Create mysql.sql

Author: Deepak-Vohra

sql-queries-12/updating-rows-subquery-referencing-same-table/mysql.sql

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+-- Using a Self Join
+UPDATE Program AS P1
+JOIN (
+    SELECT id, DATE_ADD(start_date, INTERVAL 3 WEEK) AS new_end_date
+    FROM Program
+) AS P2
+ON P1.id = P2.id
+SET P1.end_date = P2.new_end_date;
+
+-- Using a Derived Table
+UPDATE Program
+SET end_date = (
+    SELECT new_end_date FROM (
+        SELECT DATE_ADD(start_date, INTERVAL 3 WEEK) AS new_end_date
+        FROM Program AS Temp
+        WHERE Temp.id = Program.id
+    ) AS Temp_table
+);