Explore Library
Databases & SQLBasic SQL Queries (SELECT, WHERE, ORDER BY)

76 items

1

Filter Aggregates with HAVING

Code Quiz
2

Filtering and Sorting Results

Quiz
3

Core SQL Querying Essentials

Slides / Video
4

Filtering Aggregated Results

Quiz
5

SQL Query Building Blocks

Flashcard
6

Selecting All Columns With The Wildcard

Slides / Video
7

Removing Duplicates With DISTINCT

Quiz
8

String Literals And Quoting

Quiz
9

Range Filtering With BETWEEN

Quiz
10

Selecting All Columns

Quiz
11

Selecting Specific Columns

Quiz
12

Column Aliases With AS

Quiz
13

Filtering With WHERE

Quiz
14

Comparison Operators

Quiz
15

Combining With AND / OR

Quiz
16

Negating With NOT

Quiz
17

Logical Order Of Clauses

Quiz
18

Set Membership With IN

Quiz
19

Pattern Matching With LIKE

Quiz
20

Filtering NULL Values

Quiz
21

Sorting With ORDER BY

Quiz
22

Ascending vs Descending Sort

Quiz
23

Sorting By Multiple Columns

Quiz
24

Limiting Result Rows

Quiz
25

SQL Syntax Basics

Slides / Video
26

Limiting Rows With LIMIT and TOP

Slides / Video
27

Removing Duplicates With DISTINCT

Slides / Video
28

Sorting by Multiple Columns

Slides / Video
29

Ascending and Descending Order

Slides / Video
30

Sorting Results With ORDER BY

Slides / Video
31

Handling NULLs With IS NULL

Slides / Video
32

Set Membership Filtering With IN

Slides / Video
33

Range Filtering With BETWEEN

Slides / Video
34

Pattern Matching With LIKE

Slides / Video
35

Combining Conditions With AND, OR, NOT

Slides / Video
36

SQL Comparison Operators in WHERE

Slides / Video
37

Filtering Rows With WHERE

Slides / Video
38

Renaming Columns With AS Aliases

Slides / Video
39

Specifying Tables With FROM

Slides / Video
40

Selecting All Columns

Code Quiz
41

Selecting Specific Columns

Code Quiz
42

Column Aliases With AS

Code Quiz
43

WHERE Comparison Operator

Code Quiz
44

Combining Conditions

Code Quiz
45

Filtering Ranges With BETWEEN

Code Quiz
46

Filtering With IN

Code Quiz
47

Pattern Matching With LIKE

Code Quiz
48

Handling NULL Values

Code Quiz
49

Sorting With ORDER BY

Code Quiz
50

Sorting Descending

Code Quiz
51

Sorting By Multiple Columns

Code Quiz
52

Removing Duplicates With DISTINCT

Code Quiz
53

Limiting Returned Rows

Code Quiz
54

Clause Order In A Query

Code Quiz
55

Selecting Specific Columns by Name

Slides / Video
56

The SELECT Statement's Purpose

Slides / Video
57

Comparison Operators

Flashcard
58

BETWEEN Operator for Ranges

Flashcard
59

Filtering with IS NULL / IS NOT NULL

Flashcard
60

Ascending vs Descending Sort

Flashcard
61

Selecting Specific Columns

Flashcard
62

Statement Termination with Semicolon

Flashcard
63

ORDER BY for Sorting

Flashcard
64

LIKE Operator and Wildcards

Flashcard
65

Logical Operators AND, OR, NOT

Flashcard
66

Column Aliases with AS

Flashcard
67

LIMIT Clause to Restrict Rows

Flashcard
68

WHERE Clause for Filtering

Flashcard
69

IN Operator for Value Lists

Flashcard
70

Sorting by Multiple Columns

Flashcard
71

String Literals and Quoting

Flashcard
72

Case Sensitivity and Conventions

Flashcard
73

SELECT Statement Basic Syntax

Flashcard
74

FROM Clause and Table Name

Flashcard
75

Selecting All Columns with *

Flashcard
76

SELECT DISTINCT for Unique Values

Flashcard
Code QuizAdvanced

Filter Aggregates with HAVING

Spot the classic mistake of filtering an aggregate result using WHERE instead of HAVING.

Codesql
SELECT department, COUNT(*) AS employee_count
FROM employees
WHERE COUNT(*) > 5
GROUP BY department
ORDER BY employee_count DESC;

This query should return departments with more than 5 employees, but it fails. What is the bug?