Sample Codes
Commonly used code snippets at one place
Read and Write Binary file: int, string
Read and Write Binary file: int, string
| Imports System.IO Module Module1 Sub Main() Dim Stream As FileStream 'Writing Try Stream = New FileStream("test.dat", FileMode.Create) Catch E As Exception Console.WriteLine("Error creating test.Dat") Console.WriteLine("Error {0}", E.Message) End Try Dim BinaryStream As New BinaryWriter(Stream) Dim Age As Integer = 21 Dim Salary As Double = 100000.0 Dim Name As String = "Joe" Try BinaryStream.Write(Age) BinaryStream.Write(Salary) BinaryStream.Write(Name) BinaryStream.Close() Console.WriteLine("Data written to test.Dat") Catch E As Exception Console.WriteLine("Error writing to test.Dat") Console.WriteLine("Error {0}", E.Message) End Try 'Reading Try Stream = New FileStream("test.dat", FileMode.Open) Catch E As Exception Console.WriteLine("Error opening test.Dat") Console.WriteLine("Error {0}", E.Message) End Try Dim BinaryStreamReader As New BinaryReader(Stream) Try Age = BinaryStreamReader.ReadInt32() Salary = BinaryStreamReader.ReadDouble() Name = BinaryStreamReader.ReadString() BinaryStreamReader.Close() Console.WriteLine("Age: {0}", Age) Console.WriteLine("Salary: {0}", Salary) Console.WriteLine("Name: {0}", Name) Catch E As Exception Console.WriteLine("Error reading to test.Dat") Console.WriteLine("Error {0}", E.Message) End Try End Sub End Module |
EXISTS operator returns TRUE if a subquery contains any rows
EXISTS operator returns TRUE if a subquery contains any rows. In the follwing example we want to retrive list of employees from department number 4, only if people from this department produced sales in 1999 :
| SELECT a.EmpNo, RTrim(a.FirstName) + ' ' + RTrim(a.LastName) AS EmpName, SUM(b.DocTotal) AS STotal FROM Employees AS a LEFT JOIN Invoice AS b ON a.EmpNo = b.SlpCode WHERE a.DeptNo = 4 AND EXISTS (SELECT * FROM Invoice AS t1 INNER JOIN Employees AS t2 ON t1.SlpCode = t2.EmpNo WHERE t2.DeptNo = 4 AND YEAR(t1.docdate)=1999) GROUP BY a.EmpNo, RTrim(a.FirstName) + ' ' + RTrim(a.LastName); |
Update Join syntax in TSQL
For some reason we need to put CustomerName in "Invoices" table. This table allready have CustomerID indicator:
| UPDATE a SET a.CustomerName = b.CustomerName FROM Invoice AS a INNER JOIN Customers AS b ON a.CustomerID = b.CustomerID |
Removing an Excel Workbook VBA Password
A VBA project password can be removed with a hex editor.
- Close the workbook and open the workbook file in the hex editor.
- Find the string "DPB" and change it to "DPx".
- Save the file.
- Open the workbook and click OK until the workbook is open (one or more dialogs are displayed describing various problems with the VBA project).
- Press ALT+F11, choose the menu command Tools->VBAProject Properties, navigate to the Protection tab, and change the password but do not remove it (note the new password).
- Save, close, and re-open the workbook.
- Press ALT+F11 and enter the new password.
- Choose Tools->VBAProject Properties, navigate to the Protection tab
- and remove the password.
- Save the workbook.
T-SQL code to find out the nth highest number in a column
CREATE PROC nthHighestNo
(
@table_name sysname,
@column_name sysname,
@nth int
)
AS
BEGIN
Regular Expressions in .NET
In this article, Darren explains a nice and simple way of how to use regular expression in .Net. For those who are confused about how regular expressions work, this article is for you.
Subscribe to:
Posts (Atom)