How to debug T-SQL statement in SQL Server Management Studio


Debugging is an important feature for every programming language with no exception SQL Server has this to help developer trace the their code and remove potential logical issue in the code before moving to production environment or simply to find the bug in the code.

SQL Server management Studio (SSMS) provide easy way to debug T-SQL statements.

Expectation: This blog post is to show how to use debug feature in SSMS with simple T-SQL statement.

T-SQL

declare @i as int, @n as int;
set @i = 0;
set @n = 5;

while @i < @n
begin
set @i = @i + 1;
print @i;
end

Step 1: Open new query window and paste the above code

Step 2: Click Debug button on the toolbar

debug_button

Step 3: Once debug starts, another debug related toolbar and windows (local variables, call stack) will show up. We can view and modify local variables and parameters, view global variables, as well as control and manage breakpoints while debugging.

debug_window

Step 3: Click Step into (F11 – function key) to execute step by step.

This image is captured after 3 iterations. so, we can see the value of the variable @i = 3 and @n =5.

iteration

Try other debugging features in SSMS and keep  your code robust. Thanks.

Reference

Categories: SQL Server Tags:

Synchronize Table – SQL Server

September 1, 2015 2 comments

We have been doing table synchronize for many years using various techniques. Merge statement in SQL Server is not new for us. But, I liked this statement. So, I decided to write a simple note about it.

Expectation: This blog post is for beginners those who want to learn about this Merge statement using simple examples.

We can perform insert, update, or delete operations on a target table based using single statement based on the results of joining source and target table. For example, you can synchronize two tables by inserting, updating, or deleting rows in one table based on differences found in the other table. – MSDN reference

Creating working environment:

This is the main (target) table that we are going to use for synchronization.

declare @emp as table
(
EmployeeId int not null primary key,
DepartmentId int not null,
EmployeeName varchar(50) not null
)

This is the stage table to hold the data for sync.

declare @emp_stg as table
(
EmployeeId int not null,
DepartmentId int not null,
EmployeeName varchar(50) not null
)

Loading few rows to the stage table.

Insert into @emp_stg (EmployeeId, DepartmentId, EmployeeName) values (1,1, ‘Robert’);
Insert into @emp_stg (EmployeeId, DepartmentId, EmployeeName) values (2,2, ‘Bobby’);
Insert into @emp_stg (EmployeeId, DepartmentId, EmployeeName) values (3,2, ‘Dan’);
Insert into @emp_stg (EmployeeId, DepartmentId, EmployeeName) values (4,3, ‘Johnson’);
Insert into @emp_stg (EmployeeId, DepartmentId, EmployeeName) values (5,4, ‘Monti’);

Now, using merge statement we are going to insert new rows to the main table @emp.

MERGE @emp as tgt
USING @emp_stg as src
ON src.employeeid = tgt.employeeid
WHEN NOT MATCHED BY TARGET THEN
INSERT  (employeeid, departmentid, employeename)
VALUES (src.employeeid, src.departmentid, src.employeename)
OUTPUT $Action, inserted.*
;

$Action column will have the DML operation string value such as ‘INSERT’ or ‘UPDATE’ or ‘DELETE’. inserted.* will give us the news inserted row(s).

Now, We are now going to update the rows if there is a change in the incoming data.

This is a simple DML update statement for this experiment.

UPDATE @emp_stg set EmployeeName = ‘robert k’ where EmployeeId=1;

MERGE @emp as tgt
USING @emp_stg as src
ON src.employeeid = tgt.employeeid
WHEN MATCHED AND
(src.departmentid <> tgt.departmentid or
src.employeename <> tgt.employeename)
THEN
UPDATE SET tgt.departmentid = src.departmentid,
tgt.employeename = src.employeename
OUTPUT $Action, inserted.*
;

Following merge statement is to perform table sync with delete operation for the unavailable data.

DELETE from  @emp_stg where EmployeeId=3;

MERGE @emp as tgt
USING @emp_stg as src
ON src.employeeid = tgt.employeeid
WHEN NOT MATCHED BY SOURCE THEN
DELETE
OUTPUT $Action, deleted.*
;

I have separated Insert, Update and Delete operation for this example to show the flexibility of the Merge statement. But, These statements can be used together to perform all in one operation.

Categories: SQL Server Tags: ,

Power BI Desktop


Power BI is the latest hot top in the BI community in recent days. I download and install the Power BI Desktop tool in my machine and exploring now. I am amazed with the performance of this tool. As always Microsoft has done a wonder job. It is lighter and faster. Having ability to connect with different data source, transformation feature and report. I would say, it is all in one tool.

pic1

This is the final dialog box before entering into a new world.

Download a free copy of desktop powerbi

I have created a quick map report using Power BI desktop

map

I am planning to write more about this tool in coming days.

Categories: PowerBI Tags:

Get the File Last Modified datetime from HTTP Header – SSIS


This VB.Net code can be used to get the Last modified date of a file from HTTP header. It can be used to check the file date before the actual file is downloaded to out computer. It save some time and network resources. You can pass different header key to get its value.

But, this example is to get the last modified date of a file from Houstontx.gov website.

Dim request As HttpWebRequest = HttpWebRequest.Create _
(“http://gisdata.houstontx.gov/cohgis/cohgis2011_2010census10.zip“)
Dim response As HttpWebResponse

response = request.GetResponse()

Dim HTTPHeader_LastModified_Datetime As String
HTTPHeader_LastModified_Datetime = response.GetResponseHeader(“Last-Modified”)

MsgBox(HTTPHeader_LastModified_Datetime)

Hope you will like it.

Categories: SQL Server

Get the File Last Modified datetime from FTP Server – SSIS


There are many ways to get the file modified date from the FTP server. But, I like to write a VB.net code to do that task simpler. Script Task is used in SSIS.

Code: To fetch the file last modified datetime

Imports System.Net

Dim reqFTP As FtpWebRequest = DirectCast(FtpWebRequest.Create(New Uri(“ftp://SERVERName/FileName”)),  FtpWebRequest)

reqFTP.Method = WebRequestMethods.Ftp.GetDateTimestamp

reqFTP.Credentials = New NetworkCredential(“USER NAME”, “PASSWORD”)

response = DirectCast(reqFTP.GetResponse(), FtpWebResponse)

MsgBox(response.LastModified.ToString)

reqFTP.Abort()

Using Credentials is based on the server requirement. In this script, file date time is just displayed using Message box. We can use package variable to store the value.

Categories: SQL Server

Read and Write to Text file – VB.Net


I created this snippet to save my search time in future. So, you can also make use of this if needed.

The main objective of this code is to read a text file line by line and write it into another file. I know, it looks silly. because, why do we need to read a file and write to others without doing anything. But, The actual purpose is to read a text file and do some operations like update or remove. Using this method I can keep my original file unchanged. does it make sense now?

Code snippet

Imports System.IO

Dim strLine As String
Dim objStreamReader As StreamReader
Dim objStreamWriter As StreamWriter

objStreamReader = New StreamReader(“C:\test\source.txt”)
objStreamWriter = New StreamWriter(“C:\test\destination.txt”)

strLine = objStreamReader.ReadLine

Do While Not strLine Is Nothing
objStreamWriter.WriteLine(strLine)
strLine = objStreamReader.ReadLine
Loop

‘Close the file.
objStreamWriter.Close()
objStreamReader.Close()

I know there are millions of ways to do something. But, I choose this method and if you have a new logic please share it in the comment section.

Reference

Categories: SQL Server

SQL SERVER – Hotfixes for SQL Server 2014


Microsoft released the hotfixes for the latest version of MS SQL Server – SQL Server 2014 CU 4. The new build number for this cumulative update 4 (CU 4)  is 12.0.2430.0

The full list of hotfixes provided in this release are compiled in the excel file. Download SQL Server 2014 CU 4 hot fixes excel file.

Hotfixes Statistics

Fix area No Of Fixes
SQL Service 13
Analysis Services 10
Reporting Services 8
Management Tools 7
SQL performance 5
DQS 3
Integration Services 3
Data Quality Services (DQS) 1
SQL connectivity 1
High Availability 1
BI Azure 1
In-Memory OLTP 1
Grand Total 54

Download Hotfix now

Source: http://support.microsoft.com/kb/2999197

Categories: SQL Server
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