SQL CRUD Operations Explained — SELECT, INSERT, UPDATE, DELETE

CRUD Operations: SELECT, INSERT, UPDATE & DELETE

1 min readPublished 22 Jul 2026

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CRUD — Create, Read, Update, Delete — is the everyday work of SQL, mapped to four statements.

Interactive explainer

SQL CRUD Operations

SELECT, INSERT, UPDATE, DELETE — the everyday statements.

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SELECT (Read)

Query data.

SELECT reads rows: SELECT name FROM customers WHERE city='London' ORDER BY name; — WHERE filters, ORDER BY sorts. The command you'll use most.

Check your understanding

1. Which clause is essential with UPDATE and DELETE?

2. Which statement reads data?

Keep learning

CRUD Operations Transactions & ACID Microsoft DP-900

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The four statements

SELECT (Read) — SELECT name FROM customers WHERE city = 'London' ORDER BY name;
INSERT (Create) — INSERT INTO customers (name, city) VALUES ('Ada', 'London');
UPDATE (Update) — UPDATE customers SET city = 'Leeds' WHERE id = 5;
DELETE (Delete) — DELETE FROM customers WHERE id = 5;

The golden rule: always use a WHERE clause with UPDATE and DELETE — without it you change every row. Wrap risky changes in a transaction. SELECT is the one you'll use most, filtered with WHERE and sorted with ORDER BY.

Interview Intelligence

How this topic actually shows up in interviews — and how to demonstrate you understand it.

Why employers ask about this

Writing correct, safe CRUD is the baseline SQL skill every technical role expects.

Technical questions

Write a query to find all London customers, sorted by name.+

SELECT * FROM customers WHERE city = 'London' ORDER BY name;

Behavioural questions

Describe a mistake you caught before it caused harm.+

Show care with destructive operations, e.g. testing a WHERE clause with SELECT first.

Real-world scenarios

“You must update one record but fear affecting others.”+

Expected answer: Test the WHERE with a SELECT first, then run the UPDATE inside a transaction so you can roll back.

Practise in AI Interview™Rehearse these questions, scored.Plan with Career Coach™A personalised path to your goal.Evidence it in Career Passport™Prove this skill to employers.

Employability Intelligence

Where this knowledge takes you — the jobs, skills and certifications it feeds into.

Relevant roles

Data AnalystSoftware DeveloperQA Engineer

Skills you're proving

SQL CRUDWHERE/ORDER BYSafe changes

Recommended certifications

Microsoft DP-900 (Data Fundamentals)Oracle / SQL certifications

Career progression

Databases & SQL → analyst/developer roles.

What employers expect

That you can design a sensible schema and write correct, efficient SQL.

Frequently asked questions

What does CRUD stand for?

Create, Read, Update, Delete — mapped to INSERT, SELECT, UPDATE and DELETE in SQL.

Why always use WHERE with UPDATE/DELETE?

Without it, the statement affects every row in the table — a common and costly mistake.

What clause filters SELECT results?

The WHERE clause; ORDER BY then sorts the results.

Practise what you've learned

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