SqlParameter in asp.net

I have a web service, so the handler is called multiple times concurrently all the time.

Inside I create SqlConnection and SqlCommand. I have to execute about 7 different commands. Different commands require various parameters, so I just add them once:

How to connect to an external SQL server database in ASP.NET / VB.NET / .NET

Connecting to databases in .NET is different if you are coming from other languages such as PHP. To connect to a database in ASP.NET / .NET in general, you use "Connection Strings" that essentially is the connection information to the database.

First and foremost, in your code behind file within an ASP.NET application (or simply the .vb or .cs file of your .NET desktop application), you will need to first import the namespace that has the relevant database-related classes and methods, etc.

Execute SP_UPDATESTATS

The query optimizer uses the statistics to create the query plan to improve the query performance. The query optimizer automatically generates the necessary statistics to build high quality query plan to improve the performance of the query.

What is a multicast delegate?

A MulticastDelegate has a linked list of delegates, called an invocation list, consisting of one or more elements. When a multicast delegate is invoked, the delegates in the invocation list are called synchronously in the order in which they appear. If an error occurs during execution of the list then an exception is thrown

decimal and numeric (Transact-SQL)

Decimal and numeric

Numeric data types that have fixed precision and scale.

decimal [ (p[ ,s] )] and numeric[ (p[ ,s] )]

• Fixed precision and scale numbers. When maximum precision is used, valid values are from - 10^38 +1 through 10^38 - 1. The ISO synonyms for decimal are dec and dec(p, s). numeric is functionally equivalent to decimal.

• p (precision)

• The maximum total number of decimal digits that can be stored, both to the left and to the right of the decimal point. The precision must be a value from 1 through the maximum precision of 38. The default precision is 18.

• s (scale)

• The maximum number of decimal digits that can be stored to the right of the decimal point. Scale must be a value from 0 through p. Scale can be specified only if precision is specified. The default scale is 0; therefore, 0 <= s <= p. Maximum storage sizes vary, based on the precision.

Precision Storage bytes

1 - 9       5

10-19     9

20-28    13

29-38    17
As per my understanding NUMERIC(18, 10) column would take 18 decimal digits to the left of the decimal point and 10 to the right.

Example:

SELECT CAST(1234567891234567.34 AS NUMERIC(18,2))  --Works
SELECT CAST(1234567891234567.34 AS NUMERIC(18,10)) --fails with Arithmetic overflow error

it is clear that, in the first case from the statement NUMERIC(18,2) the total digits are 18 and 16 digits are available to the left of decimal, whereas 1234567891234567 are 16 digits. Hence, there is no error.
In the second case, from the statement NUMERIC(18,10), 8 digits are available to the left of decimal, but 1234567891234567 are 16 digits which is more than 8 digits. Hence, Arithmetic overflow error occurs.

Basic differences between Oracle and SQL Server

most obvious differences are:

• The FIRST biggest difference: Transaction control. In Oracle EVERYTHING is a transaction and it is not permanent until you COMMIT. In SQL Server, there is (by default) no transaction control. An error half way through a stored procedure WILL NOT ROLLBACK the DDL in previous steps.

Obviously, if you wrap the TSQL DML in BEGIN TRANSACTION and COMMIT then it will roll back but this is rare in SQL Server code I've seen.

• The SECOND biggest difference: MVCC. In SQL Server and Oracle is different. SQL Server will allow dirty reads, and writes can block reads in MS SQL (Again, it's configurable but the default in SQL Server is for performance and not read consistency, unlike Oracle where read consistency is default and unbendable.

Also consider:

• When you setup an Oracle server, you tend to have one database with many "users/schemas", and tablespaces that are shared by all your users. SQL Server has separate databases that do not share disk files.
• SQL Server uses "logins" to give you access to the SQL Server instance and each database has "users" that map to a login to get individual access to the tables and views etc.
• Typically, all the objects in a database are owned by dbo.
• TSQL is similar to PL/SQL, but (in my opinion) less powerful. You may need to simplify your SQL to get it to work as well as you'd expect in Oracle.
• The SQL Server Management Studio (2008 SP1) is fantastic!
• If you like Oracle, all the "getting under the hood" and "explain plan optimisation" then this training and experience will work well for you against guy's who just code straight SQL Server TSQL and expect the server to perform fast by magic.
• SQL Server does not have packages. This might start off as a bonus (PL/SQL packages can be a PITA) but eventually you'll start to get a big nest of similarly named stored procedures in the database and you'll wish there was a way you could organise and group then them better.

PARSENAME in Sql

DECLARE @t TABLE (A varchar(25))

INSERT @t values ('77.88.99.100') 

SELECT
  PARSENAME(A,1) AS 'First selected'
, PARSENAME(A,2) AS '2nd selected'
, PARSENAME(A,3) AS '3rd selected'
, PARSENAME(A,4) AS '4th selected'
 from @t

The question is: (select 1)

a. Are the values returned  First selected 77,  2nd selected 88,3rd selected 99,4th selected 100'

b. Are the values returned first selected 100,  2nd selected 99,3rd selected 88, 4th selected 77

c. No values are returned.