Versions of SQL differ somewhat from platform to platform to support specific features offered by a given database engine.
For example, in one database environment, you might reference a column value by adding a colon before the name of the column. In another, you might not need the colon. In addition, different database capabilities can help you determine the best approach to submitting your query.
Although you will not learn about many of the advanced features in this course, it is important to understand that you will need to do some basic research as you start working with your selected database engine. You will need to determine SQL Capitalization
SQL typically does not care about the capitalization in your queries.
Capitalization has been provided throughout this course to help make the content more readable.
If you find that you have spelled everything in your query correctly but it still returns no results or an error message indicating it cannot find what you are looking for, check with your database administrator and see if the database is set up to be case-sensitive.
Procedural Extensions
SQL is designed for a specific purpose: to query data contained in a relational database. SQL is a set-based, declarative query language, not an imperative language like C or BASIC. However, there are extensions to Standard SQL which add procedural programming language functionality, such as control-of-flow constructs.
These include:
In addition to the standard SQL/PSM extensions and proprietary SQL extensions, procedural and object-oriented programmability is available on many SQL platforms via DBMS integration with other languages. The SQL standard defines SQL/JRT extensions (SQL Routines and Types for the Java Programming Language) to support Java code in SQL databases. SQL Server 2005 uses the SQLCLR (SQL Server Common Language Runtime) to host managed .NET assemblies in the database, while prior versions of SQL Server were restricted to using unmanaged extended stored procedures that were primarily written in C. PostgreSQL allows functions to be written in a wide variety of languages including Perl, Python, Tcl, and C In the next lesson, the database will be implemented.
SQL Approaches - Quiz
Take this quick quiz to determine how well you understand the basics of SQL before moving on. SQL Approaches - Quiz