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Posts Tagged ‘raresql’

Policy Based Management (PBM) is one of the greatest features shipped with SQL Server 2008. It made DBA’s life easier when it comes to implementation, compliance as well as changing any database/ server properties, especially when you need to implement /check some database / server settings across the databases/ servers. Recently, we have implemented Delayed durability database setting to Forced in one of our clients’ databases using Policy Based Management across the databases. Delayed durability is actually one of the best features shipped with SQL Server 2014. What made it best actually is its handling vs performance. You can just enable with a single statement and you get a huge performance boast.

 Note: Delayed durability is disabled by default. 

In this article, I will show you step by step, how to implement any database / server settings across the databases / servers using few clicks with the help of Policy Based Management.

Step 1:
Open SQL Server Management Studio (SSMS) and Select Management >>Policy Management >>Conditions and right click on it to Select New Condition… as shown below.

PBM - Delayed Durability 1.0

Step 2:
Now, we are in condition building screen, so lets build the 1st condition and that is to check delayed durability in all user databases which is online ONLY. Given below is the configuration. Do not forget to give a proper name to this condition.

PBM - Delayed Durability 1.1

Step 3:
Lets repeat Step 1 and open the condition creation screen. This time we will create the condition to check database setting which is delayed durability=FORCED. Given below is the configuration.

PBM - Delayed Durability 1.2

Step 4:
Now we are done with the conditions, so the next step is to build the Policy. In order to build the policy you need to Select Management >>Policy Management >> Policies and right click on it to select New Policy… as shown below.

PBM - Delayed Durability 1.4

Step 5:
Now, we are in policy creation screen, here we need to give a proper Policy Name and then select the conditions created in Step 2 and Step 3 shown below in red and blue color border respectively.  In  other words, we are trying to make policy which checks the delayed durability is forced or NOT in all user databases which is online.

PBM - Delayed Durability 1.6

Usually I choose the Evaluation Mode to “On Demand” showing above because it is the easiest way to evaluate and fix any discrepancy across the databases / servers, however, you can select On Schedule as well and Press OK.

Step 6:
Now, the policy has been created and you can see it under policies as shown below. Just right click on and select Evaluate to evaluate the policy as shown below.

PBM - Delayed Durability 1.7

Step 7:
You are in evaluation screen and you can see all the user databases shows in red color because none of them is having database settings to delayed durability= force.

PBM - Delayed Durability 1.8

Step 8:
Lets click on View Details to see the difference in database settings as shown below. You can see that Policy is expecting the Delayed durability = force but the actual value is disabled.

PBM - Delayed Durability 1.9

Step 9:
Lets select the databases where you want to change the database settings of delayed durability to FORCE and press Apply button. It gives the given below messages. Press YES button.

PBM - Delayed Durability 1.10

Step 10:
Once the policy has been implemented, policy based management will automatically evaluate the policy again and shows as green color icon as shown below.

PBM - Delayed Durability 1.11

Let me know if you have implemented any databases / servers settings using Policy Based Management.

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Sometimes, it is very important to know when your database has been dropped as well who dropped it. Obviously, if you setup the database backup properly, you can easily recover it from the last backup but how to find who dropped/ deleted the database ? Today, I came across this issue and I started my research and found some solutions to recover this info using trace, however, I developed a script that will help you find who dropped database, at what time, by using SQL Server Log.

Note : Please do not use this script for any negative purpose.

Script :

--This script is compatible with SQL Server 2005 and above.
USE master
GO
DROP PROCEDURE Recover_Dropped_Database_Detail_Proc
GO
CREATE PROCEDURE Recover_Dropped_Database_Detail_Proc
@Date_From DATETIME='1900/01/01',
@Date_To DATETIME ='9999/12/31'
AS
;WITH CTE AS (
Select REPLACE(SUBSTRING(A.[RowLog Contents 0],9
,LEN(A.[RowLog Contents 0])),0x00,0x) AS [Database Name]
,[Transaction ID]
FROM fn_dblog(NULL,NULL) A
WHERE A.[AllocUnitName] ='sys.sysdbreg.nc1'AND
A.[Transaction ID] IN (
SELECT DISTINCT [TRANSACTION ID] FROM  sys.fn_dblog(NULL, NULL)
WHERE Context IN ('LCX_NULL') AND Operation IN ('LOP_BEGIN_XACT')
AND [Transaction Name] LIKE '%dbdestroy%'
AND CONVERT(NVARCHAR(11),[Begin Time]) BETWEEN @Date_From AND @Date_To))

SELECT
 A.[Database Name]
,B.[Begin Time] AS [Dropped Date & Time]
,C.[name] AS [Dropped By User Name]
FROM CTE A
INNER JOIN fn_dblog(NULL,NULL) B
ON A.[Transaction ID] =B.[Transaction ID]
AND Context IN ('LCX_NULL') AND Operation IN ('LOP_BEGIN_XACT')
AND [Transaction Name] LIKE '%dbdestroy%'
INNER JOIN sys.sysusers C ON B.[Transaction SID]=C.[Sid]

GO
EXEC Recover_Dropped_Database_Detail_Proc
GO

1

Let me know if you came across this issue and its solution as well.

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On 26th May, we had a very informative session presented by Mr. Mohammed Owais (CTO at CAZAR) in SQL Server User Group meetup about Backups – not as simple as you think. He covered almost each and every aspect from full backup till tail log backup, however, a very nice question has been raised by an audience – ‘how to check the status of the backup / recovery along with the percentage via TSQL ?’. Because in most cases we have more than one DBA in an organization and sometimes they are geographically dispersed and if one of them takes backup / restore, how the others will come to know that he is performing any backup / restore using T-SQL.

Given below is the script which will give you the backup / restore progress along with the exact percentage and the user name (who is taking the backup).

USE master
GO
SELECT
  A.session_id As [Session ID]
, login_name As [Login Name]
, [command] As [Command]
, [text] AS [Script]
, [start_time] As [Start Time]
, [percent_complete] AS [Percentage]
, DATEADD(SECOND,estimated_completion_time/1000, GETDATE())
as [Estimated Completion time]
, [program_name] As [Program Name]
FROM sys.dm_exec_requests A
CROSS APPLY sys.dm_exec_sql_text(A.sql_handle) B
INNER JOIN sys.dm_exec_sessions C ON A.session_id=C.session_id
WHERE A.command in ('BACKUP DATABASE','RESTORE DATABASE')
GO

1 : While Taking Backup

USE master;
GO
BACKUP DATABASE AdventureWorks2012
TO DISK = 'C:\Data\AdventureWorks2012.Bak'
   WITH FORMAT,
      MEDIANAME = 'SQLServerBackups',
      NAME = 'Full Backup of AdventureWorks2012';
GO

raresql-Backup-Restore.1.2

2 : While Restoring Backup

USE master;
GO
RESTORE DATABASE AdventureWorks2012
FROM DISK = 'C:\Data\AdventureWorks2012.BAK'
WITH NORECOVERY
GO

raresql-Backup-Restore.1.1

Let me know if you came across this issue and its solution as well.

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TRY_CONVERT is one of the new conversion functions shipped with SQL Server. This function converts expression from one data type to another data type. The beauty of this function is that if it fails to convert, it returns NULL value as a results and due to this functionality, it has an edge over CONVERT function. I started using this function wherever conversion required since SQL Server 2012, however, I received an error message this morning when I was trying to use TRY_CONVERT function in SQL Server 2014 as shown below.

Let me explain this error in detail :

Message Number: 195

Severity : 15

Error Message: ‘TRY_Convert’ is not a recognized built-in function name.

Error Generation:

Let me create a sample using TRY_Convert  function to demonstrate this error.

USE SampleDB
GO
SELECT TRY_CONVERT(datetime2, '12/31/2010') AS Result;
GO
SELECT @@VERSION
GO

Msg 195, Level 15, State 10, Line 5
‘TRY_CONVERT’ is not a recognized built-in function name.

Microsoft SQL Server 2014 – 12.0.2000.8 (X64)

Try_Convert .1.2

Ooopps…… I am unable to use TRY_CONVERT even though I am using SQL Server 2014 as shown above.

Resolution:

The resolution is very simple, actually, what you are trying to do is to use TRY_CONVERT function in one of the databases having compatibility less than 110 even though you are using SQL Server 2014. Lets fix this issue step by step.

Step 1: Check compatibility

USE SampleDB;
GO
SELECT compatibility_level
FROM sys.databases WHERE name = 'SampleDB';
GO
--OUTPUT

compatibility_level
——————-
100

(1 row(s) affected)

Step 2: Change compatibility
As you can see above the compatibility of the database is below 110, lets change it to enjoy the core functionality of SQL Server 2014.
Note : Test the compatibility change of your database on your test/development database first, before proceeding to production database.

USE master
GO
ALTER DATABASE SampleDB
SET COMPATIBILITY_LEVEL = 120;
GO

Step 3: Use TRY_CONVERT

USE SampleDB
GO
SELECT TRY_CONVERT(datetime2, '12/31/2010') AS Result;
GO
--OUTPUT

Try_Convert .1.1

Conclusion :

Remember, whenever you use NEW SQL Server functions that are compatible with specific versions / compatibility level, you MUST check the version/ compatibility before implementing those functions.

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SET NOEXEC is one of my favorite SET statements. I am sure, when I explain it in detail you will love it too. Mostly, we come across in situations when we need to execute batch SQL statements (insert, update, delete) on production databases for the deployment / troubleshooting etc. Sometimes due to the syntax error, some parts of the batch statements execute and the remaining DO NOT and it creates the mess/headache for you to correct the data. And you are left with no option, but to restore the latest backup and fix the script and execute it again.

The solution for this problem is SET NOEXEC. It actually compiles the SQL Query and validate the syntax. The best/fun part is that it DOES NOT EXECUTE the SQL Query. So even if SQL Query is having errors, it DOES NOT affect the data and you are SAFE.

Let me create a sample to demonstrate, how it works.
Sample :

USE AdventureWorks2014
GO
--DROP TABLE tbl_sample
--GO
--Create a sample table
CREATE TABLE tbl_sample
(
 [ID] INT,
 [Letter] VARCHAR(1)
)
GO
--Insert a record in the table
INSERT INTO tbl_sample VALUES (1,'A')
GO
--Browse the data
SELECT * FROM tbl_sample
GO

NoEXEC.1.1

Now, let me turn on the NOEXEC and execute few statements and view the result-set.

USE AdventureWorks2014
GO
-- SET NOEXEC to ON
SET NOEXEC ON;

--Update the table
UPDATE tbl_sample SET [Letter]='B' WHERE [ID]=1
GO
--Delete the table
DELETE FROM tbl_sample  WHERE [ID]=1
GO
-- SET NOEXEC to OFF
SET NOEXEC OFF;
GO

NoEXEC.1.2

The output shows Command(s) completed successfully. It seems, that it not ONLY compiles but executes as well. Lets browse and check the impact of above queries on the data.

USE AdventureWorks2014
GO
--Browse the data to check the impact.
SELECT * FROM tbl_sample
GO

NoEXEC.1.1

As you can see above, the SQL Statements (Update & Delete) DID NOT IMPACT sample table data because NOEXEC was TURNED ON. Hence, it is PROVED that it ONLY compiles the SQL Statements and gives you either an error or Command(s) completed successfully message but it DOES NOT execute SQL Statements.

Note : Once you compiled the statement, DO NOT FORGET to turn NOEXEC off.

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Paging became quite simpler & easy to script and manage by using OFFSET & FETCH NEXT keywords in SQL Server 2012 & above. I have written quite a detailed article earlier about it and implemented it in my most of the solutions wherever required. However, when you implement/use paging in your script, you face a big challenge, that is, to find the total number of records in that particular result-set.

Given below are the three methods which you can use to get the total row count from OFFSET / FETCH NEXT.
Before proceeding with the solutions, let me create a sample.

Sample :

USE AdventureWorks2014
GO
-- Create Sample Table Table
CREATE TABLE [dbo].[SalesOrderDetail](
[SalesOrderID] [int] NOT NULL,
[SalesOrderDetailID] [int] NOT NULL,
[CarrierTrackingNumber] [nvarchar](25) NULL,
[OrderQty] [smallint] NOT NULL,
[ProductID] [int] NOT NULL,
[SpecialOfferID] [int] NOT NULL,
[UnitPrice] [money] NOT NULL,
[UnitPriceDiscount] [money] NOT NULL,
[LineTotal] [numeric](38, 6) NOT NULL,
[rowguid] [uniqueidentifier] NOT NULL,
[ModifiedDate] [datetime] NOT NULL
) ON [PRIMARY]
GO

-- Insert bulk data into sample table
-- It may take few minutes depends upon the server performance
INSERT INTO [dbo].[SalesOrderDetail]
SELECT * FROM [SALES].[SalesOrderDetail]
GO 100

-- Verfiy the data
Select * from [dbo].[SalesOrderDetail]
GO

Method 1 : Using COUNT(*) OVER()

USE AdventureWorks2014
GO
DECLARE
  @PageSize INT = 10,
  @PageNum  INT = 1;

SELECT
  [SalesOrderID]
, [SalesOrderDetailID]
, [CarrierTrackingNumber]
, [OrderQty]
, [ProductID]
, [SpecialOfferID]
, [TotalCount]= COUNT(*) OVER()
FROM [dbo].[SalesOrderDetail]
ORDER BY SalesOrderID
  OFFSET (@PageNum-1)*@PageSize ROWS
  FETCH NEXT @PageSize ROWS ONLY;
GO
--OUTPUT

row count using Offset 1.1

Method 2 : Using Common Table Expression

USE AdventureWorks2014
GO
DECLARE
    @PageSize INT = 10,
    @PageNum  INT = 1;

;WITH Main_CTE AS(
	SELECT [SalesOrderID]
	, [SalesOrderDetailID]
	, [CarrierTrackingNumber]
	, [OrderQty]
	, [ProductID]
	, [SpecialOfferID]
	FROM [dbo].[SalesOrderDetail]
)
, Count_CTE AS (
	SELECT COUNT(*) AS [TotalCount]
	FROM Main_CTE
)
SELECT *
FROM Main_CTE, Count_CTE
ORDER BY Main_CTE.SalesOrderID
    OFFSET (@PageNum-1)*@PageSize ROWS
    FETCH NEXT @PageSize ROWS ONLY
GO
--OUTPUT

row count using Offset 1.1

Method 3 : Using Cross Apply

USE AdventureWorks2014
GO
DECLARE @PageSize INT = 10,
        @PageNum  INT = 1;

 SELECT
  [SalesOrderID]
, [SalesOrderDetailID]
, [CarrierTrackingNumber]
, [OrderQty]
, [ProductID]
, [SpecialOfferID]
, [TotalCount]
FROM [dbo].[SalesOrderDetail]

CROSS APPLY (SELECT COUNT(*) TotalCount
FROM [dbo].[SalesOrderDetail] ) [Count]
ORDER BY SalesOrderID
OFFSET (@PageNum-1)*@PageSize ROWS
FETCH NEXT @PageSize ROWS ONLY
GO
--OUTPUT

row count using Offset 1.1

All of the above methods give you the same result-sets. Lets view their performance given below.

S.No

Method

CPU Time

Elapsed Time

1

COUNT(*) OVER()

30654 ms

40372 ms

2

Common Table Expression

11762 ms

7665 ms

3

Cross Apply

11794 ms

7373 ms

Conclusion :
On the basis of above results, I would recommend that you either use Common Table Expression or Cross Apply to get the faster results.

Note : The above queries have been tested on ~12 Million records.

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SQL Server 2014 is shipped with lots of exciting features and enhancements, which I usually share with you in my blog from time to time. Today, I will discuss a new enhancement that will minimize your code. This enhancement is actually in the CREATE TABLE (Transact-SQL). Now you can actually create NONCLUSTERED index within the create statement and you do not need to alter table to add NONCLUSTERED index anymore. However, if you want to follow the old method, you can continue doing it. The old method has NOT been discontinued.

Given below are both methods, demonstrating the enhancement.

NEW Method : (Create NONCLUSTERED index within the create table statement)
In this method, we will create NONCLUSTERED index within create table statement. This script is compatible with SQL SERVER 2014 and above.

USE AdventureWorks2014
GO
--DROP TABLE Employee
--GO
CREATE TABLE Employee
(
[Emp_ID] int NOT NULL,
[LastName] varchar(255) NOT NULL,
[FirstName] varchar(255),
[Address] varchar(255),
[City] varchar(255),
[PostalCode] nvarchar(15),
CONSTRAINT pk_Emp_ID PRIMARY KEY ([Emp_ID]),
INDEX IX_Employee_PostalCode NONCLUSTERED (PostalCode) 
);

GO
--OUTPUT

How to create a nonclustered index within the create table.1.1

OLD Method : (Create NONCLUSTERED index after creation of the table)
In this method, we will create NONCLUSTERED index AFTER table creation. This script is compatible with SQL SERVER 2005 and above.

USE AdventureWorks2012
GO
--DROP TABLE Employee
--GO
CREATE TABLE Employee
(
[Emp_ID] int NOT NULL,
[LastName] varchar(255) NOT NULL,
[FirstName] varchar(255),
[Address] varchar(255),
[City] varchar(255),
[PostalCode] nvarchar(15),
CONSTRAINT pk_Emp_ID PRIMARY KEY ([Emp_ID])
)
GO

CREATE NONCLUSTERED INDEX IX_Employee_PostalCode
ON dbo.Employee (PostalCode)
GO

How to create a nonclustered index within the create table.1.1

Conclusion
As you can see above, both methods will give you the same output, however, new method will reduce the line of code. Let me know your feedback about new enhancement.

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How to convert hexadecimal to binary became very interesting when I was trying to read SQL Server log. Most part of SQL Server log data is in Hexadecimal so you need to convert it from hexadecimal to multiple formats to read it properly. Generally, programmers use the hexadecimal table to convert it into binary. But I developed this solution using remainder method and used it in almost all my solutions, wherever I used SQL Server log. Given below is the script.

Script :

--DROP FUNCTION dbo.[UDF_Convert_Hex_to_Binary]
--GO
CREATE FUNCTION dbo.[UDF_Convert_Hex_to_Binary]
(
      @HEX VARBINARY(MAX)
)
RETURNS VARCHAR(MAX)
BEGIN

DECLARE @BINARY VARCHAR(MAX)

;WITH N1 (n) AS (SELECT 1 UNION ALL SELECT 1),
N2 (n) AS (SELECT 1 FROM N1 AS X, N1 AS Y),
N3 (n) AS (SELECT 1 FROM N2 AS X, N2 AS Y),
N4 (n) AS (SELECT ROW_NUMBER() OVER(ORDER BY X.n)
FROM N3 AS X, N3 AS Y)

SELECT @BINARY=ISNULL(@BINARY,'')
+ CONVERT(NVARCHAR(1), (SUBSTRING(@HEX, Nums.n, 1) / 128) % 2)
+ CONVERT(NVARCHAR(1), (SUBSTRING(@HEX, Nums.n, 1) / 64) % 2)
+ CONVERT(NVARCHAR(1), (SUBSTRING(@HEX, Nums.n, 1) / 32) % 2)
+ CONVERT(NVARCHAR(1), (SUBSTRING(@HEX, Nums.n, 1) / 16) % 2)
+ CONVERT(NVARCHAR(1), (SUBSTRING(@HEX, Nums.n, 1) / 8) % 2)
+ CONVERT(NVARCHAR(1), (SUBSTRING(@HEX, Nums.n, 1) / 4) % 2)
+ CONVERT(NVARCHAR(1), (SUBSTRING(@HEX, Nums.n, 1) / 2) % 2)
+ CONVERT(NVARCHAR(1), SUBSTRING(@HEX, Nums.n, 1) % 2) 

FROM N4 Nums
WHERE Nums.n<=LEN(@HEX) 

RETURN @BINARY
END
GO

Example :

Select dbo.[UDF_Convert_Hex_to_Binary](0x1cFEEE) AS [Hex to Binary]
GO
Select dbo.[UDF_Convert_Hex_to_Binary](0x2efd) AS [Hex to Binary]
GO
--OUTPUT

How to convert hexadecimal to binary.1.1

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SQL Server Management Studio is a handy tool that gives us the control to easily manage SQL Server. However, in Azure SQL Server, you can use its own query windows, where you can pass query against database. In today’s article, I will explain how to connect Azure SQL Server using your (on premises) SQL Server Management Studio (SSMS).

Pre-Requisite :

Given below is a step by step approach, demonstrating how to CONNECT Azure SQL using SSMS in simple steps.

Step 1 : (Create SQL Server in Azure)
First of all, you need to create/ setup a Server in Azure SQL Server using pre-requisite article.

Note : If you already have Setup Azure SQL Server, skip this step.

Step 2 : (Configure IP Address)
Once you have setup the Azure SQL Server in the above step, you just need to select that particular Server then further select Configure to add your local Server IP address from where you want to connect Azure using SSMS. This step is most important step because if you bypass this step and unable to add IP address of your local Server here, Azure will not allow your SSMS to connect Azure SQL Server.

Connect Azure SQL using SSMS.1.1

Connect Azure SQL using SSMS.1.2

Note : If you already configured the IP address of your local SQL Server machine, skip this step.

Step 3 : (Open SSMS)
Lets open SQL Server Management Studio and try to connect Azure SQL Server. Given below is the info that you must pass at the time of connectivity as shown below and Press Connect Button. Make sure your caps lock key should be turned on/ off accordingly ;).

Server Name : Azure SQL Server Name.database.windows.net (gx8icm0cm.database.windows.net)
Login : The login name which we created in pre-requisite article step 3.
Password : The password which we created in pre-requisite article step 3.

Connect Azure SQL using SSMS.1.3

Step 4 : (Azure SQL Server Connected in SSMS)
Now, you have connected Azure SQL Server using SQL Server Management Studio as shown below.

Connect Azure SQL using SSMS.1.4

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I presume this will be your first step towards Azure SQL Server and I am sure you will find this article as a guideline to proceed and create SQL Server & database in Azure.
Given below is a step by step approach, demonstrating how to create them using simple steps.

Step 1 : (Create Azure Account)
First of all, you need to create a Microsoft Azure account (it is free for one month ONLY, however it asks the credit card details for verification ONLY).

Free tial account of Azure.1.1

Note : If you already have Azure account, skip this step.

Step 2 : (Select SQL Databases)
Once you create the account and Sign in to Microsoft Azure, you will be in the Microsoft Azure portal as shown below. Here you can see a lot of different exciting features, however, you need to select SQL DATABASES from the left pane. Once selected, you will see sql databases dashboard on the right hand pane. In order to create a NEW SQL SERVER, you need to select SERVERS from top and press + button at the bottom as shown below.

Azure Create SQL Server & Database 1.1

Note : If you already have SQL Server, skip this step.

Step 3 : (Provide SQL Server Info)
Now you are in the SQL database server settings screen. Here you need to select the SUBSCRIPTION (if you have ONLY one then it will be selected by default), LOGIN NAME, PASSWORD and REGION (always select the nearest region which gives you the best performance) and press the CHECK MARK shown below.

Azure Create SQL Server & Database.1.2

Note : If you already have SQL Server, skip this step.

Step 4 : (SQL Server Creation)
Now, your server has been started creating and it generally takes 1-2 minutes.

Azure Create SQL Server & Database.1.3

Your server has been created as shown below.

Azure Create SQL Server & Database.1.4

Note : If you already have SQL Server in Azure account, skip this step.

Step 5 : (Select the Server)
Now, you need to select the SQL Server you just created in the above step. (If you already have a server, you can select it). Once you selected the server, it will take you to the SQL Server dashboard. Here you need to select the Create Database as shown below.

Azure Create SQL Server & Database.1.5

Step 6 : (Create Database)
You are now in the database creation screen, here, you need to specify database settings. You need to enter database name and choose the Service tiers, performance level, collation depending upon your requirement. Once you specify all the settings, you need to press CHECK MARK button as shown below.

Azure Create SQL Server & Database 1.6

Now, your database has been created as shown below.

Azure Create SQL Server & Database 1.7

Azure Create SQL Server & Database 1.8

Let me know if you have created your first SQL Server & database in Azure and your feedback about it.

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