I have created Parent(Customer) and Child(Order)entity tables in the MySql database using hibernate and I have created one customer and some orders in those tables I can see those tables data in MySQL using MySql 8.0 command-line client but can't see on the database.
Could you please help me with the query?
Related
I have a project to migrate Oracle schema and its objects to SQL Server on SSMA.
I created a new table on the Oracle schema I am migrating, but I cannot see that table on SSMA.
I tried "Refresh from Database" on SSMA and it doesn't show up either. I receive the message: Nothing to process by this operation, because all objects are equal
When I open the schema on SQL Developer, I can see the table under the schema on Oracle
I have started working with mysql earlier, where different database meant completely different database, and I can create delete databases.
but when I started to working with oracle, the structure really confused me, the 'database' term means the same in Oracle as Mysql? If not whats the difference?
Thanks!
Oracle doc explain the difference (and migration tips):
2.2.5.1 Databases
When migrating MySQL databases to Oracle, SQL Developer maps each MySQL database to a tablespace in Oracle. Database objects, such as tables, indexes and views are stored in the respective tablespaces and are referenced from the Oracle schema for the user that owns them.
I have read that using Hive JDBC storage handler
(https://github.com/qubole/Hive-JDBC-Storage-Handler),
the external table in Hive can be created on different databases (MySQL, Oracle, DB2) and users can read from and write to JDBC databases using Hive using this handler.
My question is in the update .
If we use hive.14 where Hive update/delete is supported and use storage handler to point an external table to a JDBC database table, will it allow us to update the database table as well when we fire the update query from Hive end?
You can not update an external table in hive.
In hive only transcational tables support ACID properties. By default transactions are configured to be off. So to create transaction tables you need to add 'TBLPROPERTIES ('transactional'='true')' in your create statement.
There are many limitations to it. One of which is you cannot make external tables to be an ACID table because external tables are beyond the control of hive compactor.
To read more on this click here
I have postgres database on server A & oracle database on server B.
I would like to import the data of oracle to postgres using dbLink.
I have achieved this for Postgres to Postgres database, but now I would like to do this with oracle.
So
I have achived postgres to postgres migration with following command.
SELECT realestate.address, realestate.parcel, s.sale_year, s.sale_amount,
FROM realestate INNER JOIN
dblink('dbname=dbdelv port=5432 host=someserver
user=user password=pwd',
'SELECT parcel_id, sale_year,
sale_amount FROM parcel_sales')
AS s(parcel_id char(10),sale_year int, sale_amount int)
ON realestate.parcel_id = s.parcel_id;
How can I do the same for oracle? and what will be db Link?
dblink is for PostgreSQL only, it won't be able to connect to Oracle.
But you can use something that is even simpler, oracle_fdw, which is a foreign data wrapper for Oracle.
Download the code and follow the README to compile and install oracle_fdw.
Once you have created a foreign server and a user mapping, you can create a foreign table that will look and feel just like a normal PostgreSQL table, but the data reside in Oracle. You can use it in queries with joins like the one you showed in your question.
I'm using Birt 3.4.1. I was able to create a datasource.. but I can't see all the tables in my database. When I try to create a database I see 1/3 of my tables in the Oracle 10g database.
Are all the tables in the same schema?