Postgres and Open Source Experts

In PostgreSQL, the ALTER TABLE command updates the table’s structure, such as adding a new column, renaming a column, changing data type, etc.

Postgres, the “CREATE OR REPLACE VIEW” command is used to modify the view’s definition. The ALTER VIEW command allows us to alter the view’s auxiliary properties.

In PostgreSQL, the “CREATE USER” command is used to create a new user. To create a user with the password, execute this command with the “PASSWORD” attribute.

In PostgreSQL, creating a table from a CSV file means importing a CSV file into the Postgres table. For this, execute the COPY command to create a Postgres table via the CSV file.

PostgreSQL provides a built-in function named ARRAY_CAT() and a concatenation operator “||” that assists us in concatenating multiple arrays into a single array.

Execute the “ALTER USER” or “ALTER ROLE” command, followed by the default user name and the PASSWORD attribute to set the default user password in PostgreSQL.

In PostgreSQL, the DATE_TRUNC() function is a convenient way for truncating/rounding the timestamps to the desired level of precision.

Sometimes a “Permission Denied” error occurs while importing a CSV file into a Postgres table. To fix this error, you need to change the file reading permissions.

In Postgres, the DEFAULT keyword is used with the help of CREATE TABLE or ALTER TABLE statement to set a default value to a column.

To extract a year from a date, the built-in EXTRACT() and DATE_PART() functions are used in Postgres. To do so, pass the “YEAR" and the timestamp as arguments to any of these functions.