Thursday, April 30, 2015

Identity colunm things in sql server

1) How to update values in identity column in sql server..?
sol:  You cannot update an IDENTITY column. You need to move the data into another table make the changes over there and insert the back the data into original table.

2) How to see next identity value in sql server through query..?
sol: DBCC Checkident ('TableName')
ex: DBCC Checkident ('EMP')

3) How to reset identity seed value in sql server.?
Sol: DBCC CHECKIDENT ('TableName', RESEED, number)
ex: DBCC Checkident ('EMP',RESEED,11)

Tuesday, April 21, 2015

Flat file of types fixed width and Ragged right problem, while exporting..?

I’m using the Import\Export wizard to export the top 5 lines from a MS Sql table into a fixed format (“ragged”) file. But I want the first record to contain the column names of the exported fields so I selected the “Column names in the first data row” option of the “Choose a Destination” box. When I run the Package I get:
>>>
· Information 0x402090dc: Data Flow Task: The processing of file "C:\barkingdog\ExportWithheader.txt" has started (SQL Server Import and Export Wizard)
· Error 0xc0202095: Data Flow Task: Failed to write out column name for column "CustomerID".
(SQL Server Import and Export Wizard)
Error 0xc004701a: Data Flow Task: component "Destination - ExportWithheader_txt" (49) failed the pre-execute phase and returned error code 0xC0202095.
(SQL Server Import and Export Wizard)
>>>
When I de-select the “Column names” option, the package works fine. Other than manually, how can I et the column names in output file?
 
 
 
 
Answer:
 
 
The problem here is that when you include column names in the first data row, then you might need to modify the column width (for a ragged right file). For example, if you have a column CustomerID which is of type DT_STR(5), it will fail trying to write "CustomerID" in that space, which takes 10 characters. Use the Edit Transform button on configure Flat File Destination page of the Import Export Wizard to adjust the length specified for each fixed width column.


hope that helps.

What are the Data types used in excel EXCEL..?

Yes, string fields in Excel are treated as Unicode string fields by the driver. Here is some content written about moving data in the other direction that applies here too:

Data types. The Excel driver uses only six data types, which Integration Services maps as follows:

  • Numeric – double-precision float (DT_R8)
  • Currency – currency (DT_CY)
  • Boolean – Boolean (DT_BOOL)
  • Date/time – date (DT_DATE)
  • String – Unicode string, length 255 (DT_WSTR)
  • Memo – Unicode text stream (DT_NTEXT)

Sunday, April 12, 2015

What is line feed and Carriage return in Flat file in SSIS

A line feed means moving one line forward. The code is \n. A carriage return means moving the cursor to the beginning of the line. The code is \r.

The separation comes from typewriter times, when you turned the wheel to move the paper to change the line and moved the carriage to restart typing on the beginning of a line. This was two steps.
Windows editors often still use the combination of both in text files. Unix uses mostly only the \n.

Saturday, April 11, 2015

Data types in SQL Server


There is no difference between NUMERIC and DECIMAL data types. They are synonymous to each other and either one can be used. DECIMAL/NUMERIC data types are numeric data types with fixed precision and scale.
DECIMAL (p [, s ])
NUMERIC (p [, s ])
In declaring a DECIMAL or NUMERIC data type, p, which is the precision, specifies 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 s is the scale and it specifies the maximum number of decimal digits that can be stored to the right of the decimal point. Scale, which defaults to 0 if not specified, must be a value from 0 to the precision value.
The following table specifies the storage size required based on the precision specified for the NUMERIC or DECIMAL data type:
Precision Storage Size
1 - 9 5 bytes
10- 19 9 bytes
20-28 13 bytes
29-38 17 bytes

FLOAT and REAL data types are both approximate number data types for use with floating point numeric data. Floating point data is approximate; not all values in the data type range can be precisely represented. The differences between these 2 data types are in the minimum and maximum values each can hold as well as the storage size required, as specified in the following table:
Data Type n Minimum Value Maximum Value Precision Storage Size
float [(n)] 1-24 -1.79E + 308 1.79E + 308 7 digits 4 bytes
25-53 -1.79E + 308 1.79E + 308 15 digits 8 bytes
real -3.40E + 38 3.40E + 38 7 digits 4 bytes
For FLOAT data type, the n is the number of bits used to store the mantissa in scientific notation and thus dictates the precision and storage size and it must be a value from 1 through 53. If not specified, this defaults to 53. In SQL Server, the synonym for REAL data type is FLOAT(24). If your data requires only a maximum of 7 digits precision, you can either use the REAL data type or FLOAT data type with 24 as the parameter (FLOAT(24)).


SQL SERVER – 2005 Replace TEXT with VARCHAR(MAX) – Stop using TEXT, NTEXT, IMAGE Data Types

TEXT, NTEXT and IMAGE data types of SQL Server 2000 will be deprecated in future version of SQL Server, SQL Server 2005 provides backward compatibility to data types but it is recommanded to use new data types which are VARHCAR(MAX), NVARCHAR(MAX) and VARBINARY(MAX).
Maximum size supported by TEXT and Varchar(max) are same.
Maximum size supported by NTEXT and NVarchar(max) are same.
Maximum size supported by Image and Varbinary(max) are same.

 

Thursday, April 9, 2015

How to Use the Microsoft Batch File Language

 

Batch files are DOS command line commands batched together. In Linux they are known as shell scripts, and follow a completely different syntax.

I am aware of these batch files....

Saturday, March 21, 2015

What is Index Position in Cache Transformation in SSIS

 
The Cache connection manager reads a reference dataset from the Cache transform or from a cache file (.caw), and can save the data to a cache file. The data is always stored in memory.

- The Cache connection manager does not support the Binary Large Object (BLOB) data types DT_TEXT, DT_NTEXT, and DT_IMAGE




Specify which columns are index columns by specifying the index position of each column. The index is a collection of one or more columns.

For non-index columns, the index position is 0.

For index columns, the index position is a sequential, positive number. This number indicates the order in which the Lookup transformation compares rows in the reference dataset to rows in the input data source. The column with the most unique values should have the lowest index position.


The column which we specified as index Position, those all should be used as lookup search.


If you configure the cache connection manager to use a cache file, the connection manager will do one of the following actions:

- Save data to the file when a Cache Transform transformation is configured to write data from a data source in the data flow to the Cache connection manager. For more information, see Cache Transform.
- Read data from the cache file.

Saturday, March 14, 2015

What's the difference between installing a "Default Instance" vs a "Named Instance"?


You can install only one default instance but can install multiple named instances.

The underlying difference between a default and named instance is mostly a matter of network connectivity. Clients can connect to the default instance using only the host name over the well-known 1433 port. To connect to a named instance, clients specify the host and instance name (e.g. "MyHost\My_Instance").



If you're only going to install one version of SQL Server on this machine, go with a default. If you're planning on multiple instances on this machine, it's up to you whether you want one named and one default, or both named.

Thursday, February 26, 2015

What is ip address to a computer..?

"IP" stands for Internet Protocol, so an IP address is an Internet Protocol address. What does that mean? An Internet Protocol is a set of rules that govern Internet activity and facilitate completion of a variety of actions on the World Wide Web. Therefore an Internet Protocol address is part of the systematically laid out interconnected grid that governs online communication by identifying both initiating devices and various Internet destinations, thereby making two-way communication possible.
An IP address consists of four numbers, each of which contains one to three digits, with a single dot (.) separating each number or set of digits. Each of the four numbers can range from 0 to 255. Here's an example of what an IP address might look like: 78.125.0.209. This innocuous-looking group of four numbers is the key that empowers you and me to send and retrieve data over our Internet connections, ensuring that our messages, as well as our requests for data and the data we've requested, will reach their correct Internet destinations. Without this numeric protocol, sending and receiving data over the World Wide Web would be impossible.
IP addresses can be either static or dynamic. Static IP addresses never change. They serve as a permanent Internet address and provide a simple and reliable way for remote computers to contact you. Static IP addresses reveal such information as the continent, country, region, and city in which a computer is located; the ISP (Internet Service Provider) that services that particular computer; and such technical information as the precise latitude and longitude of the country, as well as the locale, of the computer. Many websites provide IP address look-up services to their visitors, free of charge. If you're curious about your own IP address, you can locate these websites by performing a Google search.
Dynamic IP addresses are temporary and are assigned each time a computer accesses the Internet. They are, in effect, borrowed from a pool of IP addresses that are shared among various computers. Since a limited number of static IP addresses are available, many ISPs reserve a portion of their assigned addresses for sharing among their subscribers in this way. This lowers costs and allows them to service far more subscribers than they otherwise could.

Determining if your IP is Static or Dynamic

The process for determining what type of IP address you have is relatively simple, but it varies amongst operating systems.

Windows

Execute the following command from a command prompt:
ipconfig /all
Find the line containing DHCP Enabled which is found in the below block
Physical Address. . . . . . . . . : 00-00-00-00-00-00-00-E0
DHCP Enabled. . . . . . . . . . . : No
Autoconfiguration Enabled . . . . : Yes
If that value is set to Yes then you have a static IP address and if it is No your IP address is dynamic.