SQL PROGRAMMING STYLE- P28 potx

... at the time. Before you say that the NULL in SQL is a quick solution to this problem, think about how NULL is ignored in many SQL functions. The SQL query “SELECT tag_nbr, SUM(fine) FROM tickets ... allow for the change from the old ZIP codes to the current ZIP+4 codes in their address data. SQL does not have this as a physical problem, but it can show up as a logical problem. Ano...

Ngày tải lên: 06/07/2014, 23:20

... tables, 63 SQL 4GLs, 151, 152 bad programming in, 184–89 as declarative language, 193 Dynamic, 168–70 injection, 169–70 Standard, 4, 5, 6, 7, 118 testing, 130–31 thinking in, 183–95 SQL- 92 CASE ... 3 quoted identifiers, 5 string operators, 108 SQL- 99, 3 Stamp coupling, 156 Standard functions, 108 Standard Industrial Classification (SIC), 14 Standard SQL case-sensitivity rules, 6, 7...

Ngày tải lên: 06/07/2014, 23:20

... procedural programming! SQL will not make up for a lack of programming skills. In fact, the bad effects of mimicking 3GL languages in SQL are magnified. The optimizers and compilers in SQL engines ... reasoning. 10.1 Bad Programming in SQL and Procedural Languages As an example of not learning any relational approaches to a problem, consider a posting in the comp.databases...

Ngày tải lên: 06/07/2014, 23:20

... almost write itself. 9.2 Add the Words “Set of All…” in Front of the Nouns The big leap in SQL programming is thinking in sets and not in process steps that handle one unit of data at a time. ... still get multiple couples on the dance floor. This is where some experience with SQL helps. One of the customary programming tricks is to use a self-join to get a ranking of elements...

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: 06/07/2014, 23:20

... system, 89–90 Display, 96 Domain-Key Normal Form (DKNF), 62–63 DROP TABLE statement, 67 Dynamic SQL, 168–70 purpose, 168 in stored procedures, 169 E Electronic data interchange (EDI) files,

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

... 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

... used SQL/ PSM to mimic the classic COBOL program for this kind of summary. Without repeating a dozen columns again, a set-oriented solution is this: CREATE PROCEDURE SurveySummary() LANGUAGE SQL BEGIN DELETE ... original schema lacked keys and constraints that had to be added to give us this: 10.1 Bad Programming in SQL and Procedural Languages 187 but it at least follows the...

Ngày tải lên: 06/07/2014, 23:20