Sql-server – What do these statements mean in the MS β exam 70-461 “skills measured” list

sql servert-sql

I have registered for the upcoming beta exam 70-461 entitled Querying Microsoft SQL Server 2012.

I've been reading through the exam overview and found a bunch of descriptions I'm not exactly sure what some of the items mean:

  • Create and alter DML triggers.
    • This objective may include but is not limited to: inserted and deleted tables; nested triggers; types of triggers; update functions; handle multiple rows in a session; performance implications of triggers
  • Query data by using SELECT statements.
    • This objective may include but is not limited to: use the ranking
      function to select top(X) rows for multiple categories in a single
      query; write and perform queries efficiently using the new code items
      such as synonyms and joins (except, intersect); implement logic which
      uses dynamic SQL and system metadata; write efficient, technically
      complex SQL queries, including all types of joins versus the use of
      derived tables; determine what code may or may not execute based on
      the tables provided; given a table with constraints, determine which
      statement set would load a table      ; use and understand different data
      access technologies; CASE versus ISNULL versus COALESCE

The problem here I think is with the wording, which I think I'm not able to fully understand.

If someone could clarify these I'd be most grateful.

To put it as an actual question:

What is Microsoft talking about on the above highlighted statements?

Best Answer

  1. DML - refers to data manipulation (update, insert, delete). A DML trigger is a trigger created to happen on update, insert or delete of table data.

The update function is the part of a DML trigger where you test if a required update has occured.

For Example:

CREATE TRIGGER myupdate_trigger
ON mytable
FOR UPDATE AS
if UPDATE(column_1)
BEGIN
-- Do something
END

This will trigger a further action every time column column_1 is updated in table mytable. The update function is UPDATE(column_1).

Related Question