• SQL is a programming language used to interact with a DBMS (Database Management System).
• SQL lets you select, order, sum, and count data.
• SELECT and FROM are the two commands that appear in almost every query — SELECT says what columns you want, FROM says which table.
• WHERE filters rows based on a condition; AND / OR combine multiple conditions.
• Wildcards (* and %) let you match "everything" or "partial text" like names starting with a letter.
• ORDER BY sorts your results (ASC = ascending, DESC = descending).
• SUM adds up a numeric column; COUNT counts how many rows match.

Think of a database table like a giant spreadsheet sitting inside a piece of software called a DBMS (Database Management System) — think MySQL, Oracle, or Microsoft Access working behind the scenes. You can't just "look" at the spreadsheet and pick out rows by eye when it has millions of entries. Instead, you write a short, precise instruction in SQL, and the DBMS does the searching for you and hands back exactly what you asked for.

SQL stands for Structured Query Language. The word "structured" matters — SQL queries always follow a predictable shape (SELECT ... FROM ... WHERE ...), a bit like a sentence template. Once you know the template, you're just filling in the blanks with your own table and column names.

SQL allows a user to do four main things with data:

• Select data — pull out specific rows/columns
• Order data — sort the results
• Sum data — add up a numeric column
• Count data — count how many rows match

Every SQL query that retrieves data starts with these two commands working together. SELECT tells the DBMS which columns you want back. FROM tells it which table to look in. You genuinely cannot write one without the other for a basic query — SELECT on its own doesn't know where to look, and FROM on its own doesn't know what to return.

If you want every column in the table, you don't have to type each one out — you use the wildcard * to mean "all columns."

SELECT * FROM users;
-- retrieves ALL columns from the 'users' table

SELECT name, age
FROM users;
-- retrieves only the 'name' and 'age' columns

SELECT and FROM get you data — but usually you don't want every row, you want specific ones. That's the job of WHERE. It filters rows based on a condition, so only the rows that satisfy that condition are returned.

SELECT * FROM users
WHERE age > 30;
-- only returns users older than 30

Combining conditions: AND vs OR

Often one condition isn't enough — you want rows that satisfy two conditions at once (AND), or rows that satisfy either one (OR). These two keywords behave very differently, and mixing them up is one of the most common exam mistakes.

SQL has two wildcard symbols, and it's easy to muddle them because they look similar in purpose but are used in completely different places.

SELECT * FROM users
WHERE name LIKE 'J%';
-- retrieves users whose name STARTS WITH 'J' (Jane, John, Jake...)

Read 'J%' as: "starts with J, then anything at all can follow." If you wanted names that contain "an" anywhere, you'd write '%an%' — a % on both sides means "anything before, anything after."

By default, a DBMS doesn't guarantee any particular order for the rows it returns. ORDER BY lets you control exactly how the results are sorted — alphabetically, numerically, ascending or descending, and even by more than one column at once (useful for things like "sort by surname, then by first name for people who share a surname").

SELECT Forename, Lastname FROM Students
WHERE StudentID < 10
ORDER BY Lastname, Forename ASC;
-- retrieves forename & lastname of students with ID under 10,
-- sorted ascending by lastname, then by forename as a tie-breaker

ASC = ascending (A→Z, or smallest→largest number). DESC = descending (Z→A, or largest→smallest). If you don't specify either, ASC is usually the default — but in an exam, always write it explicitly to show you know what you're doing.

Sometimes you don't want individual rows back at all — you want a single number that summarises the data. SUM and COUNT are "aggregate functions" — they take many rows and collapse them into one answer.

Below is a table of animals called tbl_animals:

SELECT .................................
FROM .................................
WHERE .................................

• I can explain what SQL is and why it's used with a DBMS
• I can write a basic SELECT ... FROM ... query
• I can use * to select all columns
• I can filter rows using WHERE with a condition
• I know the difference between AND (strict, narrows) and OR (loose, widens)
• I can use % with LIKE to match partial text
• I can sort results using ORDER BY with ASC/DESC
• I can sort by more than one column (tie-breaker logic)
• I can use SUM() to total a numeric column
• I can use COUNT(*) to count matching rows
• I can combine WHERE + AND/OR + ORDER BY in one query