How to run conditional scripts based on the database in the flyway. For example, some script needs to run as the main script and some to be run on a specific database. Is it possible this way in the flyway?
My advice would be to save the target-specific scripts in a different subfolder (ie, a subfolder for each target) and when "migrating", specify flyway.locations differently depending on the target.
Related
I just started looking into Flyway using the command line route, and was wondering if it is possible to reuse the .sql file?
Example:
I have a file called V1__Create_user.sql which has
CREATE USER ${user_name} WITH PASSWORD '${pass}';
GRANT readaccess TO ${user_name};
It looks like I can only use this sql file once, that is when I run below command
flyway -placeholders.userName=test_user -placeholders.pass=test migrate
When I run the above command again with different user_name and password for the placeholders, no changes was made.
So, I was wondering if there's a way to reuse that sql file instead of generating new sql files containing the same sql query over and over ?
The way Flyway works is that it runs the scripts you provide it in the order in which you provide it. It puts a marker in the database showing which scripts it has already run. Then, when you rerun it, it will only run the scripts that it has not yet: run V2__Whatever, V2.2__Something, etc..
You can't go back & modify an existing script and expect the tool to pick up that it has changed and then rerun it. Even if that script is using placeholders.
That doesn't include the repeatable scripts (stuff like view definitions) that run every time you deploy using Flyway. If you had to, you could make that a repeatable script and run it that way. BUT, that will work as long as every deployment is incremental, 1 to 2, 2 to 3, 3 to 4. As soon as you need to deploy from version 1 to 4, you can't pass multiple commands in.
Since every instance of SQL in relational data stores I'm aware of is a declarative language, the best way to deal with it, is to use it as such. Yes, that means stuff like CREATE USER is used over & over. However, since each USER created is unique, that's just how it works.
I have a configure script to set up some paths for my R package during installation. I wish to edit a file based on some conditions. Is there any way to edit a file from within the configure.ac? It would be great if the solution is provided for all operating systems.
Is there any way to edit a file from within the configure.ac?
configure.ac is not executable, but I suppose you mean that you want the configure script generated from it to edit a file. The configure script is a shell script, and you can cause arbitrary shell code to be included in it, more or less just by including that code at the corresponding point in configure.ac.
The question, then, is how you would automate editing a file with a shell script. There is a variety of alternatives, but sed is high on my list. You will find it on every system that can support Autoconf configure scripts, because such scripts use it internally.
On the other hand, this sort of thing is one of the main activities of a configure script, in the form of creating files (especially makefiles, but not limited to those) from templates. You should consider building your target file of interest from a template in this way, instead of making custom-programmed edits to a file packaged in your program distribution. This would involve
setting output variables containing the chosen content for the parts of the file that need to be configured;
designating the target file as one for configure to build; and
providing the template, maybe by taking a complete example file and replacing each variable part with a reference to the appropriate #output_variable#.
Some teams in our company are currently "upgrading" some legacy projects to use Flyway. One problem is that there exists multiple installations with already available database objects (baseline).
We currently have (and definitely will have more in the future as well) a use case, where we have to create some new migration scripts, but they only should run when certain conditions about the current state of the database are met.
For example: run this script, but only if table X in the database contains data Y
I have already seend Flyway conditional db migration, but to me this doesn't seem like the right solution, since the condition isn't just some static environment. The condition if a migration should be executed or not should be dependent on the current live state of the database.
I myself have not much experience with Flyway, but more with Liquibase. There I would implement it like this:
<preConditions onFail="WARN">
<sqlCheck expectedResult="0">select count(*) from oldtable</sqlCheck>
</preConditions>
Is there an equivalent in Flyway?
To my knowledge, no, Flyway itself can't do this kind of conditional statement. However, since flyway just runs the scripts in order, put the conditional command within the deployment script and that will work. Flyway simply executes the scripts, so they can be customized as you need them to be.
Hello I wanted to ask if, to import the .sql update (after a git pull) I have to assemble and merge with the bash file (app/db_assembler) or if it's ok if I just launch the worldserver.exe and he will do it
Thanks
Short answer
No, the worldserver process will NOT update your database.
You need to use the DB-assembler bash script, as the instructions say.
More details
This is different than in TrinityCore, where it is a feature of the worldserver process to update the database.
In AzerothCore this task is a responsability of an external script, written in bash, the DB-assembler.
The advantage of having an external script to do this task instead of the worldserver is:
You don't need to compile and run the worldserver if you only need to create the database (useful when using or developing tools that only need the DBs)
The DB assembler is able to generate a unique SQL update file per each DB (by merging all the single SQL update files), which can be useful for debugging or development purposes
In general, it is better to delegate different software components for different tasks, instead of having a monolith doing everything
You can also make your own merge script and apply manually. Or just merge with the db_assembler.sh then apply manually.
Else refer to Francesco's answer
I use Scrum methodology and deploy functionality in builds every sprint.
There is necessity to perform different changes in the stored data (I mean data in database and on filesystem). I'd like to implement it as a PHP scripts invoked from console. But they should be executed only once, during the deployment.
Is there any way to implement it through app/console without listing it in the list of registered Console commands? Or is there any other way to implement runonce scripts?
DoctrineMigrations covers some part of my requirements, but it's hard to implement complex changes in Model. And it does not cover changes in files on the filesystem.
I don't think symfony has a facility for that, and besides, hiding the command is not the same as securing the command.
Instead, I would make the script determine if it has been run already (could be as simple as adding a version number to a file and checking that number before running) and stop if it detects it has already run before.