I have an Oracle database from which I am selecting a table from a remote postgres database, pg. The column mydate is of type date.
select to_char(mydate,'mm-dd-yyyy') from "pg_table"#pg
For the above query, I am getting an error like
ORA-02070: database PG does not support TO_CHAR in this context
*Cause: The remote database does not support the named capability in the context in which it is used.
*Action: Simplify the SQL statement.
Why is this happening?
Try to use to_date to first make it an oracle date then use to_char to transform
select to_char(to_date(mydate),'mm-dd-yyyy' ) as "Date"
from "pg_table"#pg
Some functions are not supported by the linked server driver to the backend server. I'm having this happen right now where regex_replace is not supported by links to MSSQL. This is just an unfortunate byproduct of using a linked server.
Related
Migrate a table from Oracle to SQL Server.
I have used Toad to export (select * from table) into a pipe delimited .txt file so it can be used to be consumed in SQL Server. Now the Oracle table has a DATE column and the output from Toad for that column is (2/26/2016 3.05.10.000000 PM). This format is not being compatible for the datetime column in SQL Server side.
I feel we can convert the date in Oracle to a compatible SQL Server format for easier ingestion.
Please help me understand the conversion both from Oracle to a compatible SQL Server format.
Create Oracle Linked server in SQL Server with ODBC connection. and use that Linked server to play with Oracle and SQL Server tables using SQL Server.
You must understand that DATE datatypes are binary data. Using to_date() on a column that is already a DATE is inappropriate. It forces oracle to perform (behind the scenes) a to_char() on the DATE column in order to produce character data that is the required input to to_date(). Then, when you see (in your text csv file) that it has produced a "date" in some particular format, it is because oracle has then had to run the result of your to_date() back through to_char(), using the default NLS_DATE_FORMAT setting to produce a character string for the text output.
So your solution is this:
First, determine what text format of a date MSSQL wants when it uses this csv file. I don't know what that is, but for the sake of argument, let's say it is 'yyyy-mm-dd'. With that information, construct your SELECT in oracle like this:
select mycol1,
to_char(my_date_col,'yyyy-mm-dd'),
mycol2
from my_table;
That said, I agree with the others, why bother with this cumbersome process in the first place? Or even some other intermediary like SSIS? Why not just create a shared server in MSSQL and query the oracle table directly? Or create a database link in the Oracle DB and, using the oracle transparent gateway as the conduit, INSERT directly into the MSSQL table from Oracle? Either the linked server or the database link will be much faster than any external process.
I would suggest a best way to transfer Oracle table to SQL Serveris by using SSIS package.
You can have a Source as Oracle and your conversion issue can be fixed by Data
Conversion task and your Destination can be SQL Server.
Is there any standard sql command that can show you the current RDBMS and version?
The reason for this question is that I am using a CMS remotely that use a SQL database, but I don't know which RDBMS is being used, so I thought maybe there is standard SQL command to print it, something similar to SQL server's ##version
This is not a direct answer to the question, but since there is no standard sql query or function to show the RDBMS, I will post the queries/functions/vars used to identify it.
-- SQL SERVER
SELECT ##version;
-- Postgres, mysql, mariadb
SELECT version();
-- Oracle
SELECT * FROM v$version;
-- sqlite
select sqlite_version();
Please pay attention that Mysql and Sqlite will show only the version and will not include engine name in contrast to other RDBMS.
I am using Oracle SQL Developer 4.1.3 and I have connected to MySQL database.
I want to select a different schema in Oracle SQL Developer but it is giving an error.
Here is my syntax:
ALTER SESSION SET CURRENT_SCHEMA = classicmodels;
I found this syntax on Docs.Oracle but still wondering why it is not working!
Thanks in advance!
I need to get a copy of a SQL Server 2008 table into an Oracle RDBMS. I have database link for SQL Server, database has a table which contains LONG BINARY type column.
When I issue
create table test_ora as select * from mssqltable#dblink
I get the error
Can't convert LONG
I tried to use to_lob, to_char, hextoraw and a ream of Oracle conversion function but still hasn't defeated the issue. Do you have any ideas?
p.s. I'm out of work now so can't tell exact ORA- error number.
There is a way to do that with undocumented Oracle's package:
http://tonguc.wordpress.com/2008/08/28/how-to-transfer-long-datatype-over-dblink/
I would recommend tool called Pentaho Data Integration. This is free, small and superb ETL tool.
Download page: community(.)pentaho(.)com
It will recreated all tables and types for you. How to do it:
pldwh(.)blogspot(.)co(.)uk/2013/03/pentaho-data-integration-create-tables_1(.)html
I never seen this, but is it possible to have one SQL call join data from Oracle and SQl Server?
Yes, Oracle and SQL Server both have functionality that allows to connect to other databases, including different vendors. In Oracle terminology, it's a database link instance while on SQL Server it's called a Linked Server instance.
The syntax to reference the instance is different between Oracle and SQL Server though. IE:
Oracle:
SELECT t.*
FROM table_name#database_link_instance t
SQL Server:
SELECT t.*
FROM linked_server_instance_name.database_name.schema_name.table_name t
does MySQL support the linked server concept?
No, the closest MySQL has is the FEDERATED engine, which is only for connecting to remote MySQL instances.
PostgreSQL?
PostgreSQL has dblink. Last time I looked at dblink (pre-v9 release), it only could connect to other PostgreSQL instances.
Yes- both Oracle and SQL Server support the linked server concept. That allows you to reference the other server using a 4 part name. For example:
select *
from LocalDb.Schema.Table
cross join
OracleLinkedServer.RemoteDb.RemoteSchema.RemoteTable