Updating sql server column from another column
These functions are invoked at the time of insert or update if no other value for that column is supplied, and the value returned is used for the column’s value.
Below illustrates a crude “sequence” that assigns an incrementing counter to a primary key column: It should be noted that for real “incrementing sequence” behavior, the built-in capabilities of the database should normally be used, which may include sequence objects or other autoincrementing capabilities.
Thanks, Colby" id="ctl00_m_m_i_ctl00_gr_ctl05_bestanswerbody" class="textarea-bestanswerhidden" name="bestanswerbody" answerbody Id="3916931" / UPDATE TABLE A SET column1=SELECT (column2) FROM A But if source is the same table...
This prevents the UPDATE from trampling over rows where there is no match (usually nulling all the values).
In this case, since a missing question ID would change the NULL to NULL, it arguably doesn't matter.
Above, the value “12” will be bound as the column value during an INSERT if no other value is supplied.
A scalar value may also be associated with an UPDATE statement, though this is not very common (as UPDATE statements are usually looking for dynamic defaults): keyword arguments also accept Python functions.
I had a situation where I need to copy a date value from one column to other columns, and it only applies to SOME of the columns, and not all.