Contained Database in SQL Server

Contained Database is independent of the instance of the SQL Server on which it is hosted and also isolated from other databases.

SQL server 2012 allows the user to isolate the contained database in following ways

   1.       All the metadata is maintained in contained database instead of master database

   2.. All metadata are defined using same collation

   3.      User authentication is performed by database instead of the server login

in this way contained database becomes fully portable without having the issue of orphaned users.

Process to implement contained database:

1.  Enable setting for contained database authentication.

2. Create a Contained database named ContainedDB' by selecting containment type='Partial' in option tab.

3. Create database user named ContainedDBUser with SQL Server authentication with no link at instance level.

4. While connecting to containedDB database, connect it by selecting in options of 'connect to server' with the new user named ContainedDBUser.

Use master

GO

sp_configure 'show advanced options',1

GO

RECONFIGURE WITH OVERRIDE

GO

sp_configure 'contained database authentication', 1

GO

RECONFIGURE WITH OVERRIDE

GO

sp_configure 'show advanced options', 0

GO

RECONFIGURE WITH OVERRIDE

GO

Let us do it practically.

    1.       Create ContainedDB

   2.       In options tab select containment type to partial.

    3.       Create database user named ContainedDBUser with usertype as SQL USER WITH Password.

   4.       Connect to ContainedDB database using the above created user ContainedDBUser by mentioning details through options.

 in login mention ContainedDBUser

   5.       In connection properties tab, connect to database ContainedDB

66.       We will get ContainedDB connection as below.

f

     Please try above scenarios in Development environment only.

WITH RESULT SETS IN SQL Server

SQL server 2012 provide with result sets stored procedure execution facility through which we can have better control over the procedure output results, data types and column names.

/*Create Sample Employee Table */

CREATE TABLE Employee(EmpId int, Name Varchar(50),Salary Money)

/* Insert Sample Data in  Table Employee */

INSERT INTO Employee(EmpId,Name,Salary)

select 1,'Ram',100.5

UNION ALL

SELECT 2,'Shayam',115.5

UNION ALL

SELECT 3,'Sita',120

/* Check the inserted Data*/

SELECT * FROM Employee

Scenarios:

Example 1:

/*Create Stored procedure with complete result set*/

Create Procedure ProcEmployee

as

SELECT * FROM Employee

GO

execute ProcEmployee

with result sets

(

(EmployeeId Int, EmployeeName Varchar(1), Salary Int)

)

/*Output

After execution of above stored procedure with, with Result sets clause, it shows the out put column name and data types as per definition in with result sets clause

 */

Example 2:

Create Procedure ProcEmployee_withNoResult

as

SELECT * FROM Employee

where 1=2

GO

execute ProcEmployee_withNoResult

with result sets

(

(EmployeeId Int, EmployeeName Varchar(1), Salary Int)

)

/* OUTPUT

If we execute stored procedure with no result set and execute it with, with result sets clause it executes successfully with no error

*/

Example 3:

CREATE Procedure ProcEmployee_withPrint

as

PRINT 'PrintStmt'

GO

execute ProcEmployee_withPrint

with result sets

(

 ( EmployeeName Varchar(100) )

)

/* OUTPUT

If we execute SP without any result set have just print statement, it shows below error.

PrintStmt

Msg 11536, Level 16, State 1, Line 44

EXECUTE statement failed because its WITH RESULT SETS clause specified 1 result set(s), but the statement only sent 0 result set(s) at run time.

*/

Example 4:

CREATE PROCEDURE ProcEmployee_withZeroSelect

as

select top 0 0

GO

execute ProcEmployee_withZeroSelect

with result sets

(

 ( EmployeeName Varchar(100) )

)

/* OUTPUT

If we execute stored procedure with no result set and execute it with, with result sets clause it executes successfully with no error

*/

Example 5:

CREATE PROCEDURE ProcEmployee_withError

as

select 1/0

GO

execute ProcEmployee_withError

with result sets

( ( EmployeeName Varchar(100) ))

/* OUTPUT

If we execute stored procedure having error while execution, it shows below error

Msg 8134, Level 16, State 1, Procedure ProcEmployee_withError, Line 87

Divide by zero error encountered.

*/

Example 6:

EXECUTE dbo.ProcEmployee

WITH RESULT SETS UNDEFINED;

GO

/* OUTPUT: if we don’t want to change any output value or column we can use UNDEFINED clause

*/

Example 7:

EXECUTE dbo.ProcEmployee

WITH RESULT SETS NONE;

GO

/* OUTPUT: if we execute SP with NONE clause even though its returning data, it shows below error

Msg 11535, Level 16, State 1, Procedure ProcEmployee, Line 97

EXECUTE statement failed because its WITH RESULT SETS clause specified 0 result set(s), and the statement tried to send more result sets than this.

*/

Choose Function in SQL Server

Choose Function in SQL Server

Choose function pick the item located at specified index from the list of provided Values

Returns the data type with the highest precedence from the set of types passed to the function

Syntex:

CHOOSE ( index, val_1, val_2 [, val_n ] )

Examples: in the item list, we have varchar values, in our scenario we have 6 items['IT','India','Dinesh','Babu','Verma','Computer']

1.       If we pass index= 2 it will show value located at position 2

Select Choose(2     ,'IT','India','Dinesh','Babu','Verma','Computer')

2.       If we pass index=5.2(numeric) it will first convert into integer(5) and will show value located at position 5.

Select Choose(5.2  ,'IT','India','Dinesh','Babu','Verma','Computer')

3.       If we pass -Ve value, it will return NULL

Select Choose(-3.3  ,'IT','India','Dinesh','Babu','Verma','Computer')

4.       If we pass out of index value >6 then it will return NULL

Select Choose(9    ,'IT','India','Dinesh','Babu','Verma','Computer')

Scenario: in the list of provided items we should have same data type values Else it show error

Example:

Select Choose(3  ,'DB',5 ,'IT','India','Dinesh','Babu','Verma','Computer')

If we execute above statement it will show below error.

Msg 245, Level 16, State 1, Line 24

Conversion failed when converting the varchar value 'IT' to data type int.

Please try above in Dev Environment.