{"id":509,"date":"2024-08-30T01:59:23","date_gmt":"2024-08-30T01:59:23","guid":{"rendered":"https:\/\/techkubo.com\/sql\/?p=509"},"modified":"2025-06-03T11:26:38","modified_gmt":"2025-06-03T11:26:38","slug":"left-join","status":"publish","type":"post","link":"https:\/\/techkubo.com\/sql\/left-join\/","title":{"rendered":"LEFT JOIN"},"content":{"rendered":"\n

SQL LEFT JOIN Keyword<\/h2>\n\n\n\n

The LEFT JOIN command is used to return all rows from the left table, and the matched rows from the right table. If there is no match, the result is NULL from the right side.<\/p>\n\n\n\n

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SQL LEFT JOIN Syntax<\/h2>\n\n\n\n
SELECT column_names\nFROM table1\nLEFT JOIN table2\nON table1.column_name = table2.column_name;<\/pre><\/div>\n\n\n\n
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SQL LEFT JOIN Patients and Appointments Example<\/h2>\n\n\n\n
This query returns all patients, including those who may not have any appointments. If no match is found in the Appointments table, the related columns return NULL.<\/p>\n\n\n\n
SELECT Patients.first_name, Appointments.appointment_id\nFROM Patients\nLEFT JOIN Appointments ON Patients.patient_id = Appointments.patient_id;<\/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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SQL LEFT JOIN Prescriptions and Appointments Example<\/h2>\n\n\n\n
This query shows all appointments and their corresponding prescriptions (if any). Appointments without a prescription will still be shown.<\/p>\n\n\n\n
SELECT Appointments.appointment_id, Prescriptions.prescription_id\nFROM Appointments\nLEFT JOIN Prescriptions ON Appointments.appointment_id = Prescriptions.appointment_id;<\/pre><\/div>\n\n\n\n
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SQL LEFT JOIN Labs<\/h2>\n\n\n\n