SQL PROGRAMMING STYLE- P6 pdf

... the count is redundant; SQL is orthogonal, and the scalar subquery can be used wherever the scalar variable is used. Rows are not records and columns are not fields. SQL is a declarative language, ... TIMESTAMP,—null means current CHECK(in_time < out_time), PRIMARY KEY (user_id, in_time)); Many new SQL programmers are scared of NULLs, but this is a good use of them. We do not...

Ngày tải lên: 06/07/2014, 23:20

... about Student Programming Practices,” Structured Programming , Fall 1989, p. 215. Celko, J. SQL for Smarties (3rd ed.). San Francisco: Morgan-Kaufmann, 2005. Celko, J. SQL Puzzles ... of Programming Style . Boston: McGraw-Hill, 1982. Ledgard, H. Programming Prover bs. Rochelle Park, NJ, Hayden Books, 1975. Ledgard, H., and L. J. Chmura. Fortran with Style:...

Ngày tải lên: 06/07/2014, 23:20

... tell what is good and what is bad in SQL. The procedural programmers had a deterministic environment in which the same program ran the same way every time. SQL decides how to execute a query ... front did not know this. Would you like to pick which four children will die because of sloppy programming? See what we mean by the last sentence in Ledgard’s quote? 9.6.2 Save Your First ....

Ngày tải lên: 06/07/2014, 23:20

... revolution and have reverted back to ad hoc programming but call it “extreme” or “agile” these days to make sloppy programming sound better. In classic structured programming, you have three control ... do, and it is why SQL is also known as a functional language. Procedural, communicational, informational, and functional cohesion are a bit more complicated in SQL than in 3GL pro...

Ngày tải lên: 06/07/2014, 23:20

... <table name > [BEFORE | AFTER | INSTEAD OF] [INSERT| DELETE | UPDATE] AS [< ;sql stmt> | BEGIN ATOMIC {< ;sql stmt>;} END] For obvious reasons, only one INSTEAD OF trigger per INSERT, ... Mullins calls catalog clutter . For example, in DB2, every unnecessary VIEW that is created in SQL will potentially insert rows into four VIEW-specific schema information table...

Ngày tải lên: 06/07/2014, 23:20

... I assume that you already write SQL at some level and want to get better at it. If you want to learn SQL programming tricks, get a copy of my other book, SQL for Smarties (3rd edition, ... Why would you believe people could become SQL gurus in a weekend? What they become is bad SQL programmers, who speak SQL in dialect from the local SQL product with a strong accent...

Ngày tải lên: 06/07/2014, 23:20

... Reserved Words 33 2.5 Avoid Proprietary Reserved Words if a Standard Keyword Is Available in Your SQL Product 33 2.6 Avoid Proprietary Statements if a Standard Statement Is Available 34 2.7 Rivers

Ngày tải lên: 06/07/2014, 23:20

... JOE CELKO’S SQL PROGRAMMING STYLE JOE CELKO’S SQL PROGRAMMING STYLE Joe Celko Publishing Director Michael Forster Publisher

Ngày tải lên: 06/07/2014, 23:20

... programmers. My goals in this book are to improve SQL programming style and proficiency. To be more exact: 1. To help an individual programmer write Standard SQL without an accent or a dialect . ... other SQLs, cannot be easily understood by an end user, and cannot be expanded. In the second case, what some newbies, who are still thinking in terms of second- and third-generati...

Ngày tải lên: 10/04/2014, 09:40

Ngày tải lên: 04/07/2014, 23:20