Set the Connection property
cmd.Connection = conn;

// 3. Call ExecuteNonQuery to send command
cmd.ExecuteNonQuery();

Again, we put the SQL command into a string variable, but this time we used a different SqlCommand constructor that takes only the command. In step 2, we assign the SqlConnection object, conn, to the Connection property of the SqlCommand object, cmd.

This could have been done with the same constructor used for the insert command, with two parameters. It demonstrates that you can change the connection object assigned to a command at any time.

The ExecuteNonQuery method performs the update command.

This code is part of the UpdateData method of Listing 1 in the Putting it All Together section later in this lesson.

Deleting Data

You can also delete data using the ExecuteNonQuery method. The following example shows how to delete a record from a database with the ExecuteNonQuery method:

// prepare command string
string deleteString = @"
delete from Categories
where CategoryName = 'Other'";

// 1. Instantiate a new command
SqlCommand cmd = new SqlCommand();

// 2. Set the CommandText property
cmd.CommandText = deleteString;

// 3. Set the Connection property
cmd.Connection = conn;

// 4. Call ExecuteNonQuery to send command
cmd.ExecuteNonQuery();

This example uses the SqlCommand constructor with no parameters. Instead, it explicity sets the CommandText and Connection properties of the SqlCommand object, cmd.

We could have also used either of the two previous SqlCommand constructor overloads, used for the insert or update command, with the same result. This demonstrates that you can change both the command text and the connection object at any time.

The ExecuteNonQuery method call sends the command to the database.

This code is part of the DeleteData method of Listing 1 in the Putting it All Together section later in this lesson.

Getting Single values

Sometimes all you need from a database is a single value, which could be a count, sum, average, or other aggregated value from a data set. Performing an ExecuteReader and calculating the result in your code is not the most efficient way to do this. The best choice is to let the database perform the work and return just the single value you need. The following example shows how to do this with the ExecuteScalar method:

// 1. Instantiate a new command
SqlCommand cmd = new SqlCommand("select count(*) from Categories", conn);

// 2. Call ExecuteNonQuery to send command
int count = (int)cmd.ExecuteScalar();

The query in the SqlCommand constructor obtains the count of all records from the Categories table. This query will only return a single value. The ExecuteScalar method in step 2 returns this value. Since the return type of ExecuteScalar is type object, we use a cast operator to convert the value to int.

This code is part of the GetNumberOfRecords method of Listing 1 in the Putting it All Together section later in this lesson.

Putting it All Together

For simplicity, we showed snippets of code in previous sections to demonstrate the applicable techniques . It is also useful to have an entire code listing to see how this code is used in a working program. Listing 1 shows all of the code used in this example, along with a driver in the Main method to produce formatted output.

Listing 1. SqlConnection Demo

using System;
using System.Data;
using System.Data.SqlClient;

///

/// Demonstrates how to work with SqlCommand objects
///

class SqlCommandDemo
{
SqlConnection conn;

public SqlCommandDemo()
{
// Instantiate the connection
conn = new SqlConnection(
"Data Source=(local);Initial Catalog=Northwind;Integrated Security=SSPI");
}

// call methods that demo SqlCommand capabilities
static void Main()
{
SqlCommandDemo scd = new SqlCommandDemo();

Console.WriteLine();
Console.WriteLine("Categories Before Insert");
Console.WriteLine("------------------------");

// use ExecuteReader method
scd.ReadData();

// use ExecuteNonQuery method for Insert
scd.Insertdata();
Console.WriteLine();
Console.WriteLine("Categories After Insert");
Console.WriteLine("------------------------------");

scd.ReadData();

// use ExecuteNonQuery method for Update
scd.UpdateData();

Console.WriteLine();
Console.WriteLine("Categories After Update");
Console.WriteLine("------------------------------");

scd.ReadData();

// use ExecuteNonQuery method for Delete
scd.DeleteData();

Console.WriteLine();
Console.WriteLine("Categories After Delete");
Console.WriteLine("------------------------------");

scd.ReadData();

// use ExecuteScalar method
int numberOfRecords = scd.GetNumberOfRecords();

Console.WriteLine();
Console.WriteLine("Number of Records: {0}", numberOfRecords);
}

///

/// use ExecuteReader method
///

public void ReadData()
{
SqlDataReader rdr = null;

try
{
// Open the connection
conn.Open();

// 1. Instantiate a new command with a query and connection
SqlCommand cmd = new SqlCommand("select CategoryName from Categories", conn);

// 2. Call Execute reader to get query results
rdr = cmd.ExecuteReader();

// print the CategoryName of each record
while (rdr.Read())
{
Console.WriteLine(rdr[0]);
}
}
finally
{
// close the reader
if (rdr != null)
{
rdr.Close();
}

// Close the connection
if (conn != null)
{
conn.Close();
}
}
}

///

/// use ExecuteNonQuery method for Insert
///

public void Insertdata()
{
try
{
// Open the connection
conn.Open();

// prepare command string
string insertString = @"
insert into Categories
(CategoryName, Description)
values ('Miscellaneous', 'Whatever doesn''t fit elsewhere')";

// 1. Instantiate a new command with a query and connection
SqlCommand cmd = new SqlCommand(insertString, conn);

// 2. Call ExecuteNonQuery to send command
cmd.ExecuteNonQuery();
}
finally
{
// Close the connection
if (conn != null)
{
conn.Close();
}
}
}

///

/// use ExecuteNonQuery method for Update
///

public void UpdateData()
{
try
{
// Open the connection
conn.Open();

// prepare command string
string updateString = @"
update Categories
set CategoryName = 'Other'
where CategoryName = 'Miscellaneous'";

// 1. Instantiate a new command with command text only
SqlCommand cmd = new SqlCommand(updateString);

// 2. Set the Connection property
cmd.Connection = conn;

// 3. Call ExecuteNonQuery to send command
cmd.ExecuteNonQuery();
}
finally
{
// Close the connection
if (conn != null)
{
conn.Close();
}
}
}

///

/// use ExecuteNonQuery method for Delete
///

public void DeleteData()
{
try
{
// Open the connection
conn.Open();

// prepare command string
string deleteString = @"
delete from Categories
where CategoryName = 'Other'";

// 1. Instantiate a new command
SqlCommand cmd = new SqlCommand();

// 2. Set the CommandText property
cmd.CommandText = deleteString;

// 3. Set the Connection property
cmd.Connection = conn;

// 4. Call ExecuteNonQuery to send command
cmd.ExecuteNonQuery();
}
finally
{
// Close the connection
if (conn != null)
{
conn.Close();
}
}
}

///

/// use ExecuteScalar method
///

/// number of records
public int GetNumberOfRecords()
{
int count = -1;

try
{
// Open the connection
conn.Open();

// 1. Instantiate a new command
SqlCommand cmd = new SqlCommand("select count(*) from Categories", conn);

// 2. Call ExecuteScalar to send command
count = (int)cmd.ExecuteScalar();
}
finally
{
// Close the connection
if (conn != null)
{
conn.Close();
}
}
return count;
}
}

In Listing 1, the SqlConnection object is instantiated in the SqlCommandDemo structure. This is okay because the object itself will be cleaned up when the CLR garbage collector executes. What is important is that we close the connection when we are done using it. This program opens the connection in a try block and closes it in a finally block in each method.

The ReadData method displays the contents of the CategoryName column of the Categories table. We use it several times in the Main method to show the current status of the Categories table, which changes after each of the insert, update, and delete commands. Because of this, it is convenient to reuse to show you the effects after each method call.

Summary

A SqlCommand object allows you to query and send commands to a database. It has methods that are specialized for different commands. The ExecuteReader method returns a SqlDataReader object for viewing the results of a select query. For insert, update, and delete SQL commands, you use the ExecuteNonQuery method. If you only need a single aggregate value from a query, the ExecuteScalar is the best choice.

I hope you enjoyed this lesson and welcome you to the next one in this series, Lesson 04: Reading Data with the SqlDataReader.

SqlConnection firstConnection = new SqlConnection(connectionString);
firstConnection.Open();

SqlConnection secondConnection = new SqlConnection(connectionString);
secondConnection.Open();

try
{
  using (SqlCommand firstCommand = new SqlCommand(firstQuery, firstConnection))
  {
    ...
    using (SqlDataReader firstReader = firstCommand.ExecuteReader())
    {
      while (firstReader.Read())
      {
        ...
        using (SqlCommand secondCommand = new SqlCommand(secondQuery, secondConnection))
        {
          ...
          using (SqlDataReader secondReader = secondCommand.ExecuteReader())
          {
            while (secondReader.Read())
            {
              ...
            }
          }
        }
      }
    }
  }
}
catch (Exception ex)
{
  ...
}

firstConnection.Close();
secondConnection.Close();

protected void Page_Load(object sender, EventArgs e)
{
if (!IsPostBack)
{
populateRootNode();
}
}
//Call the function with null argument

protected DataSet PDataset(string select_statement)
{
SqlConnection _con = new SqlConnection(connStr);
SqlDataAdapter ad = new SqlDataAdapter(select_statement, _con);
DataSet ds = new DataSet();
ad.Fill(ds);
_con.Close();
return ds;
}


private void populateRootNode()
{
SqlConnection con = new SqlConnection(connStr);
string sql = "select FoodCategoryID,FoodCategoryName,(select count(*) FROM FoodCategories WHERE ParentID=sc.FoodCategoryID) childnodecount FROM FoodCategories sc where ParentID IS NULL";
SqlDataAdapter da = new SqlDataAdapter(sql, con);
DataTable dt = new DataTable();
string sql2 = "select FoodPackID,FoodPackName,(select count(*) FROM FoodPacks WHERE CategoryID=cat.FoodCategoryID) childnodecount FROM FoodPacks sc left join FoodCategories cat on cat.FoodCategoryID = sc.CategoryID";
SqlDataAdapter da2 = new SqlDataAdapter(sql2, con);
DataTable dt2 = new DataTable();

da.Fill(dt);
populateNode(dt, TreeView1.Nodes); //Function used to fill Populate the tree nodes.
//populateNode2(dt2, TreeView1.Nodes); //Function used to fill Populate the tree nodes.
}
private void populateNode(DataTable dt, TreeNodeCollection node)
{
int parentId;
foreach (DataRow dr in dt.Rows)
{
TreeNode tn = new TreeNode();
string nodeid = dr["FoodCategoryID"].ToString();
string addnew = "Thêm mới";
//tn.Text = dr["FoodCategoryName"].ToString();
int subnode = int.Parse(dr["childnodecount"].ToString().Trim());
tn.Text = dr["FoodCategoryName"].ToString() + " (" + subnode + ")";
tn.Value = dr["FoodCategoryName"].ToString();
tn.NavigateUrl = tn.Text;
parentId = Convert.ToInt32(dr["FoodCategoryID"]);
node.Add(tn);
populatesublevel(parentId, tn);
//populatesublevel2(parentId, tn);
}
}
private void populatesublevel(int parentId, TreeNode parentNode)
{
SqlConnection con = new SqlConnection(connStr);
string sql = "select FoodCategoryID,FoodCategoryName,(select count(*) FROM FoodCategories WHERE ParentID=sc.FoodCategoryID) childnodecount FROM FoodCategories sc where ParentID=@parentID";
SqlDataAdapter da = new SqlDataAdapter(sql, con);
da.SelectCommand.Parameters.AddWithValue("@parentID", parentId);
DataTable dt = new DataTable();
da.Fill(dt);
populateNode(dt, parentNode.ChildNodes);
}

It woking very goo :)

see link http://shivasoft.in/blog/sql/get-first-day-and-last-day-of-week-sql-server/

Execute the following Microsoft SQL Server T-SQL datetime, date and time formatting scripts in Management Studio Query Editor to demonstrate the usage of the multitude of temporal data formats available and the application of date / datetime functions.

-- SQL Server T-SQL date and datetime formats - sql date / datetime format
-- Date time formats - mssql datetime - sql server date formats - sql dates format
-- MSSQL getdate returns current system date and time in standard internal format
-- SQL datetime formats with century (YYYY or CCYY format)- sql time format

SELECT convert(varchar, getdate(), 100) -- mon dd yyyy hh:mmAM (or PM)

-- Oct 2 2010 11:01AM

SELECT convert(varchar, getdate(), 101) -- mm/dd/yyyy - 10/02/2010

SELECT convert(varchar, getdate(), 102) -- yyyy.mm.dd - 2010.10.02

SELECT convert(varchar, getdate(), 103) -- dd/mm/yyyy

SELECT convert(varchar, getdate(), 104) -- dd.mm.yyyy

SELECT convert(varchar, getdate(), 105) -- dd-mm-yyyy

SELECT convert(varchar, getdate(), 106) -- dd mon yyyy

SELECT convert(varchar, getdate(), 107) -- mon dd, yyyy

SELECT convert(varchar, getdate(), 108) -- hh:mm:ss

SELECT convert(varchar, getdate(), 109) -- mon dd yyyy hh:mm:ss:mmmAM (or PM)

-- Oct 2 2010 11:02:44:013AM

SELECT convert(varchar, getdate(), 110) -- mm-dd-yyyy

SELECT convert(varchar, getdate(), 111) -- yyyy/mm/dd

-- yyyymmdd - ISO date format - international standard - works with any language setting

SELECT convert(varchar, getdate(), 112) -- yyyymmdd

SELECT convert(varchar, getdate(), 113) -- dd mon yyyy hh:mm:ss:mmm

-- 02 Oct 2010 11:02:07:577

SELECT convert(varchar, getdate(), 114) -- hh:mm:ss:mmm(24h)

SELECT convert(varchar, getdate(), 120) -- yyyy-mm-dd hh:mm:ss(24h)

SELECT convert(varchar, getdate(), 121) -- yyyy-mm-dd hh:mm:ss.mmm

SELECT convert(varchar, getdate(), 126) -- yyyy-mm-ddThh:mm:ss.mmm

-- 2010-10-02T10:52:47.513

-- Without century (YY) date / datetime conversion - there are exceptions!

SELECT convert(varchar, getdate(), 0) -- mon dd yyyy hh:mmAM (or PM)

SELECT convert(varchar, getdate(), 1) -- mm/dd/yy

SELECT convert(varchar, getdate(), 2) -- yy.mm.dd

SELECT convert(varchar, getdate(), 3) -- dd/mm/yy

SELECT convert(varchar, getdate(), 4) -- dd.mm.yy

SELECT convert(varchar, getdate(), 5) -- dd-mm-yy

SELECT convert(varchar, getdate(), 6) -- dd mon yy

SELECT convert(varchar, getdate(), 7) -- mon dd, yy

SELECT convert(varchar, getdate(), 8) -- hh:mm:ss

SELECT convert(varchar, getdate(), 9) -- mon dd yyyy hh:mm:ss:mmmAM (or PM)

SELECT convert(varchar, getdate(), 10) -- mm-dd-yy

SELECT convert(varchar, getdate(), 11) -- yy/mm/dd

SELECT convert(varchar, getdate(), 12) -- yymmdd

SELECT convert(varchar, getdate(), 13) -- dd mon yyyy hh:mm:ss:mmm

SELECT convert(varchar, getdate(), 14) -- hh:mm:ss:mmm(24h)

SELECT convert(varchar, getdate(), 20) -- yyyy-mm-dd hh:mm:ss(24h)

SELECT convert(varchar, getdate(), 21) -- yyyy-mm-dd hh:mm:ss.mmm

SELECT convert(varchar, getdate(), 22) -- mm/dd/yy hh:mm:ss AM (or PM)

SELECT convert(varchar, getdate(), 23) -- yyyy-mm-dd

SELECT convert(varchar, getdate(), 24) -- hh:mm:ss

SELECT convert(varchar, getdate(), 25) -- yyyy-mm-dd hh:mm:ss.mmm

-- SQL create different date styles with t-sql string functions

SELECT replace(convert(varchar, getdate(), 111), '/', ' ') -- yyyy mm dd

SELECT convert(varchar(7), getdate(), 126) -- yyyy-mm

SELECT right(convert(varchar, getdate(), 106), 8) -- mon yyyy
SELECT substring(convert(varchar, getdate(), 120),6, 11) -- mm-dd hh:mm

------------

-- SQL Server date formatting function - convert datetime to string

------------

-- SQL datetime functions - SQL date functions - SQL datetime formatting

-- SQL Server date formats - sql server date datetime - sql date formatting

-- T-SQL convert dates - T-SQL date formats - Transact-SQL date formats

-- Formatting dates sql server - sql convert datetime format

CREATE FUNCTION dbo.fnFormatDate (@Datetime DATETIME, @FormatMask VARCHAR(32))

RETURNS VARCHAR(32)

AS

BEGIN

DECLARE @StringDate VARCHAR(32)

SET @StringDate = @FormatMask

IF (CHARINDEX ('YYYY',@StringDate) > 0)

SET @StringDate = REPLACE(@StringDate, 'YYYY', DATENAME(YY, @Datetime))

IF (CHARINDEX ('YY',@StringDate) > 0)

SET @StringDate = REPLACE(@StringDate, 'YY', RIGHT(DATENAME(YY, @Datetime),2))

IF (CHARINDEX ('Month',@StringDate) > 0)

SET @StringDate = REPLACE(@StringDate, 'Month', DATENAME(MM, @Datetime))

IF (CHARINDEX ('MON',@StringDate COLLATE SQL_Latin1_General_CP1_CS_AS)>0)

SET @StringDate = REPLACE(@StringDate, 'MON',

LEFT(UPPER(DATENAME(MM, @Datetime)),3))

IF (CHARINDEX ('Mon',@StringDate) > 0)

SET @StringDate = REPLACE(@StringDate, 'Mon', LEFT(DATENAME(MM, @Datetime),3))

IF (CHARINDEX ('MM',@StringDate) > 0)

SET @StringDate = REPLACE(@StringDate, 'MM',

RIGHT('0'+CONVERT(VARCHAR,DATEPART(MM, @Datetime)),2))

IF (CHARINDEX ('M',@StringDate) > 0)

SET @StringDate = REPLACE(@StringDate, 'M',

CONVERT(VARCHAR,DATEPART(MM, @Datetime)))

IF (CHARINDEX ('DD',@StringDate) > 0)

SET @StringDate = REPLACE(@StringDate, 'DD',

RIGHT('0'+DATENAME(DD, @Datetime),2))

IF (CHARINDEX ('D',@StringDate) > 0)

SET @StringDate = REPLACE(@StringDate, 'D', DATENAME(DD, @Datetime))

RETURN @StringDate

END

GO

-- Microsoft SQL Server date format function test

-- MSSQL formatting dates - sql datetime date

SELECT dbo.fnFormatDate (getdate(), 'MM/DD/YYYY') -- 01/03/2012

SELECT dbo.fnFormatDate (getdate(), 'DD/MM/YYYY') -- 03/01/2012

SELECT dbo.fnFormatDate (getdate(), 'M/DD/YYYY') -- 1/03/2012

SELECT dbo.fnFormatDate (getdate(), 'M/D/YYYY') -- 1/3/2012

SELECT dbo.fnFormatDate (getdate(), 'M/D/YY') -- 1/3/12

SELECT dbo.fnFormatDate (getdate(), 'MM/DD/YY') -- 01/03/12

SELECT dbo.fnFormatDate (getdate(), 'MON DD, YYYY') -- JAN 03, 2012

SELECT dbo.fnFormatDate (getdate(), 'Mon DD, YYYY') -- Jan 03, 2012

SELECT dbo.fnFormatDate (getdate(), 'Month DD, YYYY') -- January 03, 2012

SELECT dbo.fnFormatDate (getdate(), 'YYYY/MM/DD') -- 2012/01/03

SELECT dbo.fnFormatDate (getdate(), 'YYYYMMDD') -- 20120103

SELECT dbo.fnFormatDate (getdate(), 'YYYY-MM-DD') -- 2012-01-03

-- CURRENT_TIMESTAMP returns current system date and time in standard internal format

SELECT dbo.fnFormatDate (CURRENT_TIMESTAMP,'YY.MM.DD') -- 12.01.03

GO

------------

/***** SELECTED SQL DATE/DATETIME FORMATS WITH NAMES *****/

-- SQL format datetime - - sql hh mm ss - sql yyyy mm dd

-- Default format: Oct 23 2006 10:40AM

SELECT [Default]=CONVERT(varchar,GETDATE(),100)

-- US-Style format: 10/23/2006

SELECT [US-Style]=CONVERT(char,GETDATE(),101)

-- ANSI format: 2006.10.23

SELECT [ANSI]=CONVERT(char,CURRENT_TIMESTAMP,102)

-- UK-Style format: 23/10/2006

SELECT [UK-Style]=CONVERT(char,GETDATE(),103)

-- German format: 23.10.2006

SELECT [German]=CONVERT(varchar,GETDATE(),104)

-- ISO format: 20061023

SELECT ISO=CONVERT(varchar,GETDATE(),112)

-- ISO8601 format: 2010-10-23T19:20:16.003

SELECT [ISO8601]=CONVERT(varchar,GETDATE(),126)

------------

-- SQL Server datetime formats - Format dates SQL Server 2005 / 2008
-- Century date format MM/DD/YYYY usage in a query

SELECT TOP (1)

SalesOrderID,

OrderDate = CONVERT(char(10), OrderDate, 101),

OrderDateTime = OrderDate

FROM AdventureWorks.Sales.SalesOrderHeader

/*

SalesOrderID OrderDate OrderDateTime

43697 07/01/2001 2001-07-01 00:00:00.000

*/

-- SQL update datetime column - SQL datetime DATEADD - datetime function

UPDATE Production.Product

SET ModifiedDate=DATEADD(dd,1, ModifiedDate)

WHERE ProductID = 1001

-- MM/DD/YY date format - Datetime format sql

SELECT TOP (1)

SalesOrderID,

OrderDate = CONVERT(varchar(8), OrderDate, 1),

OrderDateTime = OrderDate

FROM AdventureWorks.Sales.SalesOrderHeader

ORDER BY SalesOrderID desc

/*

SalesOrderID OrderDate OrderDateTime

75123 07/31/04 2004-07-31 00:00:00.000

*/

------------

-- SQL convert datetime to char - sql date string concatenation: + (plus) operator

PRINT 'Style 110: '+CONVERT(CHAR(10),GETDATE(),110) -- Style 110: 07-10-2012

PRINT 'Style 111: '+CONVERT(CHAR(10),GETDATE(),111) -- Style 111: 2012/07/10

PRINT 'Style 112: '+CONVERT(CHAR(8), GETDATE(),112) -- Style 112: 20120710

------------

-- Combining different style formats for date & time

-- Datetime formats - sql times format - datetime formats sql

DECLARE @Date DATETIME

SET @Date = '2015-12-22 03:51 PM'

SELECT CONVERT(CHAR(10),@Date,110) + SUBSTRING(CONVERT(varchar,@Date,0),12,8)

-- Result: 12-22-2015 3:51PM

-- Microsoft SQL Server cast datetime to string

SELECT stringDateTime=CAST (getdate() as varchar)

-- Result: Dec 29 2012 3:47AM

Related article: SQL Server DateTime Formatting

------------

-- SQL Server date and time functions overview

------------

-- SQL Server CURRENT_TIMESTAMP function - SQL Server datetime functions

-- Local NYC - EST - Eastern Standard Time zone

-- SQL DATEADD function - SQL DATEDIFF function

SELECT CURRENT_TIMESTAMP -- 2012-01-05 07:02:10.577

-- SQL Server DATEADD function

SELECT DATEADD(month,2,'2012-12-09') -- 2013-02-09 00:00:00.000

-- SQL Server DATEDIFF function

SELECT DATEDIFF(day,'2012-12-09','2013-02-09') -- 62

-- SQL Server DATENAME function

SELECT DATENAME(month, '2012-12-09') -- December

SELECT DATENAME(weekday, '2012-12-09') -- Sunday

-- SQL Server DATEPART function

SELECT DATEPART(month, '2012-12-09') -- 12

-- SQL Server DAY function

SELECT DAY('2012-12-09') -- 9

-- SQL Server GETDATE function

-- local NYC - EST - Eastern Standard Time zone

SELECT GETDATE() -- 2012-01-05 07:02:10.577

-- SQL Server GETUTCDATE function

-- London - Greenwich Mean Time

SELECT GETUTCDATE() -- 2012-01-05 12:02:10.577

-- SQL Server MONTH function

SELECT MONTH('2012-12-09') -- 12

-- SQL Server YEAR function

SELECT YEAR('2012-12-09') -- 2012

------------

-- Universal CONVERT function - datetime conversion UDF

------------

CREATE FUNCTION fnCONVERT( @Input datetimeoffset, @StyleNo int)

RETURNS nvarchar(35) AS

BEGIN

RETURN (CONVERT(nvarchar(35), @Input, @StyleNo))

END

GO

DECLARE @dt DATE=getdate(); SELECT dbo.fnCONVERT( @dt,106) -- 23 Dec 2010

GO

DECLARE @dt DATE=getdate(); SELECT dbo.fnCONVERT( @dt,156) -- 23 Dec 2010

GO

/* Msg 281, Level 16, State 1, Line 1

156 is not a valid style number when converting from datetimeoffset

to a character string. */

DECLARE @dt DATETIME=getdate(); SELECT dbo.fnCONVERT( @dt,112) -- 20101223

GO

DECLARE @dt SMALLDATETIME=getdate(); SELECT dbo.fnCONVERT( @dt,101) -- 12/23/2010

GO

------------

------------

-- SQL calculate the number of business days function - exclude Saturdays & Sundays

------------

CREATE FUNCTION fnBusinessDaysCount (@StartDate DATE, @EndDate DATE)

RETURNS INT AS

BEGIN

IF (@StartDate IS NULL OR @EndDate IS NULL) RETURN (0)

DECLARE @i INT = 0;

WHILE (@StartDate <= @EndDate)

BEGIN

SET @i = @i + CASE

WHEN datepart(dw,@StartDate) BETWEEN 2 AND 6 THEN 1

ELSE 0

END

SET @StartDate = DATEADD(dd,1,@StartDate)

END -- while

RETURN (@i)

END -- function

GO

SELECT dbo.fnBusinessDaysCount('2016-01-01','2016-12-31')

-- 261

------------

------------

-- T-SQL Date and time function application

-- CURRENT_TIMESTAMP and getdate() are the same in T-SQL

------------

-- T-SQL first day of week and last day of week

SELECT FirstDateOfWeek = dateadd(dd,-DATEPART(dw,GETDATE()) + 1,GETDATE())

SELECT LastDateOfWeek = dateadd(dd,7 - DATEPART(dw,GETDATE()),GETDATE())

-- SQL first day of the month - SQL first date of the month

-- SQL first day of current month - 2012-01-01 00:00:00.000

SELECT DATEADD(dd,0,DATEADD(mm, DATEDIFF(mm,0,CURRENT_TIMESTAMP),0))

-- SQL last day of the month - SQL last date of the month

-- SQL last day of current month - 2012-01-31 00:00:00.000

SELECT DATEADD(dd,-1,DATEADD(mm, DATEDIFF(mm,0,CURRENT_TIMESTAMP)+1,0))

-- SQL first day of last month

-- SQL first day of previous month - 2011-12-01 00:00:00.000

SELECT DATEADD(mm,-1,DATEADD(mm, DATEDIFF(mm,0,CURRENT_TIMESTAMP),0))

-- SQL last day of last month

-- SQL last day of previous month - 2011-12-31 00:00:00.000

SELECT DATEADD(dd,-1,DATEADD(mm, DATEDIFF(mm,0,DATEADD(MM,-1,GETDATE()))+1,0))

-- SQL first day of next month - 2012-02-01 00:00:00.000

SELECT DATEADD(mm,1,DATEADD(mm, DATEDIFF(mm,0,CURRENT_TIMESTAMP),0))

-- SQL last day of next month - 2012-02-28 00:00:00.000

SELECT DATEADD(dd,-1,DATEADD(mm, DATEDIFF(mm,0,DATEADD(MM,1,GETDATE()))+1,0))

GO

-- SQL first day of a month - 2012-10-01 00:00:00.000

DECLARE @Date datetime; SET @Date = '2012-10-23'

SELECT DATEADD(dd,0,DATEADD(mm, DATEDIFF(mm,0,@Date),0))

GO

-- SQL last day of a month - 2012-03-31 00:00:00.000

DECLARE @Date datetime; SET @Date = '2012-03-15'

SELECT DATEADD(dd,-1,DATEADD(mm, DATEDIFF(mm,0,@Date)+1,0))
GO

-- SQL first day of year - SQL first day of the year - 2012-01-01 00:00:00.000

SELECT DATEADD(yy, DATEDIFF(yy,0,CURRENT_TIMESTAMP), 0)

-- SQL last day of year - SQL last day of the year - 2012-12-31 00:00:00.000

SELECT DATEADD(yy,1, DATEADD(dd, -1, DATEADD(yy,

DATEDIFF(yy,0,CURRENT_TIMESTAMP), 0)))

-- SQL last day of last year - SQL last day of previous year - 2011-12-31 00:00:00.000

SELECT DATEADD(dd,-1,DATEADD(yy,DATEDIFF(yy,0,CURRENT_TIMESTAMP), 0))
GO

------------

-- First and last day of date periods

DECLARE @Date DATETIME; SET = @Date = '20161023';

SELECT ReferenceDate = @Date

SELECT FirstDayOfYear = DATEADD(YY, DATEDIFF(YY,0, @Date),0)

SELECT LastDayOfYear = DATEADD(YY, DATEDIFF(YY,0, @Date)+1,-1)

SELECT FirstDayOfSemester = DATEADD(QQ,((DATEDIFF(QQ,0,@Date)/2)*2),0)

SELECT LastDayOfSemester = DATEADD(QQ,((DATEDIFF(QQ,0,@Date)/2)*2)+2,-1)

SELECT FirstDayOfQuarter = DATEADD(QQ, DATEDIFF(QQ,0, @Date),0)

-- 2016-10-01 00:00:00.000

SELECT LastDayOfQuarter = DATEADD(QQ, DATEDIFF(QQ,0, @Date)+1,-1)

-- 2016-12-31 00:00:00.000

SELECT FirstDayOfMonth = DATEADD(MM, DATEDIFF(MM,0, @Date),0)

SELECT LastDayOfMonth = DATEADD(MM, DATEDIFF(MM,0, @Date)+1,-1)

SELECT FirstDayOfWeek = DATEADD(WK, DATEDIFF(WK,0, @Date),0)

SELECT LastDayOfWeek = DATEADD(WK, DATEDIFF(WK,0, @Date)+1,-1)

-- 2016-10-30 00:00:00.000

------------

-- SQL calculate age in years, months, days - Format dates SQL Server 2008

-- SQL table-valued function - SQL user-defined function - UDF

-- SQL Server age calculation - date difference

USE AdventureWorks2008;

GO

CREATE FUNCTION fnAge (@BirthDate DATETIME)

RETURNS @Age TABLE(Years INT,

Months INT,

Days INT)

AS

BEGIN

DECLARE @EndDate DATETIME, @Anniversary DATETIME

SET @EndDate = Getdate()

SET @Anniversary = Dateadd(yy,Datediff(yy,@BirthDate,@EndDate),@BirthDate)

INSERT @Age

SELECT Datediff(yy,@BirthDate,@EndDate) - (CASE

WHEN @Anniversary > @EndDate THEN 1

ELSE 0

END), 0, 0

UPDATE @Age SET Months = Month(@EndDate - @Anniversary) - 1

UPDATE @Age SET Days = Day(@EndDate - @Anniversary) - 1

RETURN

END

GO

-- Test table-valued UDF

SELECT * FROM fnAge('1956-10-23')

SELECT * FROM dbo.fnAge('1956-10-23')

/* Results

Years Months Days

52 4 1

*/

----------

-- SQL date range between

----------

-- SQL between dates

USE AdventureWorks;

-- SQL between

SELECT POs=COUNT(*) FROM Purchasing.PurchaseOrderHeader

WHERE OrderDate BETWEEN '20040301' AND '20040315'

-- Result: 108

-- BETWEEN operator is equivalent to >=...AND....<=

SELECT POs=COUNT(*) FROM Purchasing.PurchaseOrderHeader

WHERE OrderDate

BETWEEN '2004-03-01 00:00:00.000' AND '2004-03-15 00:00:00.000'

/*

Orders with OrderDates

'2004-03-15 00:00:01.000' - 1 second after midnight (12:00AM)

'2004-03-15 00:01:00.000' - 1 minute after midnight

'2004-03-15 01:00:00.000' - 1 hour after midnight

are not included in the two queries above.

*/

-- To include the entire day of 2004-03-15 use the following two solutions

SELECT POs=COUNT(*) FROM Purchasing.PurchaseOrderHeader

WHERE OrderDate >= '20040301' AND OrderDate < '20040316'

-- SQL between with DATE type (SQL Server 2008)

SELECT POs=COUNT(*) FROM Purchasing.PurchaseOrderHeader

WHERE CONVERT(DATE, OrderDate) BETWEEN '20040301' AND '20040315'

----------

-- Non-standard format conversion: 2011 December 14

-- SQL datetime to string

SELECT [YYYY Month DD] =

CAST(YEAR(GETDATE()) AS VARCHAR(4))+ ' '+

DATENAME(MM, GETDATE()) + ' ' +

CAST(DAY(GETDATE()) AS VARCHAR(2))

-- Converting datetime to YYYYMMDDHHMMSS format: 20121214172638

SELECT replace(convert(varchar, getdate(),111),'/','') +

replace(convert(varchar, getdate(),108),':','')

-- Datetime custom format conversion to YYYY_MM_DD

select CurrentDate=rtrim(year(getdate())) + '_' +

right('0' + rtrim(month(getdate())),2) + '_' +

right('0' + rtrim(day(getdate())),2)

-- Converting seconds to HH:MM:SS format

declare @Seconds int

set @Seconds = 10000

select TimeSpan=right('0' +rtrim(@Seconds / 3600),2) + ':' +

right('0' + rtrim((@Seconds % 3600) / 60),2) + ':' +

right('0' + rtrim(@Seconds % 60),2)

-- Result: 02:46:40

-- Test result

select 2*3600 + 46*60 + 40

-- Result: 10000

-- Set the time portion of a datetime value to 00:00:00.000

-- SQL strip time from date

-- SQL strip time from datetime

SELECT CURRENT_TIMESTAMP ,DATEADD(dd, DATEDIFF(dd, 0, CURRENT_TIMESTAMP), 0)

-- Results: 2014-01-23 05:35:52.793 2014-01-23 00:00:00.000

/* VALID DATE RANGES FOR DATE/DATETIME DATA TYPES

SMALLDATETIME (4 bytes) date range:

January 1, 1900 through June 6, 2079

DATETIME (8 bytes) date range:

January 1, 1753 through December 31, 9999

DATETIME2 (8 bytes) date range (SQL Server 2008):

January 1,1 AD through December 31, 9999 AD

DATE (3 bytes) date range (SQL Server 2008):

January 1, 1 AD through December 31, 9999 AD

*******/

-- Selecting with CONVERT into different styles

-- Note: Only Japan & ISO styles can be used in ORDER BY

SELECT TOP(1)

Italy = CONVERT(varchar, OrderDate, 105)

, USA = CONVERT(varchar, OrderDate, 110)

, Japan = CONVERT(varchar, OrderDate, 111)

, ISO = CONVERT(varchar, OrderDate, 112)

FROM AdventureWorks.Purchasing.PurchaseOrderHeader

ORDER BY PurchaseOrderID DESC

/* Results

Italy USA Japan ISO

25-07-2004 07-25-2004 2004/07/25 20040725

*/

-- SQL Server convert date to integer

DECLARE @Datetime datetime

SET @Datetime = '2012-10-23 10:21:05.345'

SELECT DateAsInteger = CAST (CONVERT(varchar,@Datetime,112) as INT)

-- Result: 20121023

-- SQL Server convert integer to datetime

DECLARE @intDate int

SET @intDate = 20120315

SELECT IntegerToDatetime = CAST(CAST(@intDate as varchar) as datetime)

-- Result: 2012-03-15 00:00:00.000

-------------

-- Julian date (YYYYDDD) to date / datetime converter

------------

CREATE FUNCTION dbo.fnJulianToDate (@JulianDt char(7))

RETURNS date AS

BEGIN

RETURN (SELECT DATEADD(day, CAST(RIGHT(@JulianDt,3) AS int) - 1,

CONVERT(datetime, LEFT(@JulianDt,4) + '0101', 112)))

END

GO

SELECT dbo.fnJulianToDate ('2016040')

-- 2016-02-09

------------

-----------

-- SQL Server CONVERT script applying table INSERT/UPDATE

------------

-- SQL Server convert date

-- Datetime column is converted into date only string column

USE tempdb;

GO

CREATE TABLE sqlConvertDateTime (

DatetimeCol datetime,

DateCol char(8));

INSERT sqlConvertDateTime (DatetimeCol) SELECT GETDATE()

UPDATE sqlConvertDateTime

SET DateCol = CONVERT(char(10), DatetimeCol, 112)

SELECT * FROM sqlConvertDateTime

-- SQL Server convert datetime

-- The string date column is converted into datetime column

UPDATE sqlConvertDateTime

SET DatetimeCol = CONVERT(Datetime, DateCol, 112)

SELECT * FROM sqlConvertDateTime

-- Adding a day to the converted datetime column with DATEADD

UPDATE sqlConvertDateTime

SET DatetimeCol = DATEADD(day, 1, CONVERT(Datetime, DateCol, 112))

SELECT * FROM sqlConvertDateTime

-- Equivalent formulation - SQL Server CAST datetime

UPDATE sqlConvertDateTime

SET DatetimeCol = DATEADD(dd, 1, CAST(DateCol AS datetime))

SELECT * FROM sqlConvertDateTime

GO

DROP TABLE sqlConvertDateTime

GO

/* First results

DatetimeCol DateCol

2014-12-25 16:04:15.373 20141225 */

/* Second results:

DatetimeCol DateCol

2014-12-25 00:00:00.000 20141225 */

/* Third results:

DatetimeCol DateCol

2014-12-26 00:00:00.000 20141225 */

------------

-- SQL month sequence - SQL date sequence generation with table variable

-- SQL Server cast string to datetime - SQL Server cast datetime to string

-- SQL Server insert default values method

DECLARE @Sequence table (Sequence int identity(1,1))

DECLARE @i int; SET @i = 0

DECLARE @StartDate datetime;

SET @StartDate = CAST(CONVERT(varchar, year(getdate()))+

RIGHT('0'+convert(varchar,month(getdate())),2) + '01' AS DATETIME)

WHILE ( @i < 120)

BEGIN

INSERT @Sequence DEFAULT VALUES

SET @i = @i + 1

END

SELECT MonthSequence = CAST(DATEADD(month, Sequence,@StartDate) AS varchar)

FROM @Sequence

GO

/* Partial results:

MonthSequence

Jan 1 2012 12:00AM

Feb 1 2012 12:00AM

Mar 1 2012 12:00AM

Apr 1 2012 12:00AM

*/

------------

------------

-- SQL Server Server datetime internal storage - SQL Server datetime formats

------------

-- SQL Server datetime to hex

SELECT Now=CURRENT_TIMESTAMP, HexNow=CAST(CURRENT_TIMESTAMP AS BINARY(8))

/* Results

Now HexNow

2009-01-02 17:35:59.297 0x00009B850122092D

*/

-- SQL Server date part - left 4 bytes - Days since 1900-01-01

SELECT Now=DATEADD(DAY, CONVERT(INT, 0x00009B85), '19000101')

GO

-- Result: 2009-01-02 00:00:00.000

-- SQL time part - right 4 bytes - milliseconds since midnight

-- 1000/300 is an adjustment factor

-- SQL dateadd to Midnight

SELECT Now=DATEADD(MS, (1000.0/300)* CONVERT(BIGINT, 0x0122092D), '2009-01-02')

GO

-- Result: 2009-01-02 17:35:59.290

------------

------------

-- String date and datetime date&time columns usage
-- SQL Server datetime formats in tables

------------

USE tempdb;

SET NOCOUNT ON;

-- SQL Server select into table create

SELECT TOP (5)

FullName=convert(nvarchar(50),FirstName+' '+LastName),

BirthDate = CONVERT(char(8), BirthDate,112),

ModifiedDate = getdate()

INTO Employee

FROM AdventureWorks.HumanResources.Employee e

INNER JOIN AdventureWorks.Person.Contact c

ON c.ContactID = e.ContactID

ORDER BY EmployeeID

GO

-- SQL Server alter table

ALTER TABLE Employee ALTER COLUMN FullName nvarchar(50) NOT NULL

GO

ALTER TABLE Employee

ADD CONSTRAINT [PK_Employee] PRIMARY KEY (FullName )

GO

/* Results

Table definition for the Employee table

Note: BirthDate is string date (only)

CREATE TABLE dbo.Employee(

FullName nvarchar(50) NOT NULL PRIMARY KEY,

BirthDate char(8) NULL,

ModifiedDate datetime NOT NULL

)

*/

SELECT * FROM Employee ORDER BY FullName

GO

/* Results

FullName BirthDate ModifiedDate

Guy Gilbert 19720515 2009-01-03 10:10:19.217

Kevin Brown 19770603 2009-01-03 10:10:19.217

Rob Walters 19650123 2009-01-03 10:10:19.217

Roberto Tamburello 19641213 2009-01-03 10:10:19.217

Thierry D'Hers 19490829 2009-01-03 10:10:19.217

*/

-- SQL Server age

SELECT FullName, Age = DATEDIFF(YEAR, BirthDate, GETDATE()),

RowMaintenanceDate = CAST (ModifiedDate AS varchar)

FROM Employee ORDER BY FullName

GO

/* Results

FullName Age RowMaintenanceDate

Guy Gilbert 37 Jan 3 2009 10:10AM

Kevin Brown 32 Jan 3 2009 10:10AM

Rob Walters 44 Jan 3 2009 10:10AM

Roberto Tamburello 45 Jan 3 2009 10:10AM

Thierry D'Hers 60 Jan 3 2009 10:10AM

*/

-- SQL Server age of Rob Walters on specific dates

-- SQL Server string to datetime implicit conversion with DATEADD

SELECT AGE50DATE = DATEADD(YY, 50, '19650123')

GO

-- Result: 2015-01-23 00:00:00.000

-- SQL Server datetime to string, Italian format for ModifiedDate

-- SQL Server string to datetime implicit conversion with DATEDIFF

SELECT FullName,

AgeDEC31 = DATEDIFF(YEAR, BirthDate, '20141231'),

AgeJAN01 = DATEDIFF(YEAR, BirthDate, '20150101'),

AgeJAN23 = DATEDIFF(YEAR, BirthDate, '20150123'),

AgeJAN24 = DATEDIFF(YEAR, BirthDate, '20150124'),

ModDate = CONVERT(varchar, ModifiedDate, 105)

FROM Employee

WHERE FullName = 'Rob Walters'

ORDER BY FullName

GO

/* Results

Important Note: age increments on Jan 1 (not as commonly calculated)

FullName AgeDEC31 AgeJAN01 AgeJAN23 AgeJAN24 ModDate

Rob Walters 49 50 50 50 03-01-2009 */

------------

-- SQL combine integer date & time into datetime

------------

-- Datetime format sql

-- SQL stuff

DECLARE @DateTimeAsINT TABLE ( ID int identity(1,1) primary key,

DateAsINT int,

TimeAsINT int

)

-- NOTE: leading zeroes in time is for readability only!

INSERT @DateTimeAsINT (DateAsINT, TimeAsINT) VALUES (20121023, 235959)

INSERT @DateTimeAsINT (DateAsINT, TimeAsINT) VALUES (20121023, 010204)

INSERT @DateTimeAsINT (DateAsINT, TimeAsINT) VALUES (20121023, 002350)

INSERT @DateTimeAsINT (DateAsINT, TimeAsINT) VALUES (20121023, 000244)

INSERT @DateTimeAsINT (DateAsINT, TimeAsINT) VALUES (20121023, 000050)

INSERT @DateTimeAsINT (DateAsINT, TimeAsINT) VALUES (20121023, 000006)

SELECT DateAsINT, TimeAsINT,

CONVERT(datetime, CONVERT(varchar(8), DateAsINT) + ' '+

STUFF(STUFF ( RIGHT(REPLICATE('0', 6) + CONVERT(varchar(6), TimeAsINT), 6),

3, 0, ':'), 6, 0, ':')) AS DateTimeValue

FROM @DateTimeAsINT

ORDER BY ID

GO

/* Results

DateAsINT TimeAsINT DateTimeValue

20121023 235959 2012-10-23 23:59:59.000

20121023 10204 2012-10-23 01:02:04.000

20121023 2350 2012-10-23 00:23:50.000

20121023 244 2012-10-23 00:02:44.000

20121023 50 2012-10-23 00:00:50.000

20121023 6 2012-10-23 00:00:06.000

*/

------------

-- SQL Server string to datetime, implicit conversion with assignment

UPDATE Employee SET ModifiedDate = '20150123'

WHERE FullName = 'Rob Walters'

GO

SELECT ModifiedDate FROM Employee WHERE FullName = 'Rob Walters'

GO

-- Result: 2015-01-23 00:00:00.000

/* SQL string date, assemble string date from datetime parts */

-- SQL Server cast string to datetime - sql convert string date

-- SQL Server number to varchar conversion

-- SQL Server leading zeroes for month and day

-- SQL Server right string function

UPDATE Employee SET BirthDate =

CONVERT(char(4),YEAR(CAST('1965-01-23' as DATETIME)))+

RIGHT('0'+CONVERT(varchar,MONTH(CAST('1965-01-23' as DATETIME))),2)+

RIGHT('0'+CONVERT(varchar,DAY(CAST('1965-01-23' as DATETIME))),2)

WHERE FullName = 'Rob Walters'

GO

SELECT BirthDate FROM Employee WHERE FullName = 'Rob Walters'

GO

-- Result: 19650123

-- Perform cleanup action

DROP TABLE Employee

-- SQL nocount

SET NOCOUNT OFF;

GO

------------

------------

-- sql isdate function

------------

USE tempdb;

-- sql newid - random sort

SELECT top(3) SalesOrderID,

stringOrderDate = CAST (OrderDate AS varchar)

INTO DateValidation

FROM AdventureWorks.Sales.SalesOrderHeader

ORDER BY NEWID()

GO

SELECT * FROM DateValidation

/* Results

SalesOrderID stringOrderDate

56720 Oct 26 2003 12:00AM

73737 Jun 25 2004 12:00AM

70573 May 14 2004 12:00AM

*/

-- SQL update with top

UPDATE TOP(1) DateValidation

SET stringOrderDate = 'Apb 29 2004 12:00AM'

GO

-- SQL string to datetime fails without validation

SELECT SalesOrderID, OrderDate = CAST (stringOrderDate as datetime)

FROM DateValidation

GO

/* Msg 242, Level 16, State 3, Line 1

The conversion of a varchar data type to a datetime data type resulted in an

out-of-range value.

*/

-- sql isdate - filter for valid dates

SELECT SalesOrderID, OrderDate = CAST (stringOrderDate as datetime)

FROM DateValidation

WHERE ISDATE(stringOrderDate) = 1

GO

/* Results

SalesOrderID OrderDate

73737 2004-06-25 00:00:00.000

70573 2004-05-14 00:00:00.000

*/

-- SQL drop table

DROP TABLE DateValidation

Go

------------

-- SELECT between two specified dates - assumption TIME part is 00:00:00.000

------------

-- SQL datetime between

-- SQL select between two dates

SELECT EmployeeID, RateChangeDate

FROM AdventureWorks.HumanResources.EmployeePayHistory

WHERE RateChangeDate >= '1997-11-01' AND

RateChangeDate < DATEADD(dd,1,'1998-01-05')

GO

/* Results

EmployeeID RateChangeDate

3 1997-12-12 00:00:00.000

4 1998-01-05 00:00:00.000

*/

/* Equivalent to

-- SQL datetime range

SELECT EmployeeID, RateChangeDate

FROM AdventureWorks.HumanResources.EmployeePayHistory

WHERE RateChangeDate >= '1997-11-01 00:00:00' AND

RateChangeDate < '1998-01-06 00:00:00'

GO

*/

------------

-- SQL datetime language setting

-- SQL Nondeterministic function usage - result varies with language settings

SET LANGUAGE 'us_english'; –– Jan 12 2015 12:00AM

SELECT US = convert(VARCHAR,convert(DATETIME,'01/12/2015'));

SET LANGUAGE 'British'; –– Dec 1 2015 12:00AM

SELECT UK = convert(VARCHAR,convert(DATETIME,'01/12/2015'));

SET LANGUAGE 'German'; –– Dez 1 2015 12:00AM

SET LANGUAGE 'Deutsch'; –– Dez 1 2015 12:00AM

SELECT Germany = convert(VARCHAR,convert(DATETIME,'01/12/2015'));

SET LANGUAGE 'French'; –– déc 1 2015 12:00AM

SELECT France = convert(VARCHAR,convert(DATETIME,'01/12/2015'));

SET LANGUAGE 'Spanish'; –– Dic 1 2015 12:00AM

SELECT Spain = convert(VARCHAR,convert(DATETIME,'01/12/2015'));

SET LANGUAGE 'Hungarian'; –– jan 12 2015 12:00AM

SELECT Hungary = convert(VARCHAR,convert(DATETIME,'01/12/2015'));

SET LANGUAGE 'us_english';

GO
------------

-- SQL Server 2008 T-SQL find next Monday for a given date

DECLARE @DateTime DATETIME = '2012-12-31'

SELECT NextMondaysDate=DATEADD(dd,(DATEDIFF(dd, 0, @DateTime) / 7 * 7) + 7, 0),

WeekDayName=DATENAME(dw,DATEADD(dd,(DATEDIFF(dd, 0, @DateTime) / 7 * 7) + 7, 0));

/*

NextMondaysDate WeekDayName

2013-01-07 00:00:00.000 Monday

*/

------------

------------

-- Function for Monday dates calculation

------------

USE AdventureWorks2008;

GO

-- SQL user-defined function

-- SQL scalar function - UDF

CREATE FUNCTION fnMondayDate

(@Year INT,

@Month INT,

@MondayOrdinal INT)

RETURNS DATETIME

AS

BEGIN

DECLARE @FirstDayOfMonth CHAR(10),

@SeedDate CHAR(10)

SET @FirstDayOfMonth = convert(VARCHAR,@Year) + '-' + convert(VARCHAR,@Month) + '-01'

SET @SeedDate = '1900-01-01'

RETURN DATEADD(DD,DATEDIFF(DD,@SeedDate,DATEADD(DD,(@MondayOrdinal * 7) - 1,

@FirstDayOfMonth)) / 7 * 7, @SeedDate)

END

GO

-- Test Datetime UDF - Third Monday in Feb, 2015

SELECT dbo.fnMondayDate(2016,2,3)

-- 2015-02-16 00:00:00.000

-- First Monday of current month

SELECT dbo.fnMondayDate(Year(getdate()),Month(getdate()),1)

-- 2009-02-02 00:00:00.000

------------

Related link: http://www.sqlusa.com/bestpractices/datetimeconversion/