database-schema

问题 I have a PostgreSQL database for my Rails application. In the schema named 'public' the main Rails models tables are stored etc. I have created a 'discogs' schema which will have tables with names that are sometimes the same as in the 'public' schema - which is one of the reasons that I'm using schemas to organize this. How would I setup models from the 'discogs' schema in my app? I will be using Sunspot to let Solr index these models as well. I'm unsure of how you would do this. 回答1:

问题 How can I create a production database in Rails 3 and load a schema to it? I tried the following approaches... I. rake db:create Rails.env='production' && rake db:schema:load Rails.env='production' II. # config/environment.rb # Set the rails environment Rails.env='production' rake db:create && rake db:schema:load ... but neither of them works. Thanks. Debian GNU/Linux 5.0.6; Rails 3.0.0; Sqlite3 3.7.2. 回答1: You can set the rails env off of the environment variable RAILS_ENV RAILS_ENV

问题 How can I create a production database in Rails 3 and load a schema to it? I tried the following approaches... I. rake db:create Rails.env='production' && rake db:schema:load Rails.env='production' II. # config/environment.rb # Set the rails environment Rails.env='production' rake db:create && rake db:schema:load ... but neither of them works. Thanks. Debian GNU/Linux 5.0.6; Rails 3.0.0; Sqlite3 3.7.2. 回答1: You can set the rails env off of the environment variable RAILS_ENV RAILS_ENV

问题 This question already has answers here : MyISAM versus InnoDB [closed] (25 answers) Closed 6 years ago . MyISAM is designed with the idea that your database is queried far more than its updated and as a result it performs very fast read operations. If your read to write(insert|update) ratio is less than 15% its better to use MyISAM. InnoDB uses row level locking, has commit, rollback, and crash-recovery capabilities to protect user data. It supports transaction and fault tolerance above

问题 Is there some SQL that will either return a list of table names or (to cut to the chase) that would return a boolean as to whether a tablename with a certain pattern exists? Specifically, I need to know if there is a table in the database named INV[Bla] such as INVclay , INVcherri , INVkelvin , INVmorgan , INVgrandFunk , INVgobbledygook , INV2468WhoDoWeAppreciate , etc. (the INV part is what I'm looking for; the remainder of the table name could be almost anything). IOW, can "wildcards" be

问题 I'm building a web application for a printing company and am trying to determine the best design for my database. I have an orders table. Each order has many proofs. However, there are two different kinds of proofs: electronic proofs and physical proofs. Furthermore, if its an electronic proof, I need to store the image source, and if its a physical proof, i need to store a tracking number. Every proof has many comments associated with it. It would be nice if i could just have one proofs

问题 I have three tables: posts , post_tags and tags . One post can have many tags, and one tag can belong to many posts. Because of that many-to-many relationship, I made a post_tags table. It has two fields: p_id and t_id . They're both foreign keys to the posts table and tags table respectively. Now, when I run my PHP method to get the latest posts, I want to also retrieve the tags belonging to that post in one query. Just for reference, here's those three tables: posts | p_id | c_id | u_id |

问题 Due to the Nature of the Question , searching for similar questions or articles is quite difficult because keywords have a wide range of meaning. So if there is a similar question, pardon me. The Problem . (Simplified) I have a table of users. ( Table User ) Each user Has his own assets (Table Asset Foreign key to user Id) 2 Users can be cooperators. Each user selects the assets he wants to share with the other. For use in this cooperation a Shared Group Is created containing the assets of

问题 I have a mysql DB with 3 tables: - Campaigns id code name - Columns id name - Values id idColumn value The relationship beetween Campaigns and Columns is many to many: - ColumnsCampaign id idColumn idCampaign and the relationship beetween Columns and Values is one to many. I have this query that returns all values for each campaign: return Campaigns::addSelect('id','code','name') ->whereHas('typeCampaign', function ($q) use ($idTypeCampaign,$idMenu) { $q->where('typeCampaign.id',

问题 I'm looking for a design pattern to manage records in a relational database which belong together, e.g. grouping multiple contacts. The group itself does not need to be an entity. A group should have an unlimited count of members. It should be possible to run a query to get other group members of a given record. My idea is to manage it in one table: GROUPINGS integer group integer member_id primary_key (group, member_id) foreign_key (member_id) EDIT: Beware that group is not a foreign key. It