Re: Step 1 with Visual Basic - Mailing list pgsql-novice
From | Richard Broersma |
---|---|
Subject | Re: Step 1 with Visual Basic |
Date | |
Msg-id | 396486430806171814u5670108at2fa2685cbdaa478a@mail.gmail.com Whole thread Raw |
In response to | Re: Step 1 with Visual Basic (Gary <sql@4myad.tv>) |
List | pgsql-novice |
On Tue, Jun 17, 2008 at 4:58 PM, Gary <sql@4myad.tv> wrote: > > Sorry to be such a pest. If I could understand these documents I probably > wouldn't have to read them. I've been zipping around the net reading docs > but nowhere do they start at the beginning. Okay. Well, I'll try to give a little background information. PostgreSQL is a Relational Database Management System (RDBMS). Basically it purposed is to 1) implements and maintains physical data-patterns that were defined to by a users conceptual database design, 2) to safely accept and store data into the physical pattern, 3) return sets of data from the data pattern upon client request, 4) change the data (and sometimes the data-pattern ) that it stores. Note: A database data-pattern is usually referred to as a schema. The schema is an implementation of how a particular database works together as a whole. PostgreSQL is installed with several shell/MS-DOS based client programs that interact with PostgreSQL for the purposes of doing step 1 thru 4. The one that is most useful is psql (or psql.exe for a windows installation). However, psql purpose is mostly to achieve step 1. Now there is an important distinction that needs to be made between PostgreSQL and a Database. PostgreSQL is a RDBMS. While a database contains the physical implementation of a particular schema. Basically Postgresql gives the breath of life to a database. Another point to make about a database, is that a database is only as good as the Conceptual Design that it implements. A good analogy might be: PostgreSQL is to Microsoft Word, in the same way as a database is to a Word document, and continuing the illustration, the text of in a Word document is to a database Conceptual design/schema. The purpose of the conceptual design is to adequately model the reality of whose data one would want to store. This is necessary since the designer wants to capture not only the important aspects of the reality, but also how these aspects interrelate with one another. So to make a valid point. A person who has no sense of spelling or grammar should never expect to use MS-Word to create the worlds best novel or poetry. Also a person who has no sense of conceptual database design/ data modelling could ever expect to make a workable database. Not to say that this can't be done. But in either case the person must first learn the applicable skill for the task. Up to this point we've said nothing about how to access this database. And we've not mentioned how to do analysis on the data based upon the relationships the exists between the data in a particular database. This is where the Language of SQL comes into play. Lastly as Client front-end programs also want to access that database of the database. For the purpose of recording the important data of a particular reality( usually a business process ). The Client application needs to know information about the PostgreSQL Server (server ip, Postgresql ip port, Postgresql database of interest, the user and password that will be used to connect), the database ( the database schema(data model), all of the tables, constraints, views, indexes), and the SQL queries that it will use to efficiently interact with that database. > I've rediscovered how to start the interactive terminal and even listed the > commands. Might as well be in Chinese. I understand. If you read Chapters one and two it should answer mosted of the basic questions: http://www.postgresql.org/docs/8.3/interactive/tutorial-start.html > Seems like step 1 might be to determine the names of the data fields in the > database. (tables & ?). How do I do that? psql -U <yourdbusername> -d <databasename> # \dt --list all the table in the public schema # \d <a particular table name> -- see the columns of the table #\? -- where to look for other useful commands > Is there a newsgroup with "training wheels"? This is the correct mailing list. However, instead of asking broad vague questions. It is much better to ask many small specific questions to specific mailing lists. good questions example: -- I cant' connect using psql. It throwing this error. What do I do? -- I cant connect using ODBC. This is the error message when I try. bad question example: -- I don't get it. What do I do? Regards, Richard Broersma Jr. Visit the Los Angles PostgreSQL Users Group (LAPUG) http://pugs.postgresql.org/lapug
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