使用单个查询更新多个记录以提高性能

I am having an update query inside a loop which get executed thousands of times.

All goes well but problem is that it takes lot of time for all updates.

If I concatenate/combine all update queries in a single string like this:

$update_query = "";
while(condition)
{
    $update_query = $update_query  . " update table set ... ; ";
}

Then execute $update_query single time, will it be helpful?

Or what else I can do for better performance? Any hint or suggestion?

You can use INSERT ... ON DUPLICATE KEY UPDATE

INSERT INTO table (id, value) VALUES (1, 'value1'), (2, 'value2')
ON DUPLICATE KEY UPDATE
value = VALUES(value)

What you're looking for is a batch update query, something like:

UPDATE mytable
SET myfield = CASE other_field
    WHEN 1 THEN 'value'
    WHEN 2 THEN 'value'
    WHEN 3 THEN 'value'
END 
WHERE id IN (1,2,3)