📘 SQL Blog Series – 4

Today, we’re going to understand how to fetch data based on specific requirements using different SQL clauses and filters.

These filters help us control what kind of data we want to see from a table instead of showing everything.

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🔹 WHERE Clause

The WHERE clause is used to filter rows based on a specific condition. It tells the database to return only the records that satisfy that condition. Without the WHERE clause, SQL will show all the data from the table.

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🔹 Equal to (=)

The equal-to operator is used to match values exactly. It returns the records where the column value is the same as the value we specify.

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🔹 Greater than (>) and Less than (<)

These operators are used to compare values numerically.

• The greater-than sign is used to find records with values higher than the given number.

• The less-than sign is used to find records with values lower than the given number.

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🔹 IN Clause

The IN clause is used when we want to match a column with multiple values. Instead of writing multiple OR conditions, we can use IN to check if a value exists within a given list.

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🔹 NOT IN Clause

The NOT IN clause is the opposite of IN. It is used to exclude certain values from the result. It returns all records except the ones that match the listed values.

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🔹 BETWEEN Clause

The BETWEEN clause is used to filter data within a specific range. It includes both the starting and ending values in that range.

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🔹 ORDER BY Clause

The ORDER BY clause is used to sort the result set based on one or more columns. It helps organize data in a specific order, making it easier to analyze.

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🔹 ASC and DESC

These are sorting directions used with ORDER BY.

• ASC means ascending order — from smallest to largest or alphabetically from A to Z.

• DESC means descending order — from largest to smallest or alphabetically from Z to A.

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By using these clauses together, we can easily control what data we fetch, how it’s filtered, and in what order it’s displayed. They make data retrieval efficient, flexible, and more meaningful.

In the below video, we’ll explore SQL filters and clauses like WHERE, IN, NOT IN, BETWEEN, and ORDER BY with ASC and DESC.
Watch carefully — but remember, true understanding comes from practice, not just watching.