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JOINs
JOINs A JOIN combines rows from two tables using a shared column, like student_id. INNER JOIN : only matching rows. LEFT JOIN : all rows from the left table, even with no match. UNION adds one query’s results to another. Attackers use UNION SELECT username, password FROM users to pull data from anot
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What this card says
What it is
A JOIN combines rows from two tables using a shared column, like student_id.
Types
INNER JOIN: only matching rows. LEFT JOIN: all rows from the left table, even with no match.
Why it matters for security
UNION adds one query’s results to another.
Attackers use UNION SELECT username, password FROM users to pull data from another table. UNION needs the same number of columns.
Learn more in the lesson: 10.9 JOINs