... mysql performance. Trying to update 5 columns (Passing column name through function) in one table. Otherwise it will do an update on every row of the table (even if its not intended!). How to update millions of records without significantly impacting user experience ? do it for only 100 records and update with this query and check the result. Here is the query to update multiple rows in a single column in MySQL − mysql> UPDATE updateMultipleRowsDemo -> SET StudentMathScore= CASE StudentId -> WHEN 10001 THEN 45 -> WHEN 10002 THEN 52 -> WHEN 10003 THEN 67 -> END -> WHERE StudentId BETWEEN 10001 AND 10003; Query OK, 3 rows affected (0.19 sec) Rows matched: 3 Changed: 3 Warnings: 0 As MySQL doesn’t have inherent support for updating more than one rows or records with a single update query as it does for insert query, in a situation which needs us to perform updating to tens of thousands or even millions of records, one update query for each row seems to be too much.. Reducing the number of SQL database queries is the top tip for optimizing SQL applications. MySQL UPDATE command can be used with WHERE clause to filter (against certain conditions) which rows will be updated. 2. MySQL procedure. This way, only the records that are being updated at any point are locked. But problem is if I update more than about 200-300 rows using this code, my server CPU is 100% loaded and table is stopping update after about 200-300 rows. One common approach used to update a large number of records is to run multiple smaller update in batches. I have a contacts table which has about 200 million rows. Update a million Rows . Reply. […] Reply. The following MySQL statement will update the 'receive_qty' column of newpurchase table with a new value 25 if the value of purch_price is more than 50. The line ‘update Colors’ should be ‘update cte’ in order for the code to work. with this suggestion, Also do the part of 700 million records and check the results. Follow edited Sep 12 '17 at 23:15. MDCCL. Also the speed it pretty good, I still need to test it on a huge table, but for my example a products table isn’t necessarily huge (on average I’d say 1000-10000 rows), so it should be quite efficient in the end. Each "location" entry is stored as a single row in a table. Date de publication : 26 mars 2020 Hello! There is a bug in the batch update code. Probably your problem is with @@ROWCOUNT because your UPDATE stamen always updates records and @@ROWCOUNT never will be equal to 0 . Please find the below update statement. Jon says: August 29, 2019 at 10:53 am. Retrouvez nos offres en PHP ! Share. If you liked this post then you might also like my recent post about Using T-SQL to Insert, Update, Delete Millions of Rows. Improve this question. I use Codeigniter 3.1.11 and have a question. I am using a stored procedure to UPDATE/DELETE the rows one by one, which is taking too long. How does the update command lock records ? If you are wondering. A user's phone sends its location to the server and it is stored in a MySQL database. Batch the rows update only a few of them at the same time; Ensure your row filtering is efficient; Run it with the CLI client . I need to update about 1 million (in future will be much more) rows in MySQL table every 1 hour by Cron. Table contain 10 million records it is running for more than 2 hours and keep on running in SQL Server. 7,800 3 … You can run it in phpMyAdmin or run a mysql_affected_rows after it, you’ll see it affects only the rows that need to be updated. The Problem I've been running a mobile GPS tracking service, MoosTrax (formerly BlackBerry Tracker), for a few years and have encountered a large amount of data in the process.