copy one column from one table to another

Question

I am confused about how to copy a column from one table to another table using where. I wrote SQL query but it says transaction lock time exceeded or query returns more than one row.
using mysql
Basically,
I have:

Table 1:  Results BuildID  platform_to_insert  Table 2:  build BuildID correct_platform  update results set results.platform_to_insert       = (select correct_platform from          build where results.BuildID = build.BuildID) 

Answer 1

I do not believe you need a sub query.

UPDATE results, build SET    results.platform_to_insert = build.correct_platform WHERE  results.BuildID = build.BuildID