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 readingIn PostgreSQL, we can use the - operator to subtract one or more years from a date.
The following example returns all rows that contain at least one numerical digit in PostgreSQL.
Continue readingIn PostgreSQL, we can use the + operator to add one or more years to a date.
MySQL and MariaDB have a SHOW TABLES statement, which outputs a list of tables and views in a database. PostgreSQL doesn’t have a SHOW TABLES statement, but it does have a command that produces a similar result.
In Postgres, you can use the \dt command to show a list of tables. This is a psql command (psql is the interactive terminal for PostgreSQL).
In PostgreSQL, we can use the + operator to add one or more weeks to a date. We have a few options when it comes to specifying the actual number of weeks.
When using PostgreSQL’s INTERSECT operator, if you encounter an error that reads “ERROR: each INTERSECT 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 INTERSECT operator.
The way to fix this is to ensure that both SELECT statements return the same number of columns.
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.
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.
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.