Summary SQL Programming Language NOTES

SQL
Created @December 18, 2023 8:48 PM

Status Open

Updated @February 7, 2024 3:31 PM




SQL 1

, SQL

INTRODUCTION

SQL —> Structured Query Language —> programming language designed to
manage data stored in relational databases used for…

web frameworks

database applications




MANIPULATION


Relational Databases —>
Syntax

-- relational database --> one table

SELECT * FROM celebs;


relational databases —> database that organizes information into one or more
tables

table —> collection of data organized into rows and columns. —> referred to as
relations

EX: celebs

column —> set of data values of a particular type

EX: id, name, age

row —> single record in a table

EX: id = 1, name = Justin Bieber, age = 22


SQL 2

, All data stored in a relational database is of a certain data type

DATA TYPES

INTEGER —> positive or negative whole number

TEXT —> text string

DATE —> date formatted as YYYY-MM-DD

REAL —> decimal value



Statements —>
statement —> text that the database recognizes as a valid command —> end in a
semicolon (;)

Syntax

CREATE TABLE table_name (
column_1 data_type,
column_2 data_type,
column_3 data_type
);




clause —> perform specific tasks in SQL —> referred to as commands

written in capital letters

EX: CREATE TABLE

table_name —> refers to the name of the table that the command is applied to

parameter —> list of columns, data types, or values that are passed to a clause as
an argument

separated with commas

EX: (column_1 data_type, column_2 data_type…) —> the parameter




SQL 3

, structure of SQL statements —> vary

number of lines does not matter

statement can be written all on one line, or split up across multiple lines



Create —>
CREATE statements allow us to create a new table in the database

enclosed by parentheses and ends with a semicolon

Syntax

CREATE TABLE celebs (
id INTEGER,
name TEXT,
age INTEGER
);

-- celebs --> name of the table
-- (id INTEGER, name TEXT, age INTEGER) --> list of parameters defining
-- each column, or attribute in the table and its data type

CREATE TABLE —> clause that creates a new table

id —> first column in the table that stores an INTEGER

name —> second column in the table that stores a TEXT
age —> third column in the table that stores an INTEGER



Insert —>
INSERT statement inserts a new row into a table

INSERT INTO

VALUES



SQL 4