General SQL related
What are the key commands within the TCL category?
COMMIT ROLLBACK SAVEPOINT
What are the commands within the DDL category?
CREATE DROP ALTER TRUNCATE -Affects the overall database/table schema instead of the actual data.
What is DML used for?
Control how you want users to access the data. Define privileges for accessing the data/table.
What are the different types of SQL statements?
DDL - Data Definition Language DML - Data Manipulation Language DCL - Data Control Language TCL - Transaction Control Language DRL - Data Retrieval Language
What is DDL and what does it do?
Data Definition Language Used to define/modify the database objects - table, views.... Auto committed
What is DML used for?
Data Manipulation Language
What are the commands within DCL category?
GRANT REVOKE -Affects accessibility to the database/table.
What are the commands within the DML category?
INSERT UPDATE DELETE MERGE -Affects the data/rows instead of the table or the schema definitions or table.
What is the main command within DRL?
SELECT
What does SQL stand for?
Structured Query Language Means to communicate with a relational database. The instructions given to a database in a structured/defined format and this is SQL.
What is DRL used for?
This defines how the data is retrieved/SELECTED.
What is TCL used for?
This defines how you want the transaction to be controlled. Once connected to the database, and you run commands like insert/delete, the TCL command is used to define how the transaction is controlled. If there is an error - roll back?
