If you’re getting “Error: in prepare, SELECTs to the left and right of UNION do not have the same number of result columns…” in when trying to use the UNION operator in SQLite, it’s because one of the SELECT statements is returning more columns than the other.
Author: Ian
Calculate the Number of Seconds Since a Particular Date/Time in SQLite
If you need to calculate the number of seconds that have passed since a given date and time, you can use the UNIXEPOCH() function.
Note that this function was introduced in SQLite 3.38.0, so it will only work if you’re using SQLite 3.38.0 or later.
Continue readingINITCAP() – Convert to Initial Caps in PostgreSQL
In PostgreSQL, we can use the initcap() function to format a string of text to use initial capitals. That is, it converts the first letter of each word to upper case and the rest to lower case.
2 Ways to Show All Databases in PostgreSQL (psql)
Here are a couple of ways to show a list of databases when using psql with PostgreSQL.
The first option can be used when we’re already connected to PostgreSQL. The second option can be used when we don’t currently have a connection to Postgres.
Continue readingAdd Days to a Date in SQLite
In SQLite, we can use the DATE() function to add a given number of days to a date.
If we’re dealing with datetime values, we can use the DATETIME() function.
nullvalue: Show NULL Values in SQLite
When using the SQLite command line interface (CLI), by default, whenever a query returns a null value, the output is the empty string ('').
We can change this by using the -nullvalue command line option when launching SQLite.
We can also use the .nullvalue dot command if we’re already in the SQLite CLI.
How to Convert to Uppercase in MariaDB
In MariaDB, we can use the UPPER() function to convert lowercase characters to their uppercase equivalent.
We can alternatively use UCASE(), which is a synonym of UPPER().
JSON Functions & Operators in SQLite (Full List)
Below is a full list of JSON functions and JSON operators available in SQLite.
Continue readingHow to Detect if a Value Contains at Least One Numerical Digit in MariaDB
When working with MariaDB, you may occasionally find yourself needing to return all rows that contain at least one numerical digit.
In such cases, you may find the following example useful.
Continue readingHow to Convert to Uppercase in SQLite
In SQLite we can use the upper() function to convert lowercase characters to uppercase.