# Legacy databases and migrating **URL:** \ **Category:** Rails\ **Created:** [November 9, 2006, 12:53am UTC](https://www.ruby-forum.com/t/legacy-databases-and-migrating/75310 "2006-11-09T00:53:03Z")\ **Posts on this page:** 8\ **Page:** 1
**Author:** ![zanoni](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/z/e99b99/32.png) [@zanoni](https://www.ruby-forum.com/u/zanoni)\ **Post date:** [November 9, 2006, 12:53am UTC](https://www.ruby-forum.com/t/legacy-databases-and-migrating/75310/1 "2006-11-09T00:53:03Z")
Working on a project where the database will be migrated from MS SQL Server to MySQL. All fine, however the client is requesting that the schema remains the same. This means that table names are not pluralized and id is not just ‘id’ but the table name and id (i.e. table\_id) All in all it’s not a huge database, I’m looking at 30 tables total, but want to consider first the extra work I’ll have to do to make it all play together nicely. Any opinions ? and if I remember correctly from AWDWR the id column is probably not a big deal, but the singular table names disturb me. TIA Stuart – > **[Dark ambient](https://en.wikipedia.org/wiki/Dark_ambient)** > > Dark ambient (referred to as ambient industrial especially in the 1980s) is a genre of post-industrial music that features an ominous, dark droning and often gloomy, monumental or catacombal atmosphere, partially with discordant overtones. It shows similarities with ambient music, a genre that has been cited as a main influence by many dark ambient artists, both conceptually and compositionally. Although mostly electronically generated, dark ambient also includes the sampling of hand-pla > The te... ---
**Author:** ![zanoni](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/z/e99b99/32.png) [@zanoni](https://www.ruby-forum.com/u/zanoni)\ **Post date:** [November 9, 2006, 4:57am UTC](https://www.ruby-forum.com/t/legacy-databases-and-migrating/75310/2 "2006-11-09T04:57:21Z")
Stuart Fellowes wrote: > Working on a project where the database will be migrated from MS SQL > Server > to MySQL. All fine, however the client > is requesting that the schema remains the same. This means that table > names > are not pluralized and id is not just ‘id’ but > the table name and id (i.e. table\_id) > All in all it’s not a huge database, I’m looking at 30 tables total, but > want to consider first the extra work I’ll have to do to make > it all play together nicely. Any opinions ? > and if I remember correctly from AWDWR the id column is probably not a > big > deal, but the singular table names disturb me. > > TIA > Stuart > > – > [http://en.wikipedia.org/wiki/Dark\_amb](http://en.wikipedia.org/wiki/Dark_amb) Stuart, on the table names, here is a quote from page 191 of the Agile Rails book: "TheserulesreflectDHH’sphilosophythatclassnamesshouldbesingular whilethenamesof tablesshouldbeplural. If youdon’tlikethisbehavior, youcandisableit bysettingaglobal flaginyour configuration(thefile environment.rbintheconfigdirectory). ActiveRecord::Base.pluralize\_table\_names= false " (sorry about the wacky formatting there, Mac “Preview” or “Safari” bug I guess) best, jp ---
**Author:** ![zanoni](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/z/e99b99/32.png) [@zanoni](https://www.ruby-forum.com/u/zanoni)\ **Post date:** [November 9, 2006, 1:12pm UTC](https://www.ruby-forum.com/t/legacy-databases-and-migrating/75310/3 "2006-11-09T13:12:26Z")
In my case I made a small Ruby script who uses DBI interface. It keeps connection to old and new databases ( in may case that was the same flavor - PgSQL ) and recreates the model from legacy MixedCase way to RoR way, including data migration. This script somewhat generalized, but this is possible to do more generalization to make it possible to port from one DB flavor to other. PS: I spent few hours for that script and it saves me a days of hassle 🙂 All the Best! Sergey. ---
**Author:** ![zanoni](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/z/e99b99/32.png) [@zanoni](https://www.ruby-forum.com/u/zanoni)\ **Post date:** [November 9, 2006, 3:57pm UTC](https://www.ruby-forum.com/t/legacy-databases-and-migrating/75310/4 "2006-11-09T15:57:05Z")
Since I am always having to work with some old, legacy schema, I do this as a matter of course on all my model files: class MyClass \< ActiveRecord::Base set\_table\_name ‘whatevernameIwant’ set\_primary\_key ‘nameOfPrimaryKeyColNeedntBeid’ end Then you;re good to go. -Ralph ---
**Author:** ![zanoni](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/z/e99b99/32.png) [@zanoni](https://www.ruby-forum.com/u/zanoni)\ **Post date:** [November 9, 2006, 7:15pm UTC](https://www.ruby-forum.com/t/legacy-databases-and-migrating/75310/5 "2006-11-09T19:15:54Z")
Wait – Isnt MySQL not case sensitive (at least \<5.0, and I believe ---
**Author:** ![zanoni](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/z/e99b99/32.png) [@zanoni](https://www.ruby-forum.com/u/zanoni)\ **Post date:** [November 9, 2006, 5:07pm UTC](https://www.ruby-forum.com/t/legacy-databases-and-migrating/75310/6 "2006-11-09T17:07:18Z")
Ike wrote: > Since I am always having to work with some old, legacy schema, I do > this as a matter of course on all my model files: > > class MyClass \< ActiveRecord::Base > set\_table\_name ‘whatevernameIwant’ > set\_primary\_key ‘nameOfPrimaryKeyColNeedntBeid’ > end > > Then you;re good to go. -Ralph Not true. It works quite good for most of the cases but not all of them. If your column name starts with capital letter, then it starts to srew up a lot of plagins that expecting behavior like record.filedName or record.field\_name because in this case Ruby has conversation that if first letter is capital then it’s a constant. in this case you can get it only by record[‘FieldName’], so you see my point here. That was my reason to make a script that converts tables from MixedCase to lower\_case All the Best! Sergey. ---
**Author:** ![zanoni](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/z/e99b99/32.png) [@zanoni](https://www.ruby-forum.com/u/zanoni)\ **Post date:** [November 9, 2006, 7:19pm UTC](https://www.ruby-forum.com/t/legacy-databases-and-migrating/75310/7 "2006-11-09T19:19:54Z")
Ike wrote: > Wait – Isnt MySQL not case sensitive (at least \<5.0, and I believe > > > =5.0 that can be specified) so why not make them all be lowercase in your rails app? -Ralph Because I am using PostgreSQL, and this RDBMS is case sensitive. So the same can be true for other flavors such as Oracle. All the Best! Sergey. ---
**Author:** ![zanoni](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/z/e99b99/32.png) [@zanoni](https://www.ruby-forum.com/u/zanoni)\ **Post date:** [November 12, 2006, 1:29pm UTC](https://www.ruby-forum.com/t/legacy-databases-and-migrating/75310/8 "2006-11-12T13:29:40Z")
Sergey, Would you mind posting the script here, or is it proprietary? Thanks.