migration

问题 I'm writing a migration to add a column to a table. The value of the column is dependent on the value of two more existing columns. What is the best/fastest way to do this? Currently I have this but not sure if it's the best way since the groups table is can be very large. class AddColorToGroup < ActiveRecord::Migration def self.up add_column :groups, :color, :string Groups = Group.all.each do |g| c = "red" if g.is_active && is_live c = "green" if g.is_active c = "orange" g.update_attribute(

问题 I want to create a table in Laravel Migration like this- CREATE TABLE Payroll ( ID int PRIMARY KEY, PositionID INT, Salary decimal(9,2) CHECK (Salary < 150000.00) ); What I have done is- Schema::create('Payroll', function (Blueprint $table) { $table->increments('id'); $table->integer('PositionID '); $table->decimal('Salary',9,2); //$table->timestamps(); }); But I can't create this- CHECK (Salary < 150000.00) Can anyone please tell, how to implement this CHECK constraints in Laravel Migration

问题 Situation I have an OSGi project that I'm trying to migrate to Java 8. In my project, I have dependencies to third party libraries that I "OSGi-fied" (by just adding the MANIFEST.MF file and putting metadata into it). These libraries are checked out from read-only SVN repositories, so I just can checkout updates from then when needed and therefore I don't want to make any other changes than in the MANIFEST.MF file, since I cannot commit them. Problem However, these libraries use lots of

问题 Over on GitHub a helpful Google dev told me that to create a user session, your python backend server only needs a JWT library to verify the Firebase Auth token (signature and audience) in the request and extract the user info from the token payload. I am having trouble with verifying the token. This is where I'm at; In order to start the migration I proceeded as follows: I added Firebase-Auth to the Android App, while still having Gitkit in the App until Firebase-Auth works. Now I have two

问题 Over on GitHub a helpful Google dev told me that to create a user session, your python backend server only needs a JWT library to verify the Firebase Auth token (signature and audience) in the request and extract the user info from the token payload. I am having trouble with verifying the token. This is where I'm at; In order to start the migration I proceeded as follows: I added Firebase-Auth to the Android App, while still having Gitkit in the App until Firebase-Auth works. Now I have two

问题 Does any one know how to migrate data from one instance of Neo4j to another. To be more precise, I want to know, how to move the data from one instance of Neo4j on my local machine to another on remote machine. Does any one have any idea about it. I'm working on my windows machine with Eclipse and Embedded Neo4j . I need to transfer this data to remote Neo4j instance on a Centos machine. Please help me with this. 回答1: I found out the following workaround for copying the data from a server in

问题 Does any one know how to migrate data from one instance of Neo4j to another. To be more precise, I want to know, how to move the data from one instance of Neo4j on my local machine to another on remote machine. Does any one have any idea about it. I'm working on my windows machine with Eclipse and Embedded Neo4j . I need to transfer this data to remote Neo4j instance on a Centos machine. Please help me with this. 回答1: I found out the following workaround for copying the data from a server in

问题 I'm planning to convert a web app from using JSF managed bean to using CDI managed beans. I know I'll need to do below: Add a empty beans.xml file in WEB-INF. Replace all JSF @ManagedBean to CDI @Named annotations. Replace all JSF scope annotations with CDI or OmniFaces scope annotations. Replace all JSF @ManagedProperty with CDI @Inject annotations. Is that all that needs to be done? Are there any gotchas that I need to be aware of? 回答1: Basically, that's indeed all you need to do provided

问题 I have a metric table that I expect to be very large. It has a polymorphic association so that it can belongs_to other models that want to record some metric. I typically index association columns like this to speed up association loading. I've heard people talking about joint-indexing this association. This looks like: add_index :comments, [:commentable_type, :commentable_id] But I've also heard counsel against creating indexes of low-cardinality, because the payoff of the index doesn't

问题 Closed . This question is opinion-based. It is not currently accepting answers. Want to improve this question? Update the question so it can be answered with facts and citations by editing this post. Closed 5 years ago . so what I'm suggesting in my job, is to put db/schema.rb into .gitignore file, so we don't have (time to time) merging problems. There are some concerns that if something terrible happen (meteor fall from the sky right on the DB server and simultaneously all the db/migrete