Next: Basic Structure
SQL has become the standard relational database language.
It has several parts:
We will only look at basic DDL, the DML and views.
Integrity features will be covered in Chapter 5.
- Data definition language (DDL) - provides commands to
- Define relation schemes.
- Delete relations.
- Create indices.
- Modify schemes.
- Interactive data manipulation language (DML) - a query language
based on both relational algebra and tuple relational calculus, plus
commands to insert, delete and modify tuples.
- Embedded data manipulation language - for use within programming
languages like C, PL/1, Cobol, Pascal, etc.
- View Definition - commands for defining views
- Authorization - specifying access rights to relations and views.
- Integrity - a limited form of integrity checking.
- Transaction control - specifying beginning and end of transactions.
Fri May 22 19:39:12 PDT 1998