What is the difference between join and union.
Answer Posted / sompalli krishna
Join: joins are used to combine the columns from one or
more tables(join using one table is possible for self
join).output should B more than one column.
It is constraint based.Columns r joined based on similar
column names and datatypes also on both the tables.
union: union is used to combine the columns from one or
more tables.Output should B one column.
It is not constraint based.Any no. of columns can be
combined without using any condition.But the data types
should be same immaterial to column names.
Contact me for any queries on 09885790989
| Is This Answer Correct ? | 0 Yes | 5 No |
Post New Answer View All Answers
Can we use pl sql in mysql?
What are the possible values that can be stored in a boolean data field?
What are the two types of cursors in pl sql?
explain the options of myisamchk to improve the performance of a table. : Sql dba
Explain unique key in sql.
What is a database event trigger?
Does inner join remove duplicates?
How do I view a view in sql?
Define SQL and state the differences between SQL and other conventional programming Languages?
what is schema? : Sql dba
Can we insert in sql function?
what is foreign key? : Sql dba
How to generate a salary slip like jan 1000 1000 feb 1000 2000 ... dec 1000 12000
What is scalar function in sql?
What is the usage of the distinct keyword?