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!
Data Definition Language
It organises the data in the form of columns and rows. But what does the data field column of table accumulate? How do you describe it using SQL?
The Data definition language (DDL) defines a set of commands used in the modification and creation of schema objects such as indexes, tables, views etc. These commands give the ability to create, drop and alter these objects. These commands are linked to the management and administrations of the databases. Before and after every DDL statement, the current transactions are implicitly committed, that is changes made by these commands are permanently stored in the databases. Let us talk about these commands in more detail:
CREATE TABLE Command
Syntax:
CREATE TABLE
Column_name1 data type (column width) [constraints], Column_name2 data type (column width) [constraints], Column_name3 data type (column width) [constraints],
...............................................
);
Where table name assigns the name of the table, column name describes the name of the field, data type specifies the data type for the field and column width distribute specified size to the field.
What is self-transition? If there is a transition which goes back to same state, it is known as "self- transition." With a trigger action exit action would be executed f
Explain the Weak Entity Set An Entity set which does not have sufficient attribute to make a primay key is known as weak entity set. For instance, dependents of an employee in
Normal 0 false false false EN-IN X-NONE X-NONE MicrosoftInternetExplorer4
Explain the structure of well formed formulae in relational calculus. Ans: a. An atom is a formula b. If P1 is a formula, after that so are ¬P1 and (P1) c. If P1 and P2 a
Question (a) Differentiate between the following terms: (i) Distributed Database v/s Distributed Database management System (ii) Homogeneous Distributed Database v/s Hete
Determine the term- Active values An active value is that has dependent values. Every dependent value registers itself with active value that contains a set of dependent values
What is the main advantage of the object model? What are its different components? The object model focuses on the logical data structures. Each object model comprises of many
The indices are accumulated in the index files. The data is accumulated in the data files. Indices give fast access to data items. For example, a book database may be managed in th
Atomicity : Either all functions are laid out or none are. Users could not have to think about the effect of incomplete operations. DBMS ensures this by undoing the functions
Discuss the problem of Spurious tuples and how we may prevent it. Ans: A spurious tuple is, mainly, a record in a database that gets created while two tables are joined bad
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