Oracle Database is a comprehensive and robust relational database management system (RDBMS) widely used for enterprise-level applications. This cheat sheet presents essential commands and queries to interact efficiently with Oracle databases.

Connecting to Oracle:

CommandDescription
sqlplus [username]/[password]@[hostname]:[port]/[service_name]Connect to Oracle using SQL*Plus.
CONNECT [username]/[password]@[hostname]:[port]/[service_name]Alternative command to connect.
SHOW USER;Display the current Oracle user.

Managing Tables:

CommandDescription
CREATE TABLE [table_name] ([column_definitions]);Create a new table with specified columns.
DESC [table_name];Display the structure of a table.
SELECT table_name FROM user_tables;List all tables in the current user’s schema.

Inserting Data:

CommandDescription
INSERT INTO [table_name] VALUES (value1, value2, ...);Insert data into a table.
INSERT INTO [table_name] (column1, column2, ...) VALUES (value1, value2, ...);Insert data with specified columns.

Querying Data:

CommandDescription
SELECT * FROM [table_name];Retrieve all columns from a table.
SELECT column1, column2 FROM [table_name] WHERE condition;Retrieve specific columns with conditions.
UPDATE [table_name] SET column1 = value1 WHERE condition;Update data in a table.
DELETE FROM [table_name] WHERE condition;Delete data from a table.

Filtering and Sorting:

CommandDescription
SELECT * FROM [table_name] WHERE condition ORDER BY column_name ASC/DESC;Filter and sort query results.
FETCH FIRST [number] ROWS ONLY;Limit the number of rows returned.

Aggregation Functions:

CommandDescription
SELECT COUNT(column_name) FROM [table_name];Count the number of rows in a table.
SELECT AVG(column_name) FROM [table_name];Calculate the average value of a column.
SELECT MAX(column_name) FROM [table_name];Retrieve the maximum value in a column.
SELECT MIN(column_name) FROM [table_name];Retrieve the minimum value in a column.
SELECT SUM(column_name) FROM [table_name];Calculate the sum of values in a column.

Conclusion

This Oracle Database cheat sheet serves as a valuable resource for Oracle users, providing essential commands for database management, table creation, data manipulation, and querying. Oracle’s feature-rich capabilities make it a preferred choice for enterprise-level applications. Adapt these commands to your specific Oracle environment and database requirements.