Already have an account? Get multiple benefits of using own account!
Login in your account..!
Remember me
Don't have an account? Create your account in less than a minutes,
Forgot password? how can I recover my password now!
Enter right registered email to receive password!
Operators on Tables and Rows
Row Extraction
TUPLE FROM r, SQL has row subqueries. These are just like scalar subqueries except that they may specify more than one column. For example, when appearing in a suitable context, the expression
(SELECT * FROM COURSE WHERE CourseId = CID ('C1'))
Yields the row denoted by
CAST (ROW ('C1', 'Database') AS
ROW (CourseId CID, Title VARCHAR (100)))
A row subquery whose table operand is empty yields a row in which every field is NULL.
Field Extraction: For extracting a field from a row, using dot qualification.
Using EXISTS The EXISTS(n) returns TRUE if the nth element in a collection exist. Or else, EXISTS(n) returns FALSE. Primarily, you use EXISTS with DELETE to maintain the spars
Procedures The procedure is a subprogram which can take parameters and be invoked. Normally, you can use a procedure to perform an action. The procedure has 2 sections: the spe
Keyword and Parameter Description select_statement: This is a query which returns a result set of the rows. Its syntax is such that of select_ into_statement without the IN
Providing Results of Queries Expressing queries in SQL is the (big) subject. Here I present just a simple example to give you the flavour of things to come in those chapters.
Exceptions An exception is the runtime error or warning condition that can be predefined or user-defined. The Predefined exceptions are raised implicitly through runtime system
Write a cursor to open an employee database and fetch the employee record whose age is greater than 45
Using Pragma RESTRICT_REFERENCES: The function called from the SQL statements should obey certain rules meant to control the side effects. To check for violation of the rules,
Using Subqueries A subquery is a query (typically enclosed by parentheses) that appears within another SQL data manipulation statement. If evaluated, the subquery gives a va
DELETE Statement The DELETE statement eliminates whole rows of data from the specified table or view. Syntax:
"Not Enforced" Table Constraints A constraint that is not enforced is not really a constraint within the meaning of the act, but SQL does have such a concept and it needs to b
Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!
whatsapp: +1-415-670-9521
Phone: +1-415-670-9521
Email: [email protected]
All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd