Running total refers to the sum of values in all cells of a column that precedes the next cell in that particular column.
Introduction: PostgreSQL, also known as Postgres, is a feature-rich and highly acclaimed open-source relational database management system (RDBMS). In this comprehensive guide, we will delve into the world of PostgreSQL commands, equipping you with the knowledge needed to effectively manage and interact with your PostgreSQL databases.
createdb, dropdb, and psql commandsCREATE TABLE, ALTER TABLE, and DROP TABLE commandsINSERT INTO, UPDATE, and DELETE FROM commandsSELECT, WHERE, ORDER BY, GROUP BY, and JOIN commandsCREATE INDEX and DROP INDEX commandsBEGIN, COMMIT, and ROLLBACK commandsCREATE USER, ALTER USER, GRANT, and REVOKE commandspg_dump and pg_restore commandsConclusion: PostgreSQL, the versatile and powerful RDBMS, offers an extensive suite of commands to manage and interact with your databases efficiently. This comprehensive guide has provided a detailed overview of essential PostgreSQL commands, including database creation, table management, data manipulation, querying, indexing, transaction handling, user and permission management, and backup and restore operations.
By familiarizing yourself with these PostgreSQL commands and leveraging their capabilities, you can unlock the full potential of Postgres and streamline your database management processes. Remember to consult the official PostgreSQL documentation and other valuable resources to further expand your knowledge and proficiency in using PostgreSQL effectively.
Empower yourself with the knowledge of PostgreSQL commands, and embark on a journey to harness the power and versatility of Postgres for your data management needs.
postgres=>\connect databasenamepostgres=> \c databasenamepostgres=> \c mydatabase or postgres=> \connect mydatabase
mydatabase=>
SQL> SELECT NAME FROM v$database
SQL> shutdown immediate; Database closed. Database dismounted. ORACLE instance shut down.
SQL> startup;
ORACLE instance started. Total System Global Area 4966053832 bytes Fixed Size 8906696 bytes Variable Size 922746880 bytes Database Buffers 4026531840 bytes Redo Buffers 7868416 bytes Database mounted
Open the database
SQL> alter database open;
SQL> select instance_name, status from v$instance;
INSTANCE_NAME STATUS
---------------- ------------
orcl MOUNTED
SQL> alter database open;
Database altered.
SQL> select instance_name, status from v$instance;INSTANCE_NAME STATUS
---------------- ------------
orcl OPEN
SELECT id FROM (SELECT id, ROW_NUMBER() OVER(PARTITION BY name ORDER BY name) AS row_num FROM demo) d WHERE row_num > 1; +------+ | id | +------+ | 7 | | 3 | +------+ 2 rows in set (0.000 sec)
DELETE FROM demo WHERE id IN (SELECT id FROM (SELECT id,ROW_NUMBER() OVER (PARTITION BY name ORDER BY name) AS row_num FROM demo) d WHERE row_num > 1);
Query OK, 2 rows affected (0.005 sec)
SELECT id FROM (SELECT id, ROW_NUMBER() OVER(PARTITION BY name ORDER BY name) AS row_num FROM demo) d WHERE row_num > 1;
Empty set (0.000 sec)
Done, duplicate data deleted.
bash#$ sqlplus / as sysdba
SQL> shutdown immediate;
SQL> startup mount exclusive restrict;
SQL> drop database;
CREATE DATABASE myFirstDB;
Check if the database already exists and createCREATE DATABASE IF NOT EXISTS myFirstDB;
To list all the databases in a server.
SHOW DATABASES;
To connect to your databaseUSE DATABASE_NAME;
Once you have selected your database, use following to create userCREATE USER 'username'@'localhost' IDENTIFIED BY 'user_password';
To create a user that can connect from any host, use the '%' wildcard as a host part:CREATE USER 'username'@'%' IDENTIFIED BY 'user_password';
No you can login to your MariaDB using the new user and password
mysql -h localhost -P port -u username -p user_password
Running total refers to the sum of values in all cells of a column that precedes the next cell in that particular column. Using Window Funct...