Update operation is used to modify data in oracle.
This update operation will update only one row of a table.…
INSERT INTO..SELECT statement can be used to insert data into multiple target tables based on certain conditions.
Insert is a DML operation. Usually Insert means when we add rows into tables.
There are various ways rows can be added into tables.
Subqueries are select statements which are part of main select statement.
Subqueries can be used in below clauses of a SELECT statement.
Subqueries are of two types:
Group functions execute on a group of rows and return one result per group. Group functions ignore null values.
COUNT function has 3 variants.
There are two types of SQL functions available in oracle:
Single row function: It works on a single row and returns one result for each row.
Multiple row function:…
We can restrict data in oracle by using WHERE clause in a SQL query. WHERE clause can contain single or multiple condition to restrict data as per user needs.
SQL Statement has the following features:
Projection simply means that whether we want to query a few columns or all columns from a table.
Selection means selecting rows from …
We generally use Joins in oracle to fetch the matching rows from two or more tables.
But if we want fetch those rows which do not have any matching pair in …
Its is a method to retrieve a row by traversing through the index, using index column value specified by the statement.
The index scan first locate the root block of the index. Then it …