The LOG() function in SQLite calculates the logarithm of a given number to a specified base, with 10 being the default base.
This is helpful for logarithmic transformations or calculations requiring a specific base (e.g., base 10 for common logarithms or base 2 for binary logarithms).
Continue readingIn SQLite, the ceil() and ceiling() functions are used to return the smallest integer that is greater than or equal to a given number. They both serve the same purpose, and either function can be used interchangeably.
The RADIANS() function in SQLite is a mathematical function that converts an angle from degrees to radians. This can be handy when working with trigonometric calculations in your database queries, as some mathematical functions (such as SIN(), TAN()) expect angles in radians rather than degrees.
The SERIAL data type in PostgreSQL is a pseudo-type used to create an auto-incrementing sequence of integers for a column. It is commonly used for primary keys, as it eliminates the need to manually assign unique identifiers for each new record. PostgreSQL handles this by automatically creating a sequence object that supplies a unique number each time a new row is inserted.
PostgreSQL provides three SERIAL types, each with two options for usage; which effectively equates to six different types. So basically, we have six options to choose from when creating a SERIAL column.
The ASIN() function in SQLite calculates the arc sine (inverse sine) of a given numeric value. The result is the angle in radians whose sine is the specified number.
The ACOS() function in SQLite is used to calculate the arc cosine (inverse cosine) of a given numeric value. The result is the angle in radians whose cosine is the specified number.
In relational database management systems (RDBMSs), constraints are nifty tools that we can use to ensure the integrity, accuracy, and reliability of the data stored in our database.
Constraints can enforce rules at the column and table levels, guiding how data can be inserted, updated, or deleted. Whether you’re defining the uniqueness of a value, establishing relationships between tables, or ensuring that critical fields are never left blank, constraints play an important role in the design of relational databases.
Continue readingIf you work with MySQL databases, you may have encountered the SERIAL type in a table’s definition. And if you’ve come over from PostgreSQL, you might have a false expectation about how MySQL’s SERIAL works – unless you already know 😉
Below is a quick overview of MySQL’s SERIAL type, including an explanation of how it differs from PostgreSQL’s SERIAL type and similar functionality from other DBMSs.
Probably the most widely known key type in SQL is the primary key, which is chosen to uniquely identify each row in a table. Perhaps next is the foreign key, which is used to establish a relationship between tables.
But there are more key types than this, and the differences between them can be subtle, but important. Here we’ll look at nine of the various key types in SQL.
Continue readingProbably the most common way to join tables in SQL is with the ON clause. But that’s not the only way.
We can also join with the USING clause, which can be more concise, while providing the same or similar results. And there’s also the concept of a natural join, which is more concise again.
Let’s take a look at these three join options and compare them side by side.
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