psql:tldr:f813c

The command "psql -c '${query}' ${database}" is a command-line command used to execute a SQL query in PostgreSQL.

Here is a breakdown of the command:

• "psql" is the command to enter the PostgreSQL command-line interface.
• "-c" is an option that allows you to specify the SQL command directly in the command-line.
• "${query}" is a placeholder for the SQL query. You need to replace this placeholder with the actual SQL query you want to execute.
• "${database}" is another placeholder that needs to be replaced with the name of the PostgreSQL database you want to connect to.

To use the command, you need to replace "${query}" with your actual SQL query and "${database}" with the name of your target database.

For example, if you want to execute the SQL query "SELECT * FROM employees;" in a database called "sampledb," the command would look like this:

psql -c 'SELECT * FROM employees;' sampledb

This would open the PostgreSQL command-line interface and execute the given SQL query in the specified database.