In PostgreSQL, we can use the + operator to add one or more months to a date. There are several options when it comes to specifying the actual number of months.
PostgreSQL
Fix ‘ERROR: column “colname” does not exist’ in PostgreSQL when using UNION, EXCEPT, or INTERSECT
If you’re getting “ERROR: column “colname” does not exist’” in PostgreSQL when using an operator such as UNION, EXCEPT, or INTERSECT, it may be that you’re trying to reference an aliased column by its column name.
Fix “ERROR: each EXCEPT query must have the same number of columns” in PostgreSQL
When using PostgreSQL’s EXCEPT operator, if you encounter an error that reads “ERROR: each EXCEPT query must have the same number of columns“, it’s because there’s a mismatch in the number of columns returned by the queries on either side of the EXCEPT operator.
The way to fix this is to ensure that both SELECT statements return the same number of columns.
Add Days to a Date in PostgreSQL
The + operator allows us to add one or more days to a given date in PostgreSQL. We have a few options when it comes to specifying the actual number of days.
Subtract Days from a Date in PostgreSQL
We can subtract one or more days from a date in PostgreSQL with the - operator.
PostgreSQL DATEADD() Equivalent
Updated 20 April 2024 to include the date_add() function.
SQL Server has its DATEADD() function that adds an interval to a date value. MySQL’s DATE_ADD() and ADDDATE() for does the same thing, as does MariaDB’s DATE_ADD() and ADDDATE(). SQLite has a DATE() function that also provides the option of adding an interval to a given date.
Prior to version 16, PostgreSQL didn’t have a DATEADD() or equivalent function. But with PostgreSQL 16 came with the introduction of the date_add() function, which allows us to add an interval to a timestamp with time zone.
We can also add and subtract values from dates with date/time operators such as + and -.
PostgreSQL VALUES Command Explained
In PostgreSQL, the VALUES command returns a set of one or more rows as a table. It’s a table value constructor that can be used as part of a larger command, or as a standalone SQL statement.