This document really needs to be updated with more fleshed out information about primary keys, interrelationships, and maybe some nifty tables to document dependencies. Any takers?

Database Relationships Bugzilla database relationships chart

This information comes straight from my life. I was forced to learn how Bugzilla organizes database because of nitpicky requests from users for tiny changes in wording, rather than having people re-educate themselves or figure out how to work our procedures around the tool. It sucks, but it can and will happen to you, so learn how the schema works and deal with it when it comes. So, here you are with your brand-new installation of Bugzilla. You've got MySQL set up, Apache working right, Perl DBI and DBD talking to the database flawlessly. Maybe you've even entered a few test bugs to make sure email's working; people seem to be notified of new bugs and changes, and you can enter and edit bugs to your heart's content. Perhaps you've gone through the trouble of setting up a gateway for people to submit bugs to your database via email, have had a few people test it, and received rave reviews from your beta testers. What's the next thing you do? Outline a training strategy for your development team, of course, and bring them up to speed on the new tool you've labored over for hours. Your first training session starts off very well! You have a captive audience which seems enraptured by the efficiency embodied in this thing called "Bugzilla". You are caught up describing the nifty features, how people can save favorite queries in the database, set them up as headers and footers on their pages, customize their layouts, generate reports, track status with greater efficiency than ever before, leap tall buildings with a single bound and rescue Jane from the clutches of Certain Death! But Certain Death speaks up -- a tiny voice, from the dark corners of the conference room. "I have a concern," the voice hisses from the darkness, "about the use of the word 'verified'. The room, previously filled with happy chatter, lapses into reverential silence as Certain Death (better known as the Vice President of Software Engineering) continues. "You see, for two years we've used the word 'verified' to indicate that a developer or quality assurance engineer has confirmed that, in fact, a bug is valid. I don't want to lose two years of training to a new software product. You need to change the bug status of 'verified' to 'approved' as soon as possible. To avoid confusion, of course." Oh no! Terror strikes your heart, as you find yourself mumbling "yes, yes, I don't think that would be a problem," You review the changes with Certain Death, and continue to jabber on, "no, it's not too big a change. I mean, we have the source code, right? You know, 'Use the Source, Luke' and all that... no problem," All the while you quiver inside like a beached jellyfish bubbling, burbling, and boiling on a hot Jamaican sand dune... Thus begins your adventure into the heart of Bugzilla. You've been forced to learn about non-portable enum() fields, varchar columns, and tinyint definitions. The Adventure Awaits You!

If you were like me, at this point you're totally clueless about the internals of MySQL, and if it weren't for this executive order from the Vice President you couldn't care less about the difference between a bigint and a tinyint entry in MySQL. I recommend you refer to the MySQL documentation, available at MySQL.com . Below are the basics you need to know about the Bugzilla database. Check the chart above for more details. To connect to your database: bash# mysql -u root If this works without asking you for a password, shame on you ! You should have locked your security down like the installation instructions told you to. You can find details on locking down your database in the Bugzilla FAQ in this directory (under "Security"), or more robust security generalities in the MySQL searchable documentation. You should now be at a prompt that looks like this: mysql> At the prompt, if bugs is the name you chose in the localconfig file for your Bugzilla database, type: mysql use bugs;

Imagine your MySQL database as a series of spreadsheets, and you won't be too far off. If you use this command: mysql> show tables from bugs; you'll be able to see the names of all the spreadsheets (tables) in your database. From the command issued above, ou should have some output that looks like this: +-------------------+ | Tables in bugs | +-------------------+ | attachments | | bugs | | bugs_activity | | cc | | components | | dependencies | | fielddefs | | groups | | keyworddefs | | keywords | | logincookies | | longdescs | | milestones | | namedqueries | | products | | profiles | | profiles_activity | | shadowlog | | tokens | | versions | | votes | | watch | +-------------------+ Here's an overview of what each table does. Most columns in each table have descriptive names that make it fairly trivial to figure out their jobs. attachments: This table stores all attachments to bugs. It tends to be your largest table, yet also generally has the fewest entries because file attachments are so (relatively) large. bugs: This is the core of your system. The bugs table stores most of the current information about a bug, with the exception of the info stored in the other tables. bugs_activity: This stores information regarding what changes are made to bugs when -- a history file. cc: This tiny table simply stores all the CC information for any bug which has any entries in the CC field of the bug. Note that, like most other tables in Bugzilla, it does not refer to users by their user names, but by their unique userid, stored as a primary key in the profiles table. components: This stores the programs and components (or products and components, in newer Bugzilla parlance) for Bugzilla. Curiously, the "program" (product) field is the full name of the product, rather than some other unique identifier, like bug_id and user_id are elsewhere in the database. dependencies: Stores data about those cool dependency trees. fielddefs: A nifty table that defines other tables. For instance, when you submit a form that changes the value of "AssignedTo" this table allows translation to the actual field name "assigned_to" for entry into MySQL. groups: defines bitmasks for groups. A bitmask is a number that can uniquely identify group memberships. For instance, say the group that is allowed to tweak parameters is assigned a value of "1", the group that is allowed to edit users is assigned a "2", and the group that is allowed to create new groups is assigned the bitmask of "4". By uniquely combining the group bitmasks (much like the chmod command in UNIX,) you can identify a user is allowed to tweak parameters and create groups, but not edit users, by giving him a bitmask of "5", or a user allowed to edit users and create groups, but not tweak parameters, by giving him a bitmask of "6" Simple, huh? If this makes no sense to you, try this at the mysql prompt: mysql> select * from groups; You'll see the list, it makes much more sense that way. keyworddefs: Definitions of keywords to be used keywords: Unlike what you'd think, this table holds which keywords are associated with which bug id's. logincookies: This stores every login cookie ever assigned to you for every machine you've ever logged into Bugzilla from. Curiously, it never does any housecleaning -- I see cookies in this file I've not used for months. However, since Bugzilla never expires your cookie (for convenience' sake), it makes sense. longdescs: The meat of bugzilla -- here is where all user comments are stored! You've only got 2^24 bytes per comment (it's a mediumtext field), so speak sparingly -- that's only the amount of space the Old Testament from the Bible would take (uncompressed, 16 megabytes). Each comment is keyed to the bug_id to which it's attached, so the order is necessarily chronological, for comments are played back in the order in which they are received. milestones: Interesting that milestones are associated with a specific product in this table, but Bugzilla does not yet support differing milestones by product through the standard configuration interfaces. namedqueries: This is where everybody stores their "custom queries". Very cool feature; it beats the tar out of having to bookmark each cool query you construct. products: What products you have, whether new bug entries are allowed for the product, what milestone you're working toward on that product, votes, etc. It will be nice when the components table supports these same features, so you could close a particular component for bug entry without having to close an entire product... profiles: Ahh, so you were wondering where your precious user information was stored? Here it is! With the passwords in plain text for all to see! (but sshh... don't tell your users!) profiles_activity: Need to know who did what when to who's profile? This'll tell you, it's a pretty complete history. shadowlog: I could be mistaken here, but I believe this table tells you when your shadow database is updated and what commands were used to update it. We don't use a shadow database at our site yet, so it's pretty empty for us. versions: Version information for every product votes: Who voted for what when watch: Who (according to userid) is watching who's bugs (according to their userid). === THE DETAILS === Ahh, so you're wondering just what to do with the information above? At the mysql prompt, you can view any information about the columns in a table with this command (where "table" is the name of the table you wish to view): mysql> show columns from table; You can also view all the data in a table with this command: mysql> select * from table; -- note: this is a very bad idea to do on, for instance, the "bugs" table if you have 50,000 bugs. You'll be sitting there a while until you ctrl-c or 50,000 bugs play across your screen. You can limit the display from above a little with the command, where "column" is the name of the column for which you wish to restrict information: mysql> select * from table where (column = "some info"); -- or the reverse of this mysql> select * from table where (column != "some info"); Let's take our example from the introduction, and assume you need to change the word "verified" to "approved" in the resolution field. We know from the above information that the resolution is likely to be stored in the "bugs" table. Note we'll need to change a little perl code as well as this database change, but I won't plunge into that in this document. Let's verify the information is stored in the "bugs" table: mysql> show columns from bugs (exceedingly long output truncated here) | bug_status| enum('UNCONFIRMED','NEW','ASSIGNED','REOPENED','RESOLVED','VERIFIED','CLOSED')||MUL | UNCONFIRMED|| Sorry about that long line. We see from this that the "bug status" column is an "enum field", which is a MySQL peculiarity where a string type field can only have certain types of entries. While I think this is very cool, it's not standard SQL. Anyway, we need to add the possible enum field entry 'APPROVED' by altering the "bugs" table. mysql> ALTER table bugs CHANGE bug_status bug_status -> enum("UNCONFIRMED", "NEW", "ASSIGNED", "REOPENED", "RESOLVED", -> "VERIFIED", "APPROVED", "CLOSED") not null; (note we can take three lines or more -- whatever you put in before the semicolon is evaluated as a single expression) Now if you do this: mysql> show columns from bugs; you'll see that the bug_status field has an extra "APPROVED" enum that's available! Cool thing, too, is that this is reflected on your query page as well -- you can query by the new status. But how's it fit into the existing scheme of things? Looks like you need to go back and look for instances of the word "verified" in the perl code for Bugzilla -- wherever you find "verified", change it to "approved" and you're in business (make sure that's a case-insensitive search). Although you can query by the enum field, you can't give something a status of "APPROVED" until you make the perl changes. Note that this change I mentioned can also be done by editing checksetup.pl, which automates a lot of this. But you need to know this stuff anyway, right?