What is the basic differnce between a join and a union?

COBOL SQL Interview Questions

(Continued from previous question...)

What is the basic differnce between a join and a union?

A join selects columns from 2 or more tables. A union selects rows

(Continued on next question...)

Other Interview Questions

• What is a correlation name?
• Is DECLARE CURSOR executable?
• What RDMS objects are crested with the SQL CREATE statements?
• What is an index key?
• What is meant by an index?
• When is it necessary to create a table index?
• What are aggregate functions?
• What are foreign keys?
• What are some SQL aggregates and other built-in functions?
• How do you concatenate the FIRSTNAME and LASTNAME from EMP table to give a complete name?
• More...