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He has more than 7.6 years of experience in the software development. He has spent most of the times in web/desktop application development. He has sound knowledge in various database concepts. You can reach him at viki.keshari@gmail.com https://www.linkedin.com/in/vikrammahapatra/ https://twitter.com/VikramMahapatra http://www.facebook.com/viki.keshari

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Saturday, May 31, 2014

RULE II: Applying RULE on User Defined Data Type


Read Prev Article: A backward compatibility feature ‘RULE’ in SQL Server


RULES are constraint that bound to either column or User defined data type, they restrict the data entry to follow certain condition. They are quite different from Constraint which we will discuss in next series of article.

In previous article we saw, how we can create rule on Table Column, in this post we will see how we can create RULE on User Defined Data Type
                                  
Creating User Defined Data Type

create type phoone_number_type from varchar(13) not null
go

Creating Table using User Defined Data Type

create table PersonContacts
(pid int identity(1,1),
name varchar(10),
phone_number phoone_number_type)

Creating RULE

create rule phone_no_constraint
as
len(@phone) = 13 and
substring(@phone,3,1) = '-' and
isnumeric( left(@phone,2)) =1 and
isnumeric(right(@phone,10)) =1
Command(s) completed successfully.

Binding Rule to the column

exec sp_bindrule 'phone_no_constraint', 'phoone_number_type'
Rule bound to table column.

Now since Rules are bind to the column, lets try to insert value to the table. Here we have rule for Phone number is ’XX-XXXXXXXXX’ and X is integer type. Lets try to insert record against to Rule defined to Phone number and see what will be the result of insert.

insert into PersonContacts values('Neha','9820663556')
Msg 513, Level 16, State 0, Line 1
A column insert or update conflicts with a rule imposed by a previous CREATE RULE statement. The statement was terminated. The conflict occurred in database 'MyTest', table 'dbo.PersonContacts', column 'phone_number'.
The statement has been terminated.

An attempt to insert phone number not following Rules does not allow to insert record to the table.
Lets insert a proper record in the table.

insert into PersonContacts values('Lopa','91-9099956156')
(1 row(s) affected)

Let’s query the table to conform insertion.

select * from PersonContacts
pid         name       phone_number
----------- ---------- -------------
4           Lopa       91-9099956156

Unbind RULE

exec sp_unbindrule 'phoone_number_type'
Rule unbound from table column.

Drop Rule

drop rule phone_no_constraint
Command(s) completed successfully.

My enjoyment is my code, but u r taking over my space J
 

Post Reference: Vikram Aristocratic Elfin Share

Friday, May 30, 2014

A backward compatibility feature ‘RULE’ in SQL Server


RULES are constraint that bound to either column or User defined data type, they restrict the data entry to follow certain condition. They are quite different from Constraint which we will discuss in next series of article. Lets see how we can create RULE on column

Creating RULE

create rule phone_no_constraint
as
len(@phone) = 13 and
substring(@phone,2,1) = '-' and
isnumeric( left(@phone,2)) =1 and
isnumeric(right(@phone,10)) =1
Command(s) completed successfully.

Let’s create a table with a phone number field and check how we can assign Rule to the Phone number field.

create table PersonContacts
(pid int identity(1,1),
name varchar(10),
phone_number varchar(13))
Command(s) completed successfully.

Binding Rule to the column

exec sp_bindrule 'phone_no_constraint', 'PersonContacts.phone_number'
Rule bound to table column.

Now since Rules are bind to the column, lets try to insert value to the table. Here we have rule for Phone number is ’XX-XXXXXXXXX’ and X is integer type. Lets try to insert record against to Rule defined to Phone number and see what will be the result of insert.

insert into PersonContacts values('Snehal','9820663556')
Msg 513, Level 16, State 0, Line 1
A column insert or update conflicts with a rule imposed by a previous CREATE RULE statement. The statement was terminated. The conflict occurred in database 'MyTest', table 'dbo.PersonContacts', column 'phone_number'.
The statement has been terminated.

An attempt to insert phone number not following Rules does not allow to insert record to the table.
Lets insert a proper record in the table.

insert into PersonContacts values('Rinny','91-9099956156')
(1 row(s) affected)

Let’s query the table to conform insertion.

select * from PersonContacts
pid         name       phone_number
----------- ---------- -------------
3           Rinny      91-9099956156

Unbind RULE

exec sp_unbindrule 'PersonContacts.phone_number'
Rule unbound from table column.

Drop Rule

drop rule phone_no_constraint
Command(s) completed successfully.

Life without CODE is now happening…But oh my code, you are positive current to my love
 

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Thursday, May 29, 2014

Can we create Parameterized View in SQL Server?



SQL Server doesn’t have parameterized view but close to it they came up with Table Value User Defined Function in SQL Server 2000.

If it did exist, the syntax would be 

create view ParamterView
(@empName varchar(10))
AS
 select * from employee where emp_name like @empName
Msg 102, Level 15, State 1, Procedure ParamterView, Line 2
Incorrect syntax near '@empName'.
Msg 137, Level 15, State 2, Procedure ParamterView, Line 4
Must declare the scalar variable "@empName".

But unfortunately we don’t have luxury to create parameterized view like this.

But we have alternative approach to stimulate the same using Inline table value function

create function pv_studentInfo (@student_id int)
returns table
as
return
(
    select * from Student
    where id = @student_id
)
Go

Lets call this view using select statement.
select * from pv_studentInfo(1)
id          name
----------- ------------
1           vikram

(1 row(s) affected)

View offer performance benefit against Function by allowing indexes on it, where as you cannot create indexes on Function but yes you can wrap indexed indexed view in Function.

Your code silently induce oxygen to your business partner.
 

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