Below are examples of using SQL to return the last day of the month across various DBMSs.
This could be the last day of the current month, or the last day of a month based on a given date.
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Install Redis on a Mac with Homebrew
Below are the steps that I used to install Redis on my M1 Mac. The M1 Mac (and M2) uses the ARM64 architecture, but this is not a problem, as Redis versions 4.0 and above support the ARM architecture.
Continue readingHow to Convert to Lowercase in SQLite
In SQLite we can use the lower() function to convert uppercase characters to lowercase.
Find Duplicate Rows that have a Primary Key in SQL
Here are examples of using SQL to return duplicate rows when those rows have a primary key or other unique identifier column.
These queries work in most of the major RDBMSs, including SQL Server, Oracle, MySQL, MariaDB, PostgreSQL, and SQLite.
Continue readingHow to Get the Definition of a Generated Column in PostgreSQL
If you have a generated column in PostgreSQL, you can use the following methods to find the definition of that column.
Continue readingAdd Years to a Date in SQLite
In SQLite, we can use the DATE() function to add one or more years to a date.
For datetime values, we can use the DATETIME() function.
Find Rows that Contain Lowercase Characters in SQL
Most RDBMSs provide at least a few ways to return rows that contain lowercase characters. Here are some options available in the major RDBMSs.
Continue readingHow to Create a Generated Column in PostgreSQL
In PostgreSQL, a generated column is a special column that is always computed from other columns. A generated column doesn’t have a fixed value like in a base column. Rather, its value is determined by an expression that references other columns in the table.
Generated columns are included in the SQL standard (ISO/IEC 9075), and are supported by most major RDBMSs. Generated columns were first introduced in PostgreSQL 12.
Continue readingSelect Duplicate Rows in SQL
Here’s an example of using SQL to find duplicate rows in a database table. This technique can be used in most of the major RDBMSs, including SQL Server, Oracle, MySQL, MariaDB, PostgreSQL, and SQLite.
Continue reading2 Ways to Get the Definition of a Generated Column in MySQL
A generated column is one whose value is derived from an expression, as opposed to a fixed value. The expression typically uses other columns in the same table to compute the derived value.
We can create a generated column in MySQL very easily. But what if we want to go back later and see its definition?
Here are two options for returning the definition of a generated column in MySQL.
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