Hi :) So in the editing can you change the direction? or rather the way that the relationships works? Regards from Tom :)
>________________________________ > From: Girvin R. Herr <[email protected]> >To: Tom Davies <[email protected]> >Cc: Dan Lewis <[email protected]>; "[email protected]" ><[email protected]> >Sent: Thursday, 10 January 2013, 21:44 >Subject: Re: [libreoffice-users] Re: Base scenario > >Tom, >Yes. I confirmed that right-clicking on a join line does allow deleting or >editing. >If I understand you correctly, no, relationship definitions should not be part >of the back-end. The table relationship is defined for the back-end by the >front-end through the SQL statements. For example, I have a table of >suppliers, with names and addresses and other contact information. This table >is related to almost all of my database (main) tables. Additionally, each >"main" table has its own set of table relationships with other (sub?) tables, >most of which are for selecting options with a join. Each record of these >option tables contains a primary key and a text field for the option. For >example, I have a table of statuses for the item in the main table record. An >integer foreign key in the main table contains a primary key value >corresponding to the text element of the statuses table record. That way, I >am only storing an integer (key value) in the main table, rather than the >option text, and with no repeated option text. It also standardizes the option texts. All of these multiple relationships must be defined by me - ergo it needs to be in the front-end. >Hope this helps clarify this. >Girvin Herr > > > >Tom Davies wrote: >> Hi :) >> Can you right-click on a relationship's join-line and edit it's properties? >> Shouldn't the relationships be part of the back-end rather than defined in >> the front-end? Regards from >> Tom :) >> >> >> >> >> >>> ________________________________ >>> From: Dan Lewis <[email protected]> >>> To: [email protected] Sent: Wednesday, 9 January 2013, 4:14 >>> Subject: Re: [libreoffice-users] Re: Base scenario >>> >>> Comment inline below. >>> >>> --Dan >>> >>> On 01/08/2013 07:07 PM, Girvin R. Herr wrote: >>> >>>> Ian, >>>> Have you actually drawn any relationships? Base will not do that for you. >>>> Just adding the tables in the 'Relationships Window' will not create the >>>> relationships automagically. You must click and hold on the one table >>>> element (remote key) and drag over to the related table's element (primary >>>> key), then release the mouse button. Base will then draw a line between >>>> the two. Note, the order of the drag is important. It determines the >>>> type of join. Joins are confusing to me too, so I can't help much there. >>>> I had to experiment with the direction to get it to work right. I think >>>> it was remote key to primary key, but I am not sure of that any more. >>>> >>>> Warning! The way the SQL language is set up, if either of the ends of a >>>> join (relationship) is NULL, then the record will be discarded and not >>>> show up in your result set. No warnings, no errors. Data records will >>>> just be missing. IMHO, this is stupid (my mantra is: "thou shall not lose >>>> data"), but that is how the SQL language was set up. So, make sure any >>>> joined data elements in all of your table records are not NULL. Note that >>>> NULL is not zero (0) and vice-versa! NULL means that there is no data in >>>> the record element. I use a lot of remote keys in my database main tables >>>> that point to primary keys (options) in other tables. In those other >>>> tables, I have made it a point to make the data elements of the first >>>> record to be "-", which is my equivalent of unknown, just to have >>>> something to select that is not NULL. You could probably use a blank (" >>>> "), but I prefer seeing the "-" in forms and reports. Most times in >>>> reports, it is hard >>>> >> to see anyway. Seeing the "-" tells me the field is not NULL. >> >>>> Hope this helps. >>>> Girvin Herr >>>> >>>> >>> These statements about joins do not seem to be quite correct. What >>>you are describing is an Inner Join: you will only see the rows of data in >>>which both the foreign (remote) key and the primary key have a value. >>> Suppose we have two tables A and B and that the foreign (remote) key >>>is in table A and the primary key is in table B. >>> Example 1: table A Left Outer Join table B. The output (result set) for >>>this contains all the fields in table A and their values on the left side of >>>the combined table. The right side contains all the fields in Table B. The >>>rows in which the primary key value matches the foreign key value, data from >>>both table appear in the output. However, where there is no primary key >>>value in table B that matches the foreign key value in table A, all the >>>fields from table B for that row will be NULL. >>> Example 2: table A Right Outer Join table B. The output for this >>>contains all the fields in table B and their values on the right side. For >>>each output row in which the foreign key does not have a value that matches >>>any value of the primary key, the fields in the left side of it will be NULL. >>> Example 3: table A Cross Join table B. This is also referred to as a >>>Cartesian Product. In this case, each row of table A is joined to all the >>>rows of table B. This contains all of the possible combinations of combining >>>both tables. Usually, some rows of the output will have the table A fields >>>all showing NULL while others will have the fields of table B showing all >>>NULL. >>> >>> >>>> Ian Whitfield wrote: >>>> >>>>> Hi All >>>>> >>>>> Re - My previous post.... Have been doing some Googling etc and found the >>>>> 'Relationships Window' for setting Relationships. >>>>> >>>>> I can get the Window up, select my Tables but it _DOES NOT_ draw any >>>>> connecting lines or set any Relationships!!?? >>>>> >>>>> Is this another "Gotcha" of using MySQL and Base together? As it does >>>>> _NOT_ seem to work at all!! >>>>> >>>>> I'm using PCLinuxOS 2012, LO Base 3.6.2.2 and MySQL 5.1.55 >>>>> >>>>> IanW >>>>> Pretoria RSA. >>>>> >>>>> >>> -- For unsubscribe instructions e-mail to: [email protected] >>> Problems? >>> http://www.libreoffice.org/get-help/mailing-lists/how-to-unsubscribe/ >>> Posting guidelines + more: http://wiki.documentfoundation.org/Netiquette >>> List archive: http://listarchives.libreoffice.org/global/users/ >>> All messages sent to this list will be publicly archived and cannot be >>> deleted >>> >>> >>> >>> >>> > > > > -- For unsubscribe instructions e-mail to: [email protected] Problems? http://www.libreoffice.org/get-help/mailing-lists/how-to-unsubscribe/ Posting guidelines + more: http://wiki.documentfoundation.org/Netiquette List archive: http://listarchives.libreoffice.org/global/users/ All messages sent to this list will be publicly archived and cannot be deleted
