Structured query language This is a presentation by JOSEPH ESTRada on the beauty of Structured Query Language

So, what is SQL you ask? Language designed for the retrieval and management of data. Standard Data Manipulation Language(DML). Data definition language(DDL). Defines structure of the database.

Literal values (Strings, numbers, hexadecimal values, boolean values, bit-field values, null values) database, table, index, column, and alias names reserved words user-defined variables comments MYSql language structure

literal values string: character sequence in single or double quotes. optional “collate” clause used to specify collation. numbers: sequence of digits. hexadecimal values: Act as binary strings or 64-bit precision integers. Boolean values: booleans. bit-field values null values

mysql language structure cont... Identifiers: DB, table, index, column, and alias names. reserved words: SELECT, UPDATE, DELETE, etc... (pg 570) user-defined variables: allows shared data between statements. comments: #, --, /* */

Data Definition statements ALTER DATABASE: change characteristics of db. ALTER TABLE: change table structure/schema. CREATE DATABASE: creates new db. CREATE TABLE: creates new table. DROP DATABASE: removes a dB. DROP TABLE: removes a table. RENAME TABLE: changes table name.

Data manipulation statements (not complete) DELETe: deletes tuples insert: Insert tuples into a given table select: Relational projection operator update: Updates attribute/s

Aggregate functions avg(column): AVg of a column COUnt(column): number of rows w/o null value MAX(column): highest value of a column. MIN(column): Lowest value of a column. SUM(column): Total sum of a column.

Create TABLE (DDL)

INSERT INTO Course (DML)

group by Number of classes taught per instructor with GROUP by clause.

predicate Classes under CS department with units 3 or greater.

count Amount of courses taught by each department.

delete (DML) delete all tuples.

DROP TABLE (DDL) delete the table from the db.

EXIT(0)