SQL PROGRAMMING STYLE- P47 pdf

... 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

... Part I: Programming in PL /SQL Chapter 1. Introduction to PL /SQL Section 1.1. What Is PL /SQL? Section 1.2. The Origins of PL /SQL Section 1.3. So This Is PL /SQL Section 1.4. About PL /SQL Versions ... Resources for PL /SQL Developers Section 1.6. Some Words of Advice Chapter 2. Creating and Running PL /SQL Code Section 2.1. SQL* Plus Section 2.2. Performing Essential PL...

Ngày tải lên: 29/06/2014, 13:20

... > Page 423 A SQL* Plus Command Reference. SQLPLUS The SQLPLUS command is used from the operating system prompt to start SQL* Plus, and is discussed in Chapter 2, Interacting with SQL* Plus. SQLPLUS ... in a SQL* Plus script, and is described in Chapter 4. The double hyphen works the same way as REMARK, except that it may also be used in SQL statements and PL /SQL blocks. When use...

Ngày tải lên: 05/07/2014, 04:20

... those you find in other programming languages. This was very easy to avoid in Standard SQL- 92, since the language had no support for them. However, it is no longer true in SQL- 99, which introduced ... some physical dependence, but SQL is better than most programming languages on this point. 9. Logical Data Independence : This rule is also self-explanatory. SQL is quite goo...

Ngày tải lên: 06/07/2014, 09:20

... OVERLAPS predicate is a feature not yet available in most SQL implementations, because it requires more of the Standard SQL temporal data features than most implementations have. Many ... [NOT] BETWEEN <low value expression> AND <high value expression> is a feature of SQL that is used often enough to deserve special attention. It is also just tricky enough to f...

Ngày tải lên: 06/07/2014, 09:20

... theory) pick one column and use it. This fiction was needed because SQL- 89 defined subqueries as having only one column. Some early SQL implementations would work better with EXISTS(SELECT <column> ... random ordering of its rows, so that the SQL engine has to do a full-table scan. 14.2 Replacing ORs with the IN() Predicate A simple trick that beginning SQL programmer...

Ngày tải lên: 06/07/2014, 09:20

... Standard SQL syntax for the statement is: DROP VIEW <table name> <drop behavior> <drop behavior> ::= [CASCADE | RESTRICT] The <drop behavior> clause did not exist in SQL- 86, ... VIEW (they are allowed only on cursors in standard SQL) . This will force a sort and could materialize the VIEW as a working table. When the SQL engine has to do a sequential read o...

Ngày tải lên: 06/07/2014, 09:20

... If he had a total of two, he 19.2 Relational Division 413 19.2.5 Division with JOINs Standard SQL has several JOIN operators that can be used to perform a relational division. To find the pilots ... information to precompute the joins between tables. 19.2.6 Division with Set Operators The Standard SQL set difference operator, EXCEPT, can be used to write a very compact version of Dr....

Ngày tải lên: 06/07/2014, 09:20

... addition. MySQL 4.1 extended this function into the GROUP_CONCAT() function, which does the same thing but adds options for ORDER BY and SEPARATOR. This is handy when you use SQL to write SQL queries. ... SQL has the full SQL set of expressions, use this version: COALESCE (SUM((1.00 + P1.rate_of_return) * M1.day_N), 0.00) 21.6.2 The PRD() Aggregate Function by Logarithms Roy Har...

Ngày tải lên: 06/07/2014, 09:20