SQL database from scratch

Introduction to SQL for Web Developmentnotes:

 SQL Constraints
 Primary Keys and Constraints
 Check Constraints
 Foreign Keys for Data Integrity
 Default Values
 Commands in Data Definition Language
 Creating Tables
 Creating and Dropping Databases
 SQL Commands for Data Manipulation
 Selecting Students Based on Roll Numbers
 Updating and Deleting Data from Tables
 Data Insertion and Data Retrieval
 SQL Queries
 Selecting Data
 Using the SELECT Statement in SQL

 Applying Conditions in SQL Queries
 Reversing Conditions with
the NOT Operator

 Understanding SQL Queries
 Using SQL Operators to Compare Values
 Implementing the IN Operator for List
Values
 Subquery Results and Implications
 Writing SQL Queries Step by Step
 Storing Query Results for Future Reference

,  Finding Maximum Marks of Students in
Delhi
 Left Join and Right Join
 Left Join: Bringing complete data from the
left table with overlapping values
 Right Join: Bringing complete data from the
right table with overlapping values
 Inner Join
 Combining data with overlapping values
between two tables
 Numeric Data Types
 Logical Operators in SQL
 Working with Logical Operators in SQL
 Using Logic of Modules Operator in Basic
Math
 Between Operator for Range Selection
 ER Diagrams
 Visualizing Relationships between Tables
with ER Diagrams
 Database Creation and Table Management
 Database Schemas and Table Designs
 Table Structures in Databases
 Creating and Managing Databases in SQL
 SQL Query Operations
 SQL Commands and Syntax
 Ordering Data with the ORDER BY Clause

 Case Sensitivity in SQL Programming
 Data Modeling and Design Concepts
 Data Types in SQL

,  Cascading Effects in Foreign Key Relationships
 Data Manipulation and Transaction Control
Language
 SQL Operators to Compare Values
 Primary and Foreign Keys
 Using Foreign Keys for Data Integrity
 Understanding SQL Queries in English
 Data Types in SQL
 Data Manipulation and Transaction Control
Language

Basics of Database
Management Systems - SQL
Constraints
SQL Constraints

 Used to enforce rules on the data in a table
 Ensured data accuracy and consistency
 Examples: check constraints, default values,
primary keys
Default Values

 A default value is a value that is automatically
assigned to a column
 If no value is given during data insertion
Commands in Data Definition Language

 Create, alter, drop, truncate, and other
commands used for managing objects in a
database

,  Examples: CREATE TABLE, ALTER TABLE, DROP
TABLE
Check Constraints

 A check constraint is a type of constraint that
checks the values in a column
 Ensures the values meet certain conditions
Left Join: Bringing complete data from the
left table with overlapping values

 A left join returns all the rows from the left table
and matching rows from the right table
 If there are no matches, the result set contains
null values
Primary Keys and Constraints

 A primary key is a column or set of columns that
uniquely identifies a row
 Enforced by a primary key constraint
Working with Logical Operators in SQL

 AND, OR, and NOT used in the WHERE clause to
combine conditions
Understanding Foreign Keys in Database
Design

 A foreign key is a column or set of columns that
refer to the primary key of another table
 Enforced by a foreign key constraint
Using Foreign Keys for Data Integrity