{"id":247,"date":"2024-08-23T02:09:39","date_gmt":"2024-08-23T02:09:39","guid":{"rendered":"https:\/\/techkubo.com\/sql\/?p=247"},"modified":"2025-05-13T13:29:07","modified_gmt":"2025-05-13T13:29:07","slug":"sql-group-by","status":"publish","type":"post","link":"https:\/\/techkubo.com\/sql\/sql-group-by\/","title":{"rendered":"SQL Group By"},"content":{"rendered":"\n

The GROUP BY<\/code> statement groups rows with common values into summary rows. It is typically used with aggregate functions like COUNT()<\/code>, SUM()<\/code>, AVG()<\/code>, MIN()<\/code>, and MAX()<\/code>.<\/p>\n\n\n\n

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SQL Group By Syntax<\/h2>\n\n\n\n
SELECT column_name(s)\nFROM table_name\nWHERE condition\nGROUP BY column_name(s)\nORDER BY column_name(s);<\/pre><\/div>\n\n\n\n
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SQL Group By Example<\/h2>\n\n\n\n
Count patients by gender:<\/h4>\n\n\n\n
Using the Patients<\/code> table, we can count how many patients belong to each gender.<\/p>\n\n\n\n
SELECT gender, COUNT(patient_id) AS total_patients\nFROM Patients\nGROUP BY gender;<\/pre><\/div>\n\n\n\n
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Try It Out!<\/a><\/div>\n<\/div>\n\n\n\n
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Count medical records per patient:<\/h4>\n\n\n\n
This retrieves the number of medical records associated with each patient.<\/p>\n\n\n\n
SELECT patient_id, COUNT(record_id) AS total_records\nFROM MedicalRecords\nGROUP BY patient_id;<\/pre><\/div>\n\n\n\n
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SQL GROUP BY with JOIN Example<\/h2>\n\n\n\n
Count appointments per doctor:<\/h4>\n\n\n\n
To analyze appointment counts for each doctor, we join the Appointments<\/code> and Doctors<\/code> tables:<\/p>\n\n\n\n
SELECT Doctors.first_name || ' ' || Doctors.last_name AS doctor_name, COUNT(Appointments.appointment_id) AS total_appointments\nFROM Appointments\nLEFT JOIN Doctors ON Appointments.doctor_id = Doctors.doctor_id\nGROUP BY doctor_name;<\/pre><\/div>\n\n\n\n
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SQL Group By Visual Diagram<\/h2>\n\n\n\n
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SQL Group By Labs<\/h2>\n\n\n\n