SQL Cross Apply and Outer Apply: The Complete Guide
Have you heard of the SQL Cross Apply feature but have no idea what it does? Or are you familiar with how both Cross Apply and Outer Apply work but don’t know how they can work in the real world?
Learn all about Cross Apply and Outer Apply in this guide, including:
- What Cross Apply is
- What Outer Apply is
- How they differ from Inner and Outer Joins
- Which databases support this feature
- Why you would use it
- Some realistic examples
Let’s get into the guide.
How to Show a List of Databases in SQL
If you want to see a list of databases on your server, you can run commands to do this. Let’s see how you can do this in several different SQL vendors.
SQL Drop Database Command
Sometimes you’ll need to delete a database or drop a database in SQL. There’s a command to do this in SQL. Let’s see how you can do this in different databases.
JSON in PostgreSQL: The Ultimate Guide
PostgreSQL has quite a lot of features for storing and working with JSON data.
In this guide, you’ll learn:
- What JSON is and why you might want to use it
- Creating a table to store JSON data
- How to add, read, update, and delete JSON data
- Tips for performance, validating and working with JSON
Let’s get into the guide.
SQL Show Tables: List All Tables in a Database
Do you need to get a list of all the tables in your SQL database?
Learn how to do this in several different database vendors in this guide.
How to Update from Select in SQL
The basic UPDATE statement in SQL allows us to update data in a table.
But what if we want to update data in one table based on data in another table?
There are a few ways to do that in different versions of SQL.
Let’s take a look at the SQL Update from Select techniques in this guide.
A Guide to DBMS_OUTPUT.PUT_LINE
In this guide, you’ll learn what the DBMS_OUTPUT.PUT_LINE function in Oracle does, see some examples, learn how to enable it in different editors, and learn why it should not be used in production code.
Let’s take a look.
A Guide to SQL Bind Variables
Many SQL queries that we write need to use values provided from other areas, such as user input or an application.
There are a couple of ways to include these values in your queries, but there is one preferred way.
The preferred way is to use bind variables.
In this guide, you’ll learn all about bind variables and how to use them in Oracle, SQL Server, MySQL, and PostgreSQL.
Let’s take a look.
JSON in Oracle: The Ultimate Guide
Oracle has quite a few features for storing and working with JSON data.
In this guide, you’ll learn:
- What JSON is and why you might want to use it
- Creating a table to store JSON data
- How to add, read, update, and delete JSON data
- Tips for performance, validating and working with JSON
Let’s get into the guide.
800 Free Data Sets
Do you want to practice your SQL, database, or data analysis skills?
If so, you’ll need some data, or a data set, to work on.
On this page, you can find a list of several hundred data sets you can use.