TSQL: Update Table From Another Table

Thank you for splendid instruction, old but gold video

Thankyou Very much

Assalaamualaikum, I need your help sir
I have two table StockIn(This is use for storing every record) records and StockMst(This table for update qty for same product)
when click on button update existing record qty and also i want to insert that record in StockIn table (But in this table i want to insert only company name, item name, type, qty using text boxes, but in address column i want to copy existing address with i already stored for same company not by using text box.

mySQL seem doesn't support "FROM" in UPDATE syntax :< it appears error whenever I type FROM in

I need some help. I have a client table with 3 fields that will need updated. table 1 has client info and the fields needing updated are date, Session and amount.
Now I think I need a form and maybe a table to input the change. For example if client does 1 work out how can I get the detail table to subtract 1 from sessions (in client table. Then when they buy more I need to be able to update table Client with Date paid, amount paid and number of sessions they paid for. HELP !!! and thanks

This was very helpful. Your tips helped me re-write an old cursor based stored procedure and cut the processing time from about 50 seconds to under a second!

thanks a million , you saved my life :D :D

very helpful for me, thaks a lots, saved my job.👍