Data Definition Language (DDL) is a type of SQL command that is used to define, modify, and manage the structure of database objects such as tables, indexes, schemas, and views.
Thank you for reading this post, don't forget to subscribe!- It primarily focuses on the creation, alteration, and deletion of database schema and its components.
Key Operations of DDL:
- CREATE: Used to create new database or objects in a database.
- ALTER: Used to modify the structure of a database, such as adding or dropping columns in a table.
- DROP: Deletes a database object from the database permanently.
- TRUNCATE: Deletes data from table.
- RENAME: Used to rename a table or a column.
- COMMENT: Used to comment on the data dictionary.
Oracle Data Types:
In Oracle, data types are used to define the type of data that can be stored in a column. Oracle provides a wide range of data types, allowing users to store various kinds of data such as numbers, strings, dates, and more.
Here’s a breakdown of the most commonly used Oracle data types:
- Numeric data types: NUMBER, INTEGER, FLOAT, BINARY_FLOAT, BINARY_DOUBLE.
- Character data types: CHAR, VARCHAR2, CLOB.
- Date and Time data types: DATE, TIMESTAMP, INTERVAL.
- Large object data types: BFILE, BLOB, CLOB, NCLOB.
- Rowid Data types: ROWID, UNROWID(SIZE)