Can Check constraint be used for self referential integrity ? How ?

1 Answer

Answer :

? Yes. In the CHECK condition for a column of a table, we can reference some other  column of the same table and thus enforce self referential integrity.

Related questions

Description : What are the Referential actions supported by FOREIGN KEY integrity constraint?

Last Answer : UPDATE and DELETE Restrict – A referential integrity rule that disallows the update or deletion of referenced data. DELETE Cascade – When a referenced row is deleted all associated dependent rows are deleted.

Description : • Describe Referential Integrity?

Last Answer : A rule defined on a column (or set of columns) in one table that allows the insert or update of a row only if the value for the column or set of columns (the dependent value) matches a ... data and the action to be performed on dependent data as a result of any action on referenced data.

Description : What are the Referential actions supported by FOREIGN KEY integrity constraint ?

Last Answer : UPDATE and DELETE Restrict - A referential integrity rule that disallows the update or deletion of referenced data. DELETE Cascade - When a referenced row is deleted all associated dependent rows are deleted.

Description : . ………………… is a special type of integrity constraint that relates two relations & maintains consistency across the relations. A) Entity Integrity Constraints B) Referential Integrity Constraints

Last Answer : B) Referential Integrity

Description : The student marks should not be greater than 100. This is (A) Integrity constraint (B) Referential constraint (C) Over-defined constraint (D) Feasible constraint

Last Answer : (A) Integrity constraint

Description : In RDBMS, the constraint that no key attribute (column) may be NULL is referred to as: (A) Referential integrity (B) Multi-valued dependency (C) Entity Integrity (D) Functional dependency

Last Answer : (C) Entity Integrity

Description : Can you call a stored function in the constraint of a table ?

Last Answer : no

Description : What is difference between UNIQUE constraint and PRIMARY KEY constraint?

Last Answer : A column defined as UNIQUE can contain Nulls while a column defined as PRIMARY KEY can’t contain Nulls. 47.What is Index Cluster? – A Cluster with an index on the Cluster Key 48.When does a Transaction end? – When it is committed or Rollbacked.

Description : What is an Integrity Constrains?

Last Answer : An integrity constraint is a declarative way to define a business rule for a column of a table.

Description : Give two examples of referential integrity constraints.

Last Answer : rential integrity constraints.

Description : Describe Referential Integrity ?

Last Answer : A rule defined on a column (or set of columns) in one table that allows the insert or update of a row only if the value for the column or set of columns (the dependent value) matches a value ... data and the action to be performed on dependent data as a result of any action on referenced data.

Description : What is Referential Integrity ?

Last Answer : Maintaining data integrity through a set of rules that restrict the values of one or more columns of the tables based on the values of primary key or unique key of the referenced table.

Description : How can you Enforce Referential Integrity in snapshots ?

Last Answer : Time the references to occur when master tables are not in use. Peform the reference the manually immdiately locking the master tables. We can join tables in snopshots by creating a complex snapshots that will based on the master tables.

Description : Which if the following is not the type of data integrity. A) Key integrity B) Domain integrity C) Entity integrity D) Referential integrity

Last Answer : A) Key integrity

Description : What is an Integrity Constraint ?

Last Answer : Integrity constraint is a rule that restricts values to a column in a table.

Description : Do you enjoy self referential or self-denying loops?

Last Answer : Pulling the rug out from under me will cause me to slit my own throat!

Description : How many rows will the following SQL return

Last Answer : Select * from emp Where rownum < 10; 9 rows.

Description : Can you use %RowCount as a parameter to a cursor

Last Answer : Yes

Description : What are the various types of RollBack Segments ?

Last Answer : Public Available to all instances Private Available to specific instance

Description : Can you pass a parameter to a cursor ?

Last Answer : Explicit cursors can take parameters, as the example below shows. A cursor parameter can appear in a query wherever a constant can appear. CURSOR c1 (median IN NUMBER) IS SELECT job, ename FROM emp WHERE sal > median

Description : What is the significance of the & and && operators in PL SQL ?

Last Answer : The & operator means that the PL SQL block requires user input for a variable. The && operator means that the value of this variable should be the same as inputted by the user previously ... span across different rollback segments or will it terminate ? It will terminate (Please check ).

Description : What is the maximum no. of columns a table can have ?

Last Answer : 254.

Description : Can you Rollback to any savepoint ?

Last Answer : Yes.

Description : Can you define multiple savepoints ?

Last Answer : Yes.

Description : An insert statement followed by a create table statement followed by rollback ? Will the rows be inserted ?

Last Answer : No.

Description : What is the difference between unique key and primary key ?

Last Answer : Unique key can be null; Primary key cannot be null.

Description : What are the states of a rollback segment ? What is the difference between partly available and needs recovery ?

Last Answer : The various states of a rollback segment are : ONLINE, OFFLINE, PARTLY AVAILABLE, NEEDS RECOVERY and INVALID.

Description : What are the min. extents allocated to a rollback extent ?

Last Answer : Two

Description : Can null keys be entered in cluster index, normal index ?

Last Answer : Yes.

Description : Can Long/Long RAW be clustered ?

Last Answer : No.

Description : What are the disadvantages of clusters ?

Last Answer : The time for Insert increases.

Description : What are the advantages of clusters ?

Last Answer : Access time reduced for joins.

Description : What is the use of Data Dictionary ?

Last Answer : Used by Oracle to store information about various physical and logical Oracle structures e.g. Tables, Tablespaces, datafiles, et

Description : What is the use of Control files ?

Last Answer : Contains pointers to locations of various data files, redo log files, etc.

Description : Can you increase the size of datafiles ? How ?

Last Answer : No (for Oracle 7.0)

Description : Can you increase the size of a tablespace ? How ?

Last Answer : Yes, by adding datafiles to it.

Description : Describe Oracle database's physical and logical structure

Last Answer : Physical : Data files, Redo Log files, Control file. Logical : Tables, Views, Tablespaces, etc.

Description : What are constraining triggers ?

Last Answer : A trigger giving an Insert/Updat e on a table having referential integrity constraint on the triggering table.

Description : What are mutating triggers ?

Last Answer : A trigger giving a SELECT on the table on which the trigger is written.

Description : What are cascading triggers? What is the maximum no of cascading triggers at a time?

Last Answer : When a statement in a trigger body causes another trigger to be fired, the triggers are said to be cascading. Max = 32.

Description : Can views be specified in a trigger statement ?

Last Answer : No

Description : What is the maximum no. of statements that can be specified in a trigger statement?

Last Answer : One.

Description : What is the advantage of a stored procedure over a database trigger ?

Last Answer : We have control over the firing of a stored procedure but we have no control over the firing of a trigger.

Description : What are the various types of database triggers ?

Last Answer : There are 12 types of triggers, they are combination of : Insert, Delete and Update Triggers. Before and After Triggers. Row and Statement Triggers. (3*2*2=12)

Description : What are the parts of a database trigger ?

Last Answer : The parts of a trigger are: A triggering event or statement A trigger restriction A trigger action

Description : Can you pass parameters in packages ? How ?

Last Answer : Yes. You can pass parameters to procedures or functions in a package.

Description : Why Create or Replace and not Drop and recreate procedures ?

Last Answer : So that Grants are not dropped.

Description : What are the constructs of a procedure, function or a package ?

Last Answer : The constructs of a procedure, function or a package are : variables and constants cursors exceptions

Description : Can 2 functions have same name & input parameters but differ only by return datatype

Last Answer : No.