Definition of cross join - sql, PL-SQL Programming

Assignment Help:

Definition of CROSS JOIN - SQL

Let s = t1 CROSS JOIN t2, where t1 and t2 are table expressions optionally accompanied by range variables. Then:

Note: Here T denotes Table and R denotes Row

The heading Hs of s is the concatenation of the headings of t1 and t2, in that order.
If r1 is a row appearing n1 times in t1 and r2 is a row appearing n2 times in t2, then the row formed by concatenation of r1 and r2 in that order appears n1*n2 times in the body of s.

It follows that the degree of the result is the sum of the degrees of the operands and its cardinality is the product of their cardinalities, as with r1 TIMES r2.

Related Discussions:- Definition of cross join - sql

Parameter modes, Parameter Modes To define the behavior of formal pa...

Parameter Modes To define the behavior of formal parameters you use the parameter modes. The 3 parameter modes, IN, OUT, & IN OUT, can be used with any subprogram. Though, a

EXCEPTION handling, set serveroutput on declare a number(5); b numb...

set serveroutput on declare a number(5); b number(5); c number(5); begin a:=&a; b:=&b; c:=a/b; dbms_output.put_line(c); exception when zero_divide then d

Nested tables versus index-by tables, Nested Tables versus Index-by Tables ...

Nested Tables versus Index-by Tables The Index-by tables and nested tables are just similar. For e.g. They have similar structure and their individual elements are accessed in

Initializing records, Initializing Records The illustration below show...

Initializing Records The illustration below shows that you can initialize a record in its type definition. Whenever you declare a record of the type TimeRec, its 3 fields supp

Triggers, At times, customers make mistakes in submitting their orders and ...

At times, customers make mistakes in submitting their orders and call to cancel the order. Brewbean’s wants to create a trigger that automatically updates the stock level of all pr

Accessing attributes in pl sql, Accessing Attributes: You can refer to ...

Accessing Attributes: You can refer to an attribute only by its name not by its position in the object type. To access or modify the value of an attribute, you can use the dot

Effects of null for multiple assignments - sql, Effects of NULL for Multipl...

Effects of NULL for Multiple Assignments - SQL If the row expression given as the source for a multiple assignment evaluates to NULL, then NULL is assigned to each target. If

Variable declaration - sql, Variable Declaration - SQL SQL's support f...

Variable Declaration - SQL SQL's support for variables is very similar to Tutorial D's, except that the syntax for creating persistent variables-base tables-is quite differen

Parameter aliasing, Parameter Aliasing To optimize the subprogram ca...

Parameter Aliasing To optimize the subprogram call, the PL/SQL compiler can decide between the two techniques of the parameter passing. With the by-value techniques, the v

Cause of indeterminacy in sql, Cause of Indeterminacy in SQL One root ...

Cause of Indeterminacy in SQL One root cause of indeterminacy in SQL lies in its implementation of comparison for equality. For certain system-defined types it is possible for

Write Your Message!

Name

Email id

Message

Verfication Code

User Account

All Pages