Beginner - 3 tables in 3 loops
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From: dsasorin via AccessMonster.com on 20 Mar 2010 20:51 Abki, please forgive me, but i don't understand your answer. Maybe because i'm a beginner in Access. I don't know how to join tables nor to manually writte a select. Maybe you get a picture for what i want to do, from my other answer to Gina Whipp. Thank you too. Abki wrote: >I hope u need data for all tables. > >1) You can go thru all tables and data with 1 loop if you do join all tables >in 1 singel select. > >2) If the select is manually written it can be like this: >SELECT * >FROM YEAR, > PLANT, > GENERATOR >WHERE PLANT.FK = YEAR PK > AND GENERATOR FK = PLANT.PK > >PK = Primary key, FK = foriegn key >You will have 1 row for each unik kombination. > >"dsasorin" skrev: > >> Hi ! >> >[quoted text clipped - 42 lines] >> >> . -- Message posted via AccessMonster.com http://www.accessmonster.com/Uwe/Forums.aspx/access-tablesdbdesign/201003/1
From: Gina Whipp on 20 Mar 2010 20:58 dsasorin, Okay, that didn't get me the answer needed, so let's try this... 1. Is a Powerplant always going to have the same Generator? 2. Do you put in dates when you enter the activities? 3. Where are the activities entered? 4. Where is the data you do the calculations on, is it in a table? You are concentrating on the how the data will look instead of how to store the data. It's like buying tires before you buy the vehicle. You need to buy the vehicle first... or build your tables first. -- Gina Whipp 2010 Microsoft MVP (Access) "I feel I have been denied critical, need to know, information!" - Tremors II http://www.regina-whipp.com/index_files/TipList.htm "dsasorin via AccessMonster.com" <u58852(a)uwe> wrote in message news:a5507a74f901c(a)uwe... The goal is to make a growing database (a programm) with inputs like year2010/powerplant 3/generator1/ .... or year 2012/powerplant7/generator3 and so on ... Then, the programm must have a simple user interface with those inputs. In the database tables i must asign diferent numbers (points) on specific tasks of the generator for example, and after a logical comparison and arithmetic calculations, it must result a number of points. So i need to input/select new data, to see/select old data, and after that i need a result (number of points) which coresponds to a certain ANSWER, introduced in the very beginning of the database (i.e. THE GENERATOR IS GOOD), also a table, i think. So, the purpose of the database is to find the state of the generator, based on the actions or the maintenance work made on each generator from database, and a new one. The criteria is based on those points and arithmetic calculations. Thank you for interest. Gina Whipp wrote: >dsasorin, > >Well, at least one of those tables is wrong and you are missing one, >possibly two tables. I am not totally clear what you are doing but I can >say this... it seems odd that you need a table for years. Sounds like you >need a *joiner* table. > >tblPowerPlants >pPowerPlantID (PK - Autonumber) >etc... > >tblGenerators >gGeneratorID (PK - Autonumber) >etc... > >tblPowerPlantGenerators >ppgPowerPlantGeneratorID (PK - Autonumber) >ppgPowerPlantID (FK - Long) >ppgGeneratorID (FK - Long) > >tblPowerPlantYears >ppgPowerPlantGeneratorID (FK - Long) >ppgYear (Combo Box with years) > >If you explain your purpose a little more it would help to give you a more >precise answer. I also don't understand the *looping*, what are the loops >for? Out of curiousity, what were the first lessons? > >Hi ! > >I am a beginner to databeses, and particulary to MS Access 2003. (althought >I >passed the first lessons) >I want to make a small database with possibility to grow up. (max. 100 >entries for a table) >I think that in my case the data must be structured like loop into loop. >Like that: > >Year: >2000 >2001 >2002 >2003 >etc. > > Plant: > plant_1 > plant_2 > plant_3 > etc. > > Generator: > gen_1 > gen_2 > gen_3 > etc. > >So for every Year it must exist some Power Plants, and for every Power >Plant >it must exist some Generators. >I already have made 3 tables: YEAR, PLANT, GENERATOR with data in it. >So, few questions arise: > >1. Is my algorithm any good (to consider 3 loops one in another for >database) >? >2. If my algorithm is good, how should it be done the relationship between >tables ? > >That is for start. Later i must make queries, input data, some logical >comparison, etc. >So i must do right from the beginning. I admit that my database must be >done >for 8 loops, not 3, but if i understand for 3, the same it will be for 8. > >Thanks in advance for help ! -- Message posted via AccessMonster.com http://www.accessmonster.com/Uwe/Forums.aspx/access-tablesdbdesign/201003/1
From: Gina Whipp on 20 Mar 2010 20:59 dsasorin, Oh okay.. was just curious. But it is interesting that you didn't mention Data Normalization and Data Modeling, do they teach that? -- Gina Whipp 2010 Microsoft MVP (Access) "I feel I have been denied critical, need to know, information!" - Tremors II http://www.regina-whipp.com/index_files/TipList.htm "dsasorin via AccessMonster.com" <u58852(a)uwe> wrote in message news:a55094019f828(a)uwe... I forgot that you put me a simple question. My first lessons were like this (Access 2003): What is a database ? The components of a database (the objects) How to sort data in tables ? and thinks like that ... Gina Whipp wrote: >dsasorin, > >Well, at least one of those tables is wrong and you are missing one, >possibly two tables. I am not totally clear what you are doing but I can >say this... it seems odd that you need a table for years. Sounds like you >need a *joiner* table. > >tblPowerPlants >pPowerPlantID (PK - Autonumber) >etc... > >tblGenerators >gGeneratorID (PK - Autonumber) >etc... > >tblPowerPlantGenerators >ppgPowerPlantGeneratorID (PK - Autonumber) >ppgPowerPlantID (FK - Long) >ppgGeneratorID (FK - Long) > >tblPowerPlantYears >ppgPowerPlantGeneratorID (FK - Long) >ppgYear (Combo Box with years) > >If you explain your purpose a little more it would help to give you a more >precise answer. I also don't understand the *looping*, what are the loops >for? Out of curiousity, what were the first lessons? > >Hi ! > >I am a beginner to databeses, and particulary to MS Access 2003. (althought >I >passed the first lessons) >I want to make a small database with possibility to grow up. (max. 100 >entries for a table) >I think that in my case the data must be structured like loop into loop. >Like that: > >Year: >2000 >2001 >2002 >2003 >etc. > > Plant: > plant_1 > plant_2 > plant_3 > etc. > > Generator: > gen_1 > gen_2 > gen_3 > etc. > >So for every Year it must exist some Power Plants, and for every Power >Plant >it must exist some Generators. >I already have made 3 tables: YEAR, PLANT, GENERATOR with data in it. >So, few questions arise: > >1. Is my algorithm any good (to consider 3 loops one in another for >database) >? >2. If my algorithm is good, how should it be done the relationship between >tables ? > >That is for start. Later i must make queries, input data, some logical >comparison, etc. >So i must do right from the beginning. I admit that my database must be >done >for 8 loops, not 3, but if i understand for 3, the same it will be for 8. > >Thanks in advance for help ! -- Message posted via AccessMonster.com http://www.accessmonster.com/Uwe/Forums.aspx/access-tablesdbdesign/201003/1
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