PostgreSQL offers a handy feature called domains that can greatly enhance data integrity and simplify database design. In this article, we’ll explore what domains are, how they work, and when to use them in our database projects.
Continue readingHow to Update an Array in PostgreSQL
PostgreSQL allows us to create arrays and store them in the database as an array type. We can then go back later and update those arrays as required.
We can either replace the whole array, append or prepend elements, or update individual elements within the array. When we update individual elements, we can update one element or a whole slice. Below are examples of updating an array in PostgreSQL.
Continue readingWhen LPAD() or RPAD() Don’t Seem to Work in PostgreSQL
If you’re trying to use either lpad() or rpad() to pad a string in PostgreSQL but it’s just not working, maybe it’s because of the reasons listed below.
Fortunately this issue has a simple fix, and it can be resolved within seconds.
Continue readingA Quick Look at the MD5() Function in PostgreSQL
In PostgreSQL, the md5() function computes the MD5 hash of the specific text, and outputs the result in hexadecimal.
We pass the text as an argument when calling the function.
Continue readingSQL for Beginners: 10 Must-Know Concepts to Kickstart Your Database Journey
SQL stands for Structured Query Language. It’s the go-to query language for most of us who develop relational databases. If you want to work with relational database management systems, learning SQL is pretty much non-negotiable. Especially if you want to become a SQL developer.
If you’re interested in becoming a SQL developer, here are ten essential SQL concepts that you need to learn.
Continue readingHow to DROP Tables with Foreign Key Relationships in PostgreSQL
Nothing pulls me out of the “zone” quicker than attempting to drop a table, only to be told “Nope, that table has a dependency!”.
Granted, this usually only happens in my development environments, as I rarely have any need to drop tables in a production environment.
And that’s probably why it “pulls me out of the zone”. I suddenly have to stop and start thinking about what tables contain foreign keys to the one I’m trying to drop. In dev environments, we’re often trying things out and so it’s not out of the question that we might inadvertently try to drop a table without realising it has dependent objects.
Fortunately, when we’re working with PostgreSQL, we have a quick and easy method to overcome this barrier.
Continue reading2 Functions that Return the Position of a Substring within a String in PostgreSQL
PostgreSQL sometimes provides us with multiple functions that basically do the same thing. Such is the case with the following two functions that return the position of a given substring within a string.
Continue readingA Quick Look at TO_HEX() in PostgreSQL
In PostgreSQL, we can use the to_hex() function to convert a number to its equivalent hexadecimal representation.
The function accepts the number as an integer or bigint, and it returns the result as a text representation of its hexadecimal equivalent.
Continue readingIntroduction to the Enum Data Type in SQL
The Enum (enumeration) data type in SQL is a specialised string object that allows us to define a list of predefined values for a column. This data type can be particularly useful when we want to restrict the possible values that can be stored in a specific column to a fixed set of options.
How to TRUNCATE a Temporal Table in SQL Server
Temporal tables in SQL Server provide a powerful way to track historical data changes. However, when it comes to clearing out data from these tables, the standard TRUNCATE statement doesn’t work the same as it does on normal (non-temporal) tables.
This article will guide you through the process of truncating a temporal table while maintaining its integrity.
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