What is referential integrity?

COBOL SQL Interview Questions

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What is referential integrity?

Referential integrity refers to the consistency that must be maintained between primary and foreign keys, i.e. every foreign key value must have a corresponding primary key value.

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Other Interview Questions

• What RDMS objects are crested with the SQL CREATE statements?
• What RDMS objects are required before you can create a table ?
• In what RDMS object does one first list column names ?
• COBOL SQL Interview Questions
• What is the syntax for a CREATE TABLE statement ?
• Can one add columns to a table after it has been defined?
• Where in a table are added column located ?
• After a table is defined, can columns be removed ?
• Which RDMS objects can you change with the SQL ALTER statements?
• What authority is required to create a table?
• What is minimum authority required for one to create a tablespace?
• When is it necessary to create a table index?
• What is a synonym?
• What is a foreign key?
• What is referential integrity?
• What are the column name qualifiers?
• What is a correlation name?
• What is a results table?
• What is a cursor?
• What is the basic differnce between a join and a union?
• What is normalization and what are the five normal forms?
• What are foreign keys?
• Describe the elements of the SELECT query syntax?
• Explain the use of the WHERE clause?
• What techniques are used to retrieve data from more than one table in a single SQL statement?
• What is a view? Why use it ?
• Explain an outer join ?
• What is a subselect? It is different from a nested select ?
• What is the difference between group by and order by ?
• What keyword does an SQL SELECT statement use for a string search?
• What are some SQL aggregates and other built-in functions?
• How is the SUBSTR keyword used in SQL?
• Explain the EXPLAIN statement?
• What is referential integrity?
• What is a NULL value? What are the pros and cons of using NULLS ?
• What is a synonym? How is it used
• What is an alias and how does it differ from a synonym?
• When can an insert of a new primary key value threaten referntial integrity?
• What is the difference between static and dynamic SQL?
• Compare a subselect to a join?
• What is the difference between IN subselects and EXISTS subselect?
• What is a Cartesian product?
• What is a tuple?
• What is the difference between static and dynamic SQL?
• Any SQL implementation covers data types in couple of main categories. Which of the following are those data types?
• We have a table with a CHARACTER data type field
• What does the term "grant privileges" mean?
• What is an image copy?
• What is meant by an index?
• What is an index key?
• What is a join?
• What is meant by locking?
• What is meant by null?
• What is an object?
• Describe referential integrity?
• Describe a primary key?
• How would you find out the total number of row in a table?
• How do you eliminate duplicate values in SELECT?
• How do you select a row using indexes?
• What are aggregate functions?
• How do you find the maximum value in a column?
• Can you use MAX on a CHAR column?
• My SQL statement SELECT AVG(SALARY) FROM EMP-TABLE yields inaccurate results. why?
• How do you retrieve the first 5 characters of FIRSTNAME column of EMP table?
• How do you concatenate the FIRSTNAME and LASTNAME from EMP table to give a complete name?
• What is the use of VALUE function?
• What is UNION, UNION ALL?
• Suppose I have five SQL SELECT statements connected by UNION/UNION ALL ...
• What is the retriction on using UNION in embedded SQL?
• In the WHERE clause what is BETWEEN and IN?
• Is BETWEEN inclusive of the range values specified?
• What are the wildcard characters ?
• When do you use a LINK statement ?
• What is the meaning of underscore ...
• What do you accomplish by GROUP BY ... HAVING clause ?
• Consider the employee table with column PROJECT nullable. How can you get a list of employees who are not assigned to any project ?
• What is the result of this query if no rows are selected: SELECT SUM(SALARY) FROM EMP WHERE QUAL='MSC'; ?
• Why SELECT * is not preferred in embedded SQL programs ?
• What are correlated subqueries?
• What is a cursor? Why should it be used ?
• How would you retrieve row from a DB2 table in embedded SQL?
• Apart from cursor, what other ways are available to you to retrieve a row from a table in embedded SQL?
• How do you specify and use a cursor in a COBOL program?
• What happens when you say OPEN CURSOR?
• Is DECLARE CURSOR executable?
• Can you have more than one cursor open at any one time in a program?
• When you COMMIT, is the cursor closed?
• When you COMMIT, is the cursor closed?