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SQL Tutorial
Data Modeling and Architecture Terminology Guide
A Brief History of SQL and its Usefulness
What are Different Types of Databases?
Writing SQL in Coginiti
Beginner
SQL Select
SQL Limit
SQL Where
SQL Create Table & Insert Into
SQL Comparison Operators
SQL Logical Operators
SQL In
SQL Like
SQL Is Null
SQL Between
SQL And, Or
SQL Not
SQL Order by
Export Data
Create a Table
Drop a Table
Create a View
SQL Parameters
Drop a View
Rename a Table
SQL Delete
Add a Column
Drop a Column
SQL Update
SQL Insert
Rename a Column
Intermediate
SQL Aggregate Functions
SQL Count
SQL Sum
SQL Min/Max
SQL Average
SQL Group by
SQL Case
SQL Having
Pivoting Data
Transpose Data
SQL Join
SQL Distinct
SQL Joins on Multiple Keys
SQL Union
Data Types
Precision and Scale
Subqueries
SQL Date Formats
Snowflake Advanced Date Formatting
Redshift TO_CHAR for Dates
BigQuery Date Formatting Functions
SQL Window Functions
Charting
String Functions in SQL
A Quick Guide to Pivoting Data
Advanced
Databricks SQL Functions
Trino Advanced SQL
CoginitiScript Macros
Churn Rate
Index in SQL
Query Date and Time
Group by Time
Round Timestamps
Get the First Row per Group
CoginitiScript Constants
Analysis
Coalesce in SQL
Calculating Percentiles
How to Do Type Casting
Import a CSV
Compare Values When One Is Null
How to Query a JSON Column
How to Write a Case Statement
How to Have Multiple Counts
Using a Common Table Expression (CTE)
Calculate Cumulative Sum (Running Total)

A Brief History of SQL and its Usefulness

SQL (Structured Query Language) is a programming language for storing, managing, manipulating, and processing data in relational databases. SQL has been around since the 1970s, and was standardized by the American National Standards Institute (ANSI) in 1986. Since then, SQL has become the most widely used language for managing relational databases and has undergone several revisions to keep pace with the evolving needs of the database industry.

SQL is pronounced “sequel” or sometimes “ess-cue-ell.”

What is SQL used for?

SQL is an essential part of the technology stack for many organizations and is widely used in business, government, and scientific applications across many roles including: Data Analysts, Business Intelligence Analysts, Data Scientists, Database Developers, and Data Engineers. SQL is used by organizations to interact with databases which store and manage data in a structured and efficient way.

The following are common tasks that people use SQL for:

  • Creating, modifying, and deleting database tables and records
  • Inserting, updating, and deleting data in a database
  • Retrieving data from a database with SELECT statements
  • Grouping and aggregating data
  • Joining data from multiple tables
  • Creating views and stored procedures
  • Performing data analysis and data mining
  • Managing the security and permissions of a database
  • Monitoring and optimizing database performance
  • Backing up and restoring databases
Statements, Functions, and Clauses

If you are learning SQL, you’ll see different components, and it’s important to understand what they are used for:

  • Statements: Used to carry out tasks in the database
    Examples: SELECT, INSERT, UPDATE, DELETE, ALTER, DROP, CREATE, GRANT, REVOKE
  • Clauses: Components of SQL statements that specify specific conditions, restrictions or operations to be performed
    Examples: SELECT, FROM, WHERE, GROUP BY, HAVING, ORDER BY, LIMIT, OFFSET, JOIN, UNION, WITH
  • Expressions: Combinations of values, operators, and functions that produce a single value
    Examples: mathematical operations, concatenation, Functions, CASE, Subquery
  • Predicates: Conditions that evaluate to either true, false or unknown in SQL. They are used in the WHERE clause of SQL to specify a subset of rows to be returned from a database table
    Examples: Equality, Inequality, Comparison, BETWEEN, LIKE, NULL, AND, OR, NOT
  • Operators: Symbols or keywords used to perform operations and comparisons in SQL expressions
    Examples: Arithmetic, Comparison, Logical, IN, LIKE, BETWEEN, IS NULL
  • Functions: Built-in or user-defined operations that perform specific calculations or manipulations on data. Examples: Aggregates, Date & Time, String, Conversion, Mathematical
  • Data types: Specify and define the type of data that a column in a table can hold
    Examples: Numeric, Characters and Strings, Date & Time, Binary, Boolean
  • Keywords: Special reserved words used in SQL that have a specific meaning and cannot be used as identifiers (such as table or column names) without being quoted
    Examples: SELECT, FROM, WHERE, AND, OR.

You can always write detailed queries using SQL for your desired use case. But if you want to explore making it a little easier on yourself, Coginiti has features to help you analyze your data if you forgot to write the SQL or you’re simply still learning. As an example, Coginiti has an advanced grid to quickly filter, sort, pivot, and aggregate your data.

You can download Coginiti Pro for free to practice your first queries.