An SQL database, or Structured Query Language database, is a type of database that uses SQL as its primary interface for accessing and managing the data. Here are some key aspects of an SQL database:
1. **Structured Data Storage**: SQL databases store data in structured formats, typically using tables that consist of rows and columns. Each table represents a specific entity, and each column represents an attribute of that entity.
2. **SQL Language**: SQL is a standardized programming language specifically designed for managing and manipulating relational databases. It includes commands for querying data, updating data, inserting data, and deleting data. Common SQL commands include SELECT, INSERT, UPDATE, DELETE, and CREATE TABLE.
3. **Relational Model**: SQL databases are based on the relational model, which organizes data into tables (relations) that can be linked (related) based on data common to each. This model provides a powerful way to manage data and perform complex queries.
4. **ACID Properties**: SQL databases often support ACID (Atomicity, Consistency, Isolation, Durability) properties, which ensure reliable processing of database transactions. These properties are critical for maintaining data integrity, especially in applications where transactions are frequent.
5. **Database Management Systems (DBMS)**: An SQL database is managed by a Database Management System (DBMS), such as MySQL, PostgreSQL, Microsoft SQL Server, or Oracle Database. The DBMS provides tools for defining, creating, querying, updating, and administering the database.
6. **Data Integrity and Security**: SQL databases include features for maintaining data integrity (such as primary keys, foreign keys, and unique constraints) and security (such as user authentication and authorization).
7. **Scalability and Performance**: SQL databases are designed to handle a wide range of workloads, from small applications to large enterprise systems, with optimizations for performance and scalability.
Overall, SQL databases are a powerful and flexible tool for managing structured data, widely used in various applications from small business solutions to large-scale enterprise systems.
Syllabus
Structured Query Language
01 – Database Basics and Structured Query Language
- Introduction to SQL
In our first , we’ll explore the basic structure and history of relational databases. You’ll learn the history of SQL, then we’ll review some key terms. Then, you’ll discover what SQL is and how it’s used with a relational database.
02 – Filtering and Retrieving Data
- Retrieving Data, Updating Data, Inserting Data, Deleting Data
In this , you’ll learn how to use SQL to filter and retrieve data from tables. We’ll talk about important query terms that allow you to communicate with your database, as well as syntax rules that will help you to create clear and understandable queries while avoiding system generated errors.
03-Sorting and Filtering Data
- Sorting and Filtering Data, Advanced Filtering,
In this , you’ll learn how to use SQL to filter retrieved data. You’ll practice sorting retrieved data using the ORDER BY clause. You’ll be able to sort single and multiple columns, and you’ll know how to specify sort directions such as ascending and descending order. You’ll also learn additional query terms that will help you customize your SQL queries.
04 – Calculated Fields and Functions
In this, you’ll learn how to reformat retrieved data with calculated fields and functions. You’ll also learn how to create alternate names for columns, and you’ll discover the secret behind merging columns with the concatenation symbol.
05 – Summarizing and Grouping Data
- Summarizing Data, Grouping Data
In this , we’ll discuss gathering significant statistics from data using aggregate functions. You’ll also learn how to use the GROUP BY clause in conjunction with an aggregate function to gather important statistics from a table. Then you’ll find out how to use the HAVING clause in conjunction with an aggregate function to filter groups of data from a table.
06 – Working with Sub queries
- Using Subqueries
Its all about sub queries. You’ll learn how to extract data from multiple tables simultaneously, how to use calculated fields in sub queries, how to use the DATEPART () function in sub queries, and how to use aggregate functions in sub queries. Then we’ll talk about qualification—a technique used to combine a table name with a column name so there’s no question about which table the column name refers to.
07 – Creating and Using Table Joins
- Joining Tables, Managing Tables, Using Views
In this , you’ll learn how to use joins to gather information from two or more tables simultaneously. You’ll learn how to use the inner join, self-join, natural join, and the outer join. Then you’ll become familiar with the term Cartesian product.
08 – Inserting, Updating, and Deleting Data
- Stored Procedures, Using Cursors
In today’s , you’ll discover how to manipulate data using the INSERT, UPDATE, and DELETE statements. You’ll learn how to insert partial and complete rows into a table, and how to update information already stored in a table. You find out how to transfer data to a new table, how to transfer data to an existing table, and how to delete rows from a table.
09 – Table Creation and Maintenance
- Using Cursors, Using Transactions
Today you’ll find out how you can use SQL to create and maintain tables. You’ll learn how to use the CREATE TABLE keywords to create a table, then we’ll discuss how to use the ALTER TABLE, DROP TABLE, ADD COLUMN, and DROP COLUMN keywords to manipulate the tables themselves. You’ll also find out how to define a primary key, data type, and field size.
10 – Creating and Understanding Views
In this , you’ll learn how and why views are used in SQL. You’ll learn how to create and use views to simplify complex queries, summarize data, and manipulate data stored in tables. I’ll also teach you how to update and delete a view.
11 – Understanding Transaction Processing, Constraints, and Indexes
Today, you’ll learn how transaction processing, constraints, and indexes are implemented in SQL. You’ll work through an example that demonstrates how a transaction is created, how constraints are used in the creation of a table, and how indexes are used to improve the performance of a database by optimizing the speed at which queries are processed.
12 – Understanding Stored Procedures, Triggers, and Cursors
In our final , you’ll find out how stored procedures, triggers, and cursors are implemented in SQL. You’ll see how stored procedures are created and executed, as well as how triggers work. You’ll also see how cursors are declared in SQL.
13 – How to do database testing.
- Data Mapping
- ACID properties validation
Data integrity:
- Business rule conformity
1) Transactions:
2) Database schema:
3) Trigger:
4) Stored Procedures:
- Field constraints – Default value, unique value and foreign key:
How To Test Database:
- Create your own Queries
- Observe data table by table
- Get query from developer
