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Databases and SQL

From zero to writing your own queries — retrieve, combine and manage data with SQL

18 lessons Lesson 1.1 is free to view
Lesson 1.1 is free. Read it first — then decide.
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1

What is a database (and why SQL)?

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○ 1.1 What is a database, really? Free ○ 1.2 Rows, columns and data types 🔒 ○ 1.3 SQL: one language for every database 🔒
2

Retrieving data: SELECT

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○ 2.1 Your first query: SELECT ... FROM 🔒 ○ 2.2 Choosing, renaming and calculating columns 🔒 ○ 2.3 Counting and limiting rows 🔒
3

Filtering, sorting and grouping

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○ 3.1 Filtering with WHERE 🔒 ○ 3.2 Sorting and picking the top 🔒 ○ 3.3 Totalling per group 🔒
4

Combining multiple tables

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○ 4.1 Why data is split across tables 🔒 ○ 4.2 Joining tables with JOIN 🔒 ○ 4.3 LEFT JOIN and missing data 🔒
5

Changing data and designing a table

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○ 5.1 Adding, changing, deleting 🔒 ○ 5.2 Creating a table 🔒 ○ 5.3 Good design: keys and normalising 🔒
6

Speed, safety and practice

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○ 6.1 Fast queries with indexes 🔒 ○ 6.2 Running queries safely 🔒 ○ 6.3 Backups, migrations and learning more 🔒