SQLite Forum

Update records in a table based on selection in another table
I’m very very new to SQL 
I have records in a table where I want one field to reflect the value 
Of another field but only on the records that I have selected in connection with 
Another table 
I.e in table B I have one date field 1 and date field 2. 
I want to update date field 2 with value of date field 1 but
Only on records I have selected from table A  I .e records with a status of
Confirmed only. 
I cannot see a matching Id between table a and table b