Error validating the default for column date
CASCADE/RESTRICT doesn't consider whether the column being dropped is used in any indexes.
When a column is dropped, it is removed from any indexes which contain it.
The LOCKSIZE clause allows you to override row-level locking for the specific table, if your system uses the default setting of row-level locking.
(If your system is set for table-level locking, you cannot change the locking granularity to row-level locking, although allows you to use the LOCKSIZE clause in such a situation without throwing an exception.) To override row-level locking for the specific table, set locking for the table to TABLE.
Each row in Cities is checked -- to make sure it satisfied the constraints.
-- if any rows don't satisfy the constraint, the -- constraint is not added An ALTER TABLE statement causes all statements that are dependent on the table being altered to be recompiled before their next execution.
If you created the table with table-level locking granularity, you can change locking back to ROW with the LOCKSIZE clause in the ALTER TABLE STATEMENT.
For information about why this is sometimes useful, see -- Add a new column with a column-level constraint -- to an existing table -- An exception will be thrown if the table -- contains any rows -- since the newcol will be initialized to NULL -- in all existing rows in the table-- add a new foreign key constraint to the -- Cities table.
You must drop and re-create those views if you wish them to return the new columns.
RESTART WITH is useful for a table that has an identity column that was defined as GENERATED BY DEFAULT and that has a unique key defined on that identity column.
Because GENERATED BY DEFAULT allows both manual inserts and system generated values, it is possible that manually inserted values can conflict with system generated values.
To work around such conflicts, use the RESTART WITH syntax to specify the next value that will be generated for the identity column.
Consider the following example, which involves a combination of automatically generated data and manually inserted data: The identity column has used values 1 through 5 at this point.