A special-purpose programming language designed for managing data in relational database management systems. We recommend the SQL server PostgreSQL
- Read 2.5. Querying a Table
- Read 2.6. Joins Between Tables
- Read 2.7. Aggregate Functions
- Read 3.5. Window Functions
- Read 4. SQL Syntax
- Read 4.1. Lexical Structure
- Read 4.2. Value Expressions
- Read 5. Data Definition
- Read 5.1. Table Basics
- Read 5.2. Default Values
- Read 5.3. Constraints
- Read 5.5. Modifying Tables
- Read 6. Data Manipulation
- Read 6.1. Inserting Data
- Read 6.2. Updating Data
- Read 6.3. Deleting Data
- Read 7. Queries
- Read 7.1. Overview
- Read 7.2. Table Expressions
- Read 7.3. Select Lists
- Read 7.4. Combining Queries
- Read 7.5. Sorting Rows
- Read 7.6. LIMIT and OFFSET
- Read 7.7. VALUES Lists
- Read 7.8. WITH Queries (Common Table Expressions)
- Read 9. Functions and Operators
- Read 9.1. Logical Operators
- Read 9.2. Comparison Operators
- Read 9.7.1. LIKE
- Read Subquery Expressions
- Read 11. Indexes
- Read 11.1. Introduction
- Read 11.5. Combining Multiple Indexes
- Read I. SQL Commands
- Read ALTER TABLE
- Read CREATE INDEX [ CONCURRENTLY ]
- Read CREATE TABLE
- Read DELETE
- Read INSERT
- Read SELECT
- Read UPDATE
- Insert a new record.
- Update one or more records.
- Delete one or more records.
- Find rows that satisfy one or more conditions.
- Limit query results.
- Order query results.
- Average values in a column.
- Find the mininum value in a column.
- Find the maximum value in a column.
- Sum values in a column.
- Count values in a column.
- Paginate results.
- Suppress duplicates.
- Answer negation questions. ("Which students don't take course 101?")
- Answer limit questions. ("Which students take at least 2 courses?")
- Answer exact questions. ("Which professors teach only 1 course?")
- Answer relational division questions. ("Find a plane faster than all trains.")