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SQL Fundamentals
Recap Quiz
Made by
@beamishc
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What does this SQL query do?
1: What does this SQL query do?
30s
Creates a new table with a name column
Filters rows where name is not NULL
Selects only the name column from people
Returns the count of names in the table
Which SQL clause is used to filter rows?
2: Which SQL clause is used to filter rows?
30s
LIMIT
WHERE
HAVING
GROUP BY
What does DISTINCT do in SQL?
3: What does DISTINCT do in SQL?
30s
Returns rows where all columns are unique
Returns only unique values in selected columns
Filters only rows that appear once in the table
Removes NULLs from the output
Which SQL statement adds new rows to a table?
4: Which SQL statement adds new rows to a table?
30s
UPDATE
APPEND
INSERT
ALTER
What is a Primary Key?
5: What is a Primary Key?
30s
To ensure values are never NULL
To uniquely identify each row in a table
To optimize join performance
To define sort order
What does this query return?
6: What does this query return?
30s
All columns for all rows with name exactly “Clara”
Only the name column for Clara
All rows that contain “Clara” in any column
All names starting with “C”
What does CREATE TABLE do?
7: What does CREATE TABLE do?
30s
Inserts new rows into an existing table
Creates a new database
Defines a new table structure
Adds a column to a table
What does INSERT INTO ... SELECT do?
8: What does INSERT INTO ... SELECT do?
30s
Updates existing rows with values from another table
Runs a subquery inside a WHERE clause
Creates a view from a SELECT
Copies data between tables
What does the UPDATE statement do?
9: What does the UPDATE statement do?
30s
Adds a column to a table
Changes the values in one or more existing rows
Renames columns
Filters rows based on a condition
What does IS NULL test for?
10: What does IS NULL test for?
30s
Whether a value is NULL
Whether a value is undefined
Whether a column has an empty string
Whether a key is missing
What is the default sort order of ORDER BY?
11: What is the default sort order of ORDER BY?
30s
Case-insensitive alphabetical
Descending
Ascending
Random
What does ORDER BY 2 mean?
12: What does ORDER BY 2 mean?
30s
Sort using the column in the second position of SELECT
Use the second-largest column
Sort by 2 columns
Return 2 rows
What does this query do?
13: What does this query do?
30s
Returns names that contain the letter “C”
Returns rows with case-insensitive matches for “c”
Returns names that end with “C”
Returns rows where name starts with “C”
What does a CASE WHEN clause allow?
14: What does a CASE WHEN clause allow?
30s
Iterating through rows
Creating loops
Applying conditional logic within SELECT
Joining multiple tables
What does this query do?
15: What does this query do?
30s
Shows total number of children per person
Returns unique values in the number_of_children column
Removes rows with more than one child
Filters only non-null children