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Oratable Oracle stuff worth talking about

English - Oracle, Sql, Databases
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Oratable · 3M ago

UNPIVOT in Oracle 11G to Select Columns As Rows

Sometimes we need to transpose columns as rows in SQL. Oracle 11G onwards, this requirement can be easily implemented using the UNPIVOT clause. A typical scenario: Customer data is validated...
Oratable · 3M ago

SQL to Select Rows Conditionally Based On Column Value

Let’s say a table contains multiple rows for an id. The requirement is to select only one of those rows, based on the value in a "type" column which determines the row’s priority. A typical ...
Oratable · 3M ago

ORA-12560: TNS:protocol adapter error

Sometimes you try to login to your Oracle XE on your home computer, and get this curt blocking response: Here’s the top reason why it might happen and how to fix it. Database is not up The f...
Oratable · 3M ago

ORA-01450: Maximum Key Length Exceeded – Possible Causes and Fix

ORA-01450 might crop up when a table index is being created in the database: ORA-01450: maximum key length (6398) exceeded Oracle documentation has this to say about the error: Cause: The co...
Oratable · 3M ago

I want to learn Oracle. Where should I begin?

Here is a simple guide to learning Oracle as a developer from scratch, on your own. For an absolute beginner to Oracle, it helps you navigate your way around the sea of information available...
Oratable · 3M ago

What are CBO and RBO?

In large applications that juggle tons of data, it isn’t enough to get a query to run without errors. The query must also perform well – get the results in fastest possible time, using the l...
Oratable · 3M ago

UTL_HTTP to Call a Web Service from PL/SQL

You can call a web service from within PL/SQL using the Oracle-supplied package UTL_HTTP. Here’s a demo of calling a public web service that returns latest city weather by ZIP. PL/SQL Script...
Oratable · 3M ago

UTL_FILE: Simple Write To File Example and Debugging Common Errors

A simple example of using UTL_FILE in PLSQL to create a file and write into it. Plus, the common ORA errors you encounter with the use of UTL_FILE, and how to resolve them. This script has b...
Oratable · 3M ago

SQL to Find Master Records with Identical Detail Records

The query to identify duplicate records in Oracle in a single table is fairly straightforward. Things get tricky in a two-table (master-detail) scenario, in which the master table holds the ...
Oratable · 3M ago

Replace Duplicates in ID Column with Unique Values

A common scenario: in the development environment, a table’s ID column is missing its unique key constraint, and developers have been creating their own data for testing. Suddenly someone re...