How To Update A Field ?

Hello Everyone,

UPDATE WrongTable
SET WrongTable.employee_name = (
SELECT CorrectTable.employee_name
FROM CorrectTable
WHERE CorrectTable.employee_id = WrongTable.employee_id);

The above script updates Field 1 in Table 1 with the information of Field 2 in Table 2 (both being of the same datatype). At the moment Field 2 basically overwrites all existing data with it's own data, and if it encounters data in Field 1 which it doesn't have an equivalent update it just replaces it with a NULL value (ie. wipes out the original value of Field 1 even if it has none of it's own to update).

My question is, can an addition be made to the above query such that it would leave any existing data in Field 1 if it does not have a value to update it with ?. This is because if Field 1 is NOT NULL type then the query would not run as an error would be reported of an attempt to insert a NULL value into a NOT NULL field.

Also, on a separate note, does anyone have a script to run which would update Fields 1,2, and 3 from Table 1 into Fields 1,2,3 of Table 2 all in one go (i.e., not updating one column at a time, rather one row at a time), does anyone have a handy script for such a task ?. You can assume that Field 1 is the key to join, and also the fields are of the same data types. Thank you so much for your time.

Yours Sincerely,
Angelica Veron,
Faro_at_globalserve.net Received on Sun Jun 27 1999 - 03:24:26 CDT