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create Dynamic columns in maria db using spring boot with jpa

I have using maria db to store dynamic columns.In sql Query it is there in the maria db documentation. https://mariadb.com/kb/en/library/dynamic-columns/ .
But i couldn't find a spring boot jpa implementation.I have tried jpa native query.I am storing a Json in this dynamic column which is data type of Blob in maria db.But it is very tough because i couldn't find a way to store when json is nesting another objects or arrays.Is there any way to accomplish this task

JSON is just a string. It could be stored in a TEXT or BLOB column.
The issue is that it is a structured string and it is tempting to reach into it to inspect/modify fields. Don't. It won't be efficient.
Copy values out of the JSON that you need for WHERE or ORDER BY (etc) so that MySQL/MariaDB can efficiently access them. Sure, keep copies inside the JSON text/blob, if you like.
Please describe your use for JSON, there may be more tips on "proper" usage inside a database.
That being said, MariaDB 10.2 has picked up much of Oracle's JSON. But there is not a JSON datatype. And there are a few function differences.
And this does not explain how far behind the 3rd party software (spring-boot, etc) is.

Store some data on server to access without a db

I want to store a little bit of data on my server that can be accessed easily by anyone. It's for a game I am making and I want to store a few things such as:
Game version (String)
Description (Long String)
News (Array of Strings)
Changelog (Array of Strings)
etc...
I figured that making a whole database and table for this would be overkill. I would like to be able to access the information using various types of media but I at least ant it to work with PHP (web) and Java (Desktop and android). Also the data will be updated and inputted manually by only me but readable publicly so that other websites can use it if they choose. What would I use for this kind of thing?
Extra: I might eventually want to input data manually. Things such as "Players Joined" would be managed by my server and would increment it automatically.So if it can do that too that would be great.

I have decided to use a Database and access the data with MySQL. I already have one for my game so it is a good choice because of that (this means I won't be creating a whole database just for this). I will create a table that will store this data and the table will only have 1 row (ID = 0). I will access it by selecting the row with ID = 0. I will have to create other tables with news and changelogs too.
If you have a similar question to mine, check this out:
http://www.dummies.com/how-to/content/storing-data-with-php-flat-file-or-database.html
It provided some useful advice. Also look into JSON or XML and SQLite.

You might want to check out H2 database. It can run as an embedded database (just include a jar, no extra installation, etc.), is very solid and you can get up and running very quickly.

How to Convert SQL table into Redis Data

Hi I am new to redis and want some help over here. I am using java and sql server 2008 and redis server. To interact with redis I am using jedis api for java. I know that redis is used to store key value based things. Every key has values.
Problem Background:
I have a table names "user" which stores data like id, name, email, age, country. This is schema of sql table. Now this table have some rows(means some data as well). Now here my primary key is id and its just for DB use Its of no use for me in application.
Now in sql I can insert new row, can update a row, can search for any user, can delete a user.
I want to store this tables data into redis. Then I want to perform similar operations on redis as well, like search, insert, delete. But if I have a good design on "Storing this info in DB and Redis" then these operations will be carried out simply. Remember I can have multiple tables as well. So should store data in redis on basis of table.
My Problem
Any design or info you can advise me that how I can convert DB data to Redis and perform all operations. I am asking this because I know Facebook is also using redis to store data. Then how they are storing data.
Any help would be very appreciative.

This is a very hard question to answer as there are multiple ways you could do.
The best way in my opinion would be use hashes. This is basically a nested a nested key-value type. So your key would match to the hash so you can store username, password, etc.
One problem is indexing, you would need to have an ID stored in the key. For example each user would have to have a key like: USER:21414
The second thing unless you want to look at commands like KEYS or SCAN you are going to have to maintain your own list of users to iterate, only if you need to do that. For this you will need to look at lists or sorted sets.
To be honest there is no true answer to this question, SQL style data does not map to key-value's in any real way. You usually have to do a lot more work yourself.
I would suggest reading as much as you can and would start here http://redis.io/commands and here http://redis.io/documentation.
I have no experience using Jedis so I can't help on that side. If you want an example I have an open-source social networking site which uses Redis as it's sole data store. You can take a look at the code to get some ideas https://github.com/pjuu/pjuu/blob/master/pjuu/auth/backend.py. It uses Python but Redis is such an easy thing to use everywhere there will not be that much to difference.
Edit: My site above no longer solely uses Redis. An older branch will need to be checked such as 0.4 or 0.3 :)

Content searching in a web application

I want to do a content search in my database. And the requirement is it has to be like a google search completely based on Ajax. Can you guys suggest me any framework or architecture or any kind of idea?
Example:
Employee Table contains Employee First Name, Last Name , Middle Name and Email. I have to search the table by providing any one of the field and the details of that employee should be populated

Consider using an index-based search engine. Apache Lucene is immensely popular, high-performant and well documented.

There are different parts to your question:
1) Ajax library: you could use Jquery which provides simple ajax methods http://api.jquery.com/jQuery.ajax/
2) On the server end there are a couple of options depending on the type of database youre using. Is it relational, is it nosql? Is your choice of database flexible or is it set in stone?
Lucene provides a query language for an index with more complex information and search requirements. But if your use case is as simple as the one above, you might just shoot off different SQL queries (assuming your database is relational).

how to create "has many" between two documents in couchdb?

basically I am wondering how you would go about in Couchdb as you would in MysQL: storing username, password in one table and link the user id as foreign key on another table of tasks?
should I just use mysql for the user authentication part and couchdb to store lots of user submitted documents? so create a random unique token to link each user to their "documents" on couchdb?
also I am looking to store Java objects to the couchdb, and retrieve them to be used directly in my application. which Java-couchdb library does this? Ektorp's example is seems more complicated compared to couchdb4j.

I do not know Java very well, but I suggest use the most simple tool you find. CouchDB is very simple and usually it is most beneficial to access it with simple tools too.
Yes, if you will have many relationships in the data, MySQL will help. However CouchDB can do some simple has-many queries.
First, there is view collation. You use map/reduce, and for every "child" document, you emit a key pointing to the parent document. When you query for ?key=parent then you get a long list of children. (The wiki explains it pretty well.)
Secondly, I suggest the article What's new in CouchDB 0.11 which shows how to use document _ids to link between two documents.
Good luck!