{"id":232,"date":"2024-08-23T02:00:12","date_gmt":"2024-08-23T02:00:12","guid":{"rendered":"https:\/\/techkubo.com\/sql\/?p=232"},"modified":"2025-05-12T14:56:30","modified_gmt":"2025-05-12T14:56:30","slug":"sql-left-join","status":"publish","type":"post","link":"https:\/\/techkubo.com\/sql\/sql-left-join\/","title":{"rendered":"SQL Left Join"},"content":{"rendered":"\n

The SQL Left Join or Left Outer Join allows you to retrieve all rows from the left table and the matched rows from the right table.<\/p>\n\n\n\n

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SQL Left Join Syntax<\/h2>\n\n\n\n
SELECT column_list\nFROM left_table\nLEFT JOIN right_table\nON left_table.common_column = right_table.common_column;<\/pre><\/div>\n\n\n\n
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SQL Left Join Retrieving All Patients and Their Appointments Example<\/h2>\n\n\n\n
This query retrieves all patients from the Patients table, even those who do not have a corresponding entry in Appointments table.<\/p>\n\n\n\n
SELECT p.first_name AS "Patient Name", a.appointment_date AS "Appointment Date"\nFROM Patients AS p\nLEFT JOIN Appointments AS a\nON p.patient_id = a.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 Listing All Doctors and Their Patients’ Names<\/h2>\n\n\n\n
This query shows all doctors, even those who currently do not have any patients assigned to them. For doctors without patients, the Patient Name filed will be NULL.<\/p>\n\n\n\n
SELECT d.first_name AS "Doctor Name", p.first_name AS "Patient Name"\nFROM Doctors AS d\nLEFT JOIN Appointments AS a\nON d.doctor_id = a.doctor_id\nLEFT JOIN Patients AS p\nON a.patient_id = p.patient_id;<\/pre><\/div>\n\n\n\n
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SQL Left Join Visual Diagram<\/h2>\n\n\n\n
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SQL Left Join Labs<\/h2>\n\n\n\n