Some DBMSs such as Oracle, MySQL, and MariaDB have a DESCRIBE command that returns information about tables and views. It goes DESCRIBE table where table is the name of the table or view, and it can also be followed by a column name if you only want information about a specific column.
PostgreSQL doesn’t have a DESCRIBE TABLE command as such, but there are alternatives.
In SQLite, we can use the IF EXISTS clause of the DROP TABLE statement to check whether the table exists or not before dropping it.
In SQLite, the table_list pragma returns information about the tables and views in the schema.
It was first introduced in SQLite version 3.37.0 (released on 2021-11-27).
Continue readingIn MariaDB, we can use the IF EXISTS clause of the DROP TABLE statement to check whether the table exists or not before dropping it.
The very useful DROP TABLE IF EXISTS syntax was finally introduced in Oracle Database – Oracle Database 23c to be precise. This syntax allows us to run a DROP TABLE statement without getting an error if the table doesn’t exist.
Earlier versions of Oracle don’t support the IF EXISTS clause. Therefore, if we want to avoid any nasty errors resulting from trying to drop a non-existent table, we need to do a bit of extra work.
Below are three options for dropping a table if it exists in Oracle.
Continue readingIn MySQL, we can use the IF EXISTS clause of the DROP TABLE statement to check whether the table exists or not before dropping it.
In SQLite, we can query the sqlite_schema table to find out whether a given table exists.
Prior to SQLite version 3.33.0, this table was referred to as sqlite_master (it can still be referred to as such in subsequent releases for backwards compatibility).
Here are four ways to check whether or not a table exists in a MariaDB database.
Continue readingBelow are five ways to check if a table exists in a PostgreSQL database.
Continue readingIn MariaDB, you can use the IF NOT EXISTS clause of the CREATE TABLE statement to check whether or not a table of the same name already exists in the database before creating it.
The table will only be created if there isn’t already one with the same name.
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