May 2019
Intermediate to advanced
484 pages
11h 23m
English
Content preview from Learn T-SQL Querying
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Using table variables and temporary tables
Table variables and temporary tables serve the same basic purpose: to store an intermediate resultset to be used by a subsequent query. Database developers use these to break down complex joined queries that typically are not very efficient.
We have mentioned before how the way a query is written can severely compromise SQL Server's ability to optimize a query efficiently in the little time it has to do it.
This means that a complex T-SQL query can be broken down into simpler T-SQL statements that store intermediate results before being used to join with other tables. Imagine a developer needs to build a query in the AdventureWorks sample database that returns the sales quota data by year for each ...
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