Apache Derby – Having Clause The HAVING Clause enables you to specify conditions that filter which group results appear in the results. The WHERE clause places conditions on the selected columns, whereas the HAVING clause places conditions on groups created by the GROUP BY clause. Syntax Following is the syntax of the HAVING clause − […]

Apache Derby – Alter Table Statement The ALTER TABLE statement, allows you to alter an existing table. Using this you can do the following − Add a column, add a constraint Drop a column, drop a constraint Change the row level locking of a table Let us assume we have created a table named Employees […]

Apache Derby – Derby Indexes An index in a table is nothing but a pointer to its data. These are used to speed up the data retrieval from a table. If we use indexes, the INSERT and UPDATE statements get executed in a slower phase. Whereas SELECT and WHERE get executed with in lesser time. […]