On 06/17/2018 12:19 PM, Rv02 wrote:
psql I have two tables , table A and Table b. Table A has list of about 60000 customers ID with all their details and Table B had customer is and age for over 500000 rows of customers.
I going to assume you meant Table B has customer ID and age above. Does Table B have duplicate records for customer ID? If so what I offer below might need to be revised.
I need a query that will take a customer from table a and if that customer exists in table B then insert a yes in a new column in table a. Basically what I want to end up with in table a , is all the customers in this table and if they exist in table B then yes in a column. I.e the final result will be 60000 customers and additional column at the end with yes or no depending if they exist in table B.
For future reference there are examples below that cover this: https://www.postgresql.org/docs/10/static/sql-update.html " UPDATE employees SET sales_count = sales_count + 1 FROM accounts WHERE accounts.name = 'Acme Corporation' AND employees.id = accounts.sales_person; " I would test on a dev database or at least use: BEGIN; ... COMMIT; Untested: BEGIN; UPDATE a set new_column = 'f'; UPDATE a SET new_column = 't' FROM b WHERE a.id = b.id; ROLLBACK or COMMIT depending on outcome of above.
Any help is appreciate it -- Sent from: http://www.postgresql-archive.org/PostgreSQL-general-f1843780.html
-- Adrian Klaver adrian.klaver@xxxxxxxxxxx
