Primary keys are sorted to the top of the table symbols
Lines are thicker on hover to make it easier to select the relevant symbol
Query does not filter out empty tables.
This completes the set of databases that I have made this work for, might include DB2 at some point in the future if I ever work on an IBM system.
For this interactive version, hovering over the lines makes them larger so that you can click to highlight the line. This makes it easy to plan out a query by following the links between the relevant tables, regardless of where they are on the screen. A good example of this would be tracing out which language DVDs are rented out in a specified city? This needs seven tables and six relationships to determine this, and it is much easier to have the path highlighted while writing the query than having to remember the path as you write the query.
Posted by Pete McBreen Thu, 04 Aug 2016 02:45:00 GMT
In every iteration, have a few bugs that do not get fixed. After five or six iterations you can build up a reasonable size bug backlog without even trying, and the best bit is that you can hide them in the previous iterations so nobody important sees them.
If there is anything left over in the current iteration, move it into the next and increase the priority of that item.
Review all items that overflow into the next iteration to make sure that the team understands what is needed.
Publish the failure up the management chain if a defect survives to iterations.
Posted by Pete McBreen Sat, 19 Dec 2015 22:46:00 GMT
Recently as part of an archaeology task of understanding how some SQL queries were working, I needed to draw an ERD to help with my understanding of the database. After contemplating drawing the diagram by hand for a few seconds, I decided to leverage GraphViz and just draw a diagram of all of the foreign key relationships between the tables.
Since it was an Oracle database, the queries to read the relationships were not that complex ErdCrearion-specific.sql is designed to run in SQLDeveloper and prompt for the :OWNER tablespace name to pick the tables from, and limit the selection to the names mentioned in the tablelist CTE (unfortunately duplicated as I have not rewritten this to make it simpler).
gives us a nice image of the relationship. The table name is prefixed with the schema to make sure that you can identify the table correctly for those cases where the same table exists in multiple schemas, and the columns involved in the relationships are highlighted in their own box. The non-relationship columns appear at the bottom of the symbol (column ordering is maintained and hidden columns are not shown).
The resulting file when uploaded to a webserver that has d3.js in the right place is interactive - see scottsimple.html unlike the image above it can be clicked on to highlight the symbols or relationships - only the outer line of the table is clickable - the rest is left as an exercise for the reader.
Firefox has always had lots of really large extensions, but by deciding that they must be signed and reviewed, the Firefox community has just committed itself to a LOT of extra work reviewing the extensions. Hence the dumb idea of scanning to see if there is anything malicious in it. Now that is an arms race that is going to be lost. The guys in the AdBlock game know that, a continual game of whack a mole. Actively developed extensions like Zotero really lose out because a manual review of a large codebase takes a long time, and scanning is insufficient (as the above link describes, it is easy to create an add-on that passes scanning and does nasty things).
QA Engineer walks into a bar. Orders a beer. Orders 0 beers. Orders 999999999 beers. Orders a lizard. Orders -1 beers. Orders a sfdeljknesv.
I sure wish more programmers would focus a lot of attention on testing their own code before passing it on to QA/Test. That way the QA/Test team can focus on finding the requirements and interaction defects, rather than the simple coding mistakes that are often the bane of their existence
Posted by Pete McBreen Mon, 16 Feb 2015 02:49:00 GMT
Kevlin Henney - of Curly Bracket Languages fame has a good video of his presentation at a recent NDC conference Seven Ineffective Coding Habits of Many Programmers. As usual a very entertaining talk, but Kevlin is also spot on in identifying ways in which we are lead to make incorrect decisions about the code we are writing.
In it he references a paper from Rob Pike Notes on Programming in C. Although Rob Pike wrote that paper back in 1989 it is still relevant, as can be seen by his words about variable names:
Length is not a virtue in a name; clarity of expression is.