I'm new to flutter.
I want to sync local sqflite database from external mysql database. What is the best way
If I were you, I would create a function in Firebase Functions to send data from each table. And I would try to make the fields in both tables with the same names as much as possible as a way to facilitate maintenance
Related
I have a database where I have data of several enterprises.
The database is in Postgres.
Now I want a way to generate database backup with filtered data for each enterprises.
I have got a few solutions but is none of them data can be filtered, direct back up of database is possible but I want it filtered
What is the best way to do this? Is it possible?
I use postgresql. I have many databases in a server. There is one database which I use the most say 'main'. This 'main' has many tables inside it. And also other databases have many tables inside them.
What I want to do is, whenever a new row is inserted into 'main.users' table I wish to insert the same data into 'users' table of other databases. How shall I do it in postgresql? Similarly I wish to do the same for all actions like UPDATE, DELETE etc.,
I had gone through the "logical replication" concept as suggested by you. In my case I know the source db name up front and I will come to know the target db name as part of the query. So it is going to be dynamic.
How to achieve this? is there any db concept available in postgresql? Or I welcome all other possible ways as well. Please share me some idea on this.
If this is all on the same Postgres instance (aka "cluster"), then I would recommend to use a foreign table to access the tables from the "main" database in the other databases.
Those foreign tables look like "local" tables inside each database, but access the original data in the source database directly, so there is no need to synchronize anything.
Upgrade to a recent PostgreSQL release and use logical replication.
Add a trigger on the table in the master database that uses dblink to access and write the other databases.
Be sure to consider what should be done if the row alreasdy exists remotely, or if the rome server is unreachable.
Also not that updates propogated usign dblink are not rolled back if the inboking transaction is rolled back
I would like to know it will have any solution
Problem :
I have Cassandra database for saving large scale data from other sources continuously. Application-based data are saving in postgressql. For functionality, I want to query all data from postgresql. so I would like to save Cassandra data consistently to postgressql database based on data coming in Cassandra.
Is it possible?
Please suggest
I would like to save Cassandra data consistently to PostgreSQL database based on data coming in Cassandra.
There are no special utilities for this. You need to create your own service to gather data from Cassandra, process it and put results to PostgreSQL.
Sure. You can use Change Data Capture (CDC) to copy the data from Cassandra to PostgreSQL as and when there is a change in Cassandra data. One option is to use Kafka Connect with appropriate coonectors.
I have not found real sync from postgreSql to new graph database like neo4j, so I've decide to use same postgresql to sync one normalise tables with json table on the same postgresql with a differenta name for a database. So i have the best of two worlds, sql and nosql database.
When i see sql is more fast than graphql i can choose, and in the future, when i moved the nosql tables to a real graph database like neo4j and i ll be able to sync, i dont need to change the app that can use both database synced
Someone did already this? or it's a dumm idea? Or someone already use automatic libraries to sync from postgresql to neo4j ? and the another sens too ? or must I write sync scripts from scratch if i want to sync two databases?
I am new to the PostgreSQL database. What my visual c++ application needs to do is to create multiple tables and add/retrieve data from them.
Each session of my application should create a new and distinct database. I can use the current date and time for a unique database name.
There should also be an option to delete all the databases.
I have worked out how to connect to a database, create tables, and add data to tables. I am not sure how to make a new database for each run or how to retrieve number and name of databases if user want to clear all databases.
Please help.
See the libpq examples in the documentation. The example program shows you how to list databases, and in general how to execute commands against the database. The example code there is trivial to adapt to creating and dropping databases.
Creating a database is a simple CREATE DATABASE SQL statement, same as any other libpq operation. You must connect to a temporary database (usually template1) to issue the CREATE DATABASE, then disconnect and make a new connection to the database you just created.
Rather than creating new databases, consider creating new schema instead. Much less hassle, since all you need to do is change the search_path or prefix your table references, you don't have to disconnect and reconnect to change schemas. See the documentation on schemas.
I question the wisdom of your design, though. It is rarely a good idea for applications to be creating and dropping databases (or tables, except temporary tables) as a normal part of their operation. Maybe if you elaborated on why you want to do this, we can come up with solutions that may be easier and/or perform better than your current approach.