Intro to tsql unit 6

Uploaded on


More in: Technology
  • Full Name Full Name Comment goes here.
    Are you sure you want to
    Your message goes here
    Be the first to comment
    Be the first to like this
No Downloads


Total Views
On Slideshare
From Embeds
Number of Embeds



Embeds 0

No embeds

Report content

Flagged as inappropriate Flag as inappropriate
Flag as inappropriate

Select your reason for flagging this presentation as inappropriate.

    No notes for slide
  • 1
  • 45
  • 47


  • 1. Introduction To SQL Unit 6 Modern Business Technology Introduction To TSQL Unit 6 Developed by Michael Hotek
  • 2. Temporary Tables
    • Temp tables are used to hold intermediate result sets for further processing
    • These are used when you need to perform a process that can not be done in a single SQL statement
    • They come in two different types
    • local
      • accessible only to that connection
      • preceeded by a # ex: #authors
      • dropped when the session disconnects
    • global
      • accessible to all connections
      • must be explicitly dropped
      • preceeded by ## ex: ##authors
    • Names can only be 13 characters long
  • 3.
    • Temp tables can be a powerful addition to your code
    • They should be minimized at all costs
    • Many people overuse temp tables
      • Poor database design
      • Lack of SQL knowledge
      • Lazy
    • Temp tables can impose a significant drain on system resources
    Temporary Tables
  • 4. Select Into
    • Select into can be used to create a new table based upon a select statement
    • Creates the table to match the structure of the select list
    • Adds any data from the select
    • The database option select into/bulkcopy needs to be turned on
    • SELECT [ALL | DISTINCT] select_list [ INTO [ new_table_name ]] [FROM { table_name | view_name }[ ( optimizer_hints ) ] [[ , { table_name2 | view_name2 }[ ( optimizer_hints ) ] [... , { table_name16 | view_name16 }[ ( optimizer_hints ) ]]] [WHERE clause] [GROUP BY clause] [HAVING clause] [ORDER BY clause]
  • 5. Select Into
    • To create an empty table, include a where clause that will always be false
    • select * into temptitles from titles
    • where 1 = 2
    • It is highly recommended to do this and then insert the data into the table in a separate operation
    • Rules, defaults, constraints, indexes, triggers, etc. are not associated with the new table
    • Views are nothing more than a name for a select statement that is stored in the database
      • Behave exactly like a table
      • Do not store any data
      • May include more than one table
      • Simplify and/or customize data
      • Provides independence from the database schema
      • Provides security
    • The main factor in using security should usually be security
    • CREATE VIEW [ owner . ] view_name [ ( column_name [ , column_name ]... ) ] [WITH ENCRYPTION] AS select_statement [WITH CHECK OPTION]
    • Always explicitly specify the columns that will be included
    • With encryption means that the definition of the view is encrypted when it is stored
  • 8. With Check Option
    • The with check option restricts the data that can be inserted and updated through a view
    • Leaving this out, allows inserts and updates to the underlying data that might not show up in the view due to the where clause
    • When this is included, the insert and update must conform to the where clause of the view
  • 9. Restrictions
    • Another view can be included in the definition of a view, but only 16 tables/views can be emcompassed
    • Clauses not allowed
      • order by
      • compute/compute by
      • select into
    • Updates can be performed through a view as long as only one table at a time is updated
    • Updates can not be performed is a distinct, group by, or aggregate is included in the view
  • 10. Unit 6 Review
    • Temporary tables can be created to hold intermediate result sets
    • Temp tables are either local or global
    • Select into can be used to create either a permanent or temporary table
    • Views can be defined to provide alternate access to data
    • Views primary consideration should be security
  • 11. Unit 6 Exercises
    • Time allotted for exercises is 30 minutes