Question

To insert an identical row to a table I use

Insert into table (select * from table where columnA = 'a' and columnB = 'b')

Am I able to insert and change columnB = ‘c’ in one sql?

Answer 1

Yes, just specify the value in the select:

insert into table (ColumnA, ColumnB)
select ColumnA, 'c'
from table
where columnA = 'a' and columnB = 'b'

(If you have more columns, just add them in the column list and the select just like ColumnA.)