Asked 7 years ago
9 Jan 2017
Views 771
sqltreat

sqltreat posted

UPDATE table from SELECT query

how can UPDATE table 's field value from SELECT query in MySQL
shyam

shyam
answered Apr 24 '23 00:00

In SQL, you can use the UPDATE statement with a FROM clause to update a table based on the results of a SELECT query. Here's an example:



UPDATE my_table
SET column1 = new_value
FROM (
  SELECT id, MAX(date) AS latest_date
  FROM my_table
  GROUP BY id
) AS latest_dates

WHERE my_table.id = latest_dates.id AND my_table.date = latest_dates.latest_date;
In this example, we want to update the value of column1 in my_table with a new value. We use a SELECT query to find the latest date for each id in the table, and then join the result of that query with the original table using the FROM clause. Finally, we use a WHERE clause to update only the rows that match the condition of having the latest date for their corresponding id .

It's worth noting that the syntax of SQL may vary depending on the specific database management system you are using.
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