Download Advanced SQL Database Programmers Handbook by Donald K. Burleson, Joe Celko, John Paul Cook, Peter PDF

By Donald K. Burleson, Joe Celko, John Paul Cook, Peter Gulutzan

Show description

Read Online or Download Advanced SQL Database Programmers Handbook PDF

Best algorithms and data structures books

Information Extraction: Algorithms and Prospects in a Retrieval Context: Algorithms and Prospects in a Retrieval Context

Details extraction regards the approaches of structuring and mixing content material that's explicitly said or implied in a single or a number of unstructured info assets. It includes a semantic category and linking of definite items of knowledge and is taken into account as a mild type of content material figuring out via the computer.

Exploratory analysis of Metallurgical process data with neural networks and related methods

This quantity is worried with the research and interpretation of multivariate measurements often present in the mineral and metallurgical industries, with the emphasis at the use of neural networks. The e-book is basically geared toward the practising metallurgist or strategy engineer, and a substantial a part of it's of necessity dedicated to the elemental thought that is brought as in short as attainable in the huge scope of the sphere.

Extra resources for Advanced SQL Database Programmers Handbook

Sample text

The search conditions are logical predicates -- things that return TRUE, FALSE or UNKNOWN. But wait a minute, most programming languages work with Boolean logic and have only TRUE and FALSE logical values. SQL and Codd's first relational model have a thing called a NULL and it makes things ... interesting. The Null of It All A NULL is not a value; it is a marker for a value that is missing. SQL does not know why the value is missing -- semantics is your job. But SQL does have syntax to handle NULLs.

The dividend table must match exactly to the values of the divisor without any extra values. plane) = (SELECT COUNT(plane) FROM Hangar); This says that a pilot must have the same number of certificates as there planes in the hangar and these certificates all match to a plane in the hangar, not something else. The "something else" is shown by a created NULL from the LEFT OUTER JOIN. plane) because it does not work; it will tell you that the hangar has (n) planes in it and the pilot is certified for (n) planes, but not that those two sets of planes are equal to each other.

Com/oracle SQL NULL CHAPTER 5 Selection Introduction Continuing the look at basic relational operators and SQL, we get to an operation with an unfortunate name: Selection. Selection removes rows from a table which do not pass a search condition. It is the counterpart of Projection, which removes columns from tables. The reason the name is unfortunate is that SQL uses the keyword, SELECT, for the clause in a query that matches to the Projection operator and the keyword where for the clause in a query that matches to the selection operator.

Download PDF sample

Rated 4.78 of 5 – based on 24 votes