Introduction to SQL

   INTRODUCTION TO SQL: Module 3 Data Definition Language: Database structure is defined and maintained using Data Definition Language (DDL), a subset of SQL (Structured Query Language). Using DDL, database objects such as tables, indexes, and constraints can be created, changed, and destroyed. You can create and modify tables, indexes, and other database objects using the DDL statements' CREATE, ALTER, and DROP commands. These statements outline the structure of a database, describing data types, relationships, and constraints to protect data integrity. Among the DDL statements are the following: The database's CREATE TABLE statement is used to create new tables. The table's columns are described together with their data types and any column limitations. Changes to a table's structure can be made using the ALTER TABLE statement. It can be used to change data types, add or remove columns from tables, and create limitations. Use the statement "DROP TABLE" to el