The difference between having and where in oracle

The difference between HAVING and WHERE clauses is that HAVING is used to filter aggregate results (that is, grouped data), while WHERE is used to filter rows in the base table or view. Additionally, HAVING requires the data to be grouped, while WHERE does not.

The difference between HAVING and WHERE clauses in Oracle

Introduction
HAVING and WHERE are two clauses used in Oracle to filter data results. Although they all have similar purposes, they have different application scenarios and functions.

Application scenarios

• WHERE clause: Filter rows in the base table or view.
• HAVING clause: Filter the results of aggregate functions (such as SUM, COUNT), usually used to filter grouped data.

Grammar
WHERE clause:

SELECT column(s) FROM table WHERE condition(s)

HAVING clause:

SELECT column(s)
FROM table
GROUP BY column(s)
HAVING condition(s)

Function comparison

Example

WHERE clause example:

SELECT * FROM customers WHERE country = 'USA';

HAVING clause example:

SELECT country, COUNT(*) AS customer_count
FROM customers
GROUP BY country
HAVING customer_count > 1000;

Conclusion

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