This study guide covers the internal workings of a basic SQL SELECT statement in Oracle. We'll focus on how the query retrieves data from a table and how it determines which rows to select. The query ...

This repository demonstrates how to unit test SQL queries in Python using unittest.mock to simulate a database. The SQL queries are read from .sql files, and the tests are designed to be isolated, ...

I have a table that logs a record containing a userid, a fileid and a date, one record inserted every time that file is downloaded.<BR><BR>I want to get the top 10 downloads by count for a given date ...

Query federation is a way to make use of distributed data sources on the Web, including many SPARQL endpoints as well as relational databases. SWObjects makes use of mapping rules represented as ...

SQL is neither the fastest nor the most elegant way to talk to databases, but it is the best way we have. Here’s why Today, Structured Query Language is the standard means of manipulating and querying ...

Read this SQL tutorial to learn when to use SELECT, JOIN, subselects and UNION to access multiple tables with a single statement. It’s sometimes difficult to know which SQL syntax to use when ...