Html table for updating database java
What is being created is instances of the objects, such as a new table, an index on that table or a view on the same table.A database trigger is stored code that is executed immediately after a predefined event.
But by default primary key creates a clustered index on the column, where are unique creates a nonclustered index by default. Triggers are special kind of stored procedures that get executed automatically when an INSERT, UPDATE or DELETE operation takes place on a table. They get triggered only when an associated action (INSERT, UPDATE, DELETE) happens on the table on which they are defined.14) What is a join and explain different types of joins?
Another major difference is that, primary key doesn't allow NULLs, but unique key allows one NULL only. Join is used in queries to explain how different tables are related.
An index is a physical structure containing pointers to the data.
Indices are created in an existing table to locate rows more quickly and efficiently.10) What is GROUP BY?
When connection is closed, the data in the global temporary table disappears.