Computer ScienceCode 9618
Data Definition Language (DDL) and Data Manipulation Language (DML)
What this topic asks you to be able to do
- Demonstrate an understanding that the DBMS performs every act of building or altering the database's structure by means of its Data Definition Language (DDL)
- Demonstrate an understanding that the DBMS performs all querying and data maintenance through its DML
- Demonstrate an understanding that Structured Query Language (SQL) is the widely adopted standard for both DDL and DML across the industry
- Understand an SQL statement that has been supplied
- Understand supplied SQL (DDL) statements and be capable of writing straightforward SQL (DDL) statements drawing on a sub-set of the statements
- Create a database by writing CREATE DATABASE
- Create a table definition with CREATE TABLE, including setting up attributes that have suitable data types, chosen from: CHARACTER, VARCHAR(n), BOOLEAN, INTEGER, REAL, DATE, TIME
- Modify the structure of an existing table by using ALTER TABLE
- Set up a primary key on a table using PRIMARY KEY (field)
- add a foreign key onto one table, written as FOREIGN KEY (field) REFERENCES Table (Field)
- Write an SQL script (DML) that queries or changes data held in no more than two database tables
- Query constructs, including SELECT... FROM, WHERE, ORDER BY, GROUP BY, INNER JOIN, SUM, COUNT, AVG
- Data maintenance, including the INSERT INTO, DELETE FROM, UPDATE statements