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!
CHECK Constraints in SQL
A CHECK constraint is a table constraint defined using the key word CHECK, as already illustrated in several examples in this chapter. In particular, a CHECK constraint can be used to express a constraint such as the one shown in Example, referred to in the theory book as a tuple constraint (so one might call it a row constraint in SQL). This is clearly the way most SQL users would prefer to express such a constraint.
Role of Abstraction in pl/sql: The abstraction is a high-level description or model of a real-world entity. The Abstractions keep our daily lives convenient. They help us ca
Example of ADD CONSTRAINT in SQL Example: Alternative formulation for MAX_ENROLMENTS ALTER TABLE IS_ENROLLED_ON ADD CONSTRAINT MAX_ENROLMENTS CHECK ((SELECT COUNT (*)
Name Resolution In potentially uncertain SQL statements, the names of the database columns take precedence over the names of the local variables and formal parameters. For e.g.
Aggregate Operators SQL Supports all of the aggregate operators mentioned in the theory book and many more besides. The syntax, however, involves an unusual trick that SQL cal
TTITLE and BTITLE are commands in Pl-SQL to control report headings and footers. This Ttitle & Btitle are mainly used on creating SQL*PLUS report. Ttitle is used for toptitle headi
Disjunction (OR, ∨) Again we have nine rows instead of just four and again, when unknown is not involved, the rows are as for 2VL. Also, when anything is paired with true, t
Effects of NULL in Table Literal When a VALUES expression appears as the source value for an SQL INSERT statement, the key word NULL can appear as a field value, such that for
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
Grouping and Ungrouping in SQL Example specifying EXAM_MARK in place of COURSE in the main FROM clause. Example: Obtaining C_ER2 from EXAM_MARK SELECT CourseId, CAST
Keyword and Parameter Description: boolean_expression: This is an expression which results the Boolean value TRUE, FALSE, & NULL. It is related with a series of statement
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: +91-977-207-8620
Phone: +91-977-207-8620
Email: [email protected]
All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd