Join vs Union in SQL Databases

Join and Union are two commonly used operations in databases, each serving different purposes and use cases.

1. Come and be a part of it.

1. “Join is an operation used to combine data from two or more tables.”
2. The Join operation matches and combines rows from tables based on the specified relationship conditions, creating a new resulting set.
3. The Join operation can achieve different data relationships based on various association conditions such as inner join, left join, right join, and outer join.
4. The Join operation is often used in scenarios where queries require associating data between multiple tables, allowing flexibility to link tables based on business requirements.

1. The association/federation.

1. The Union operation is used to combine two or more query result sets.
2. The Union operation combines all the records from multiple query results into one result set, removing any duplicate records.
3. The Union operation requires the merged result set to have the same number of columns and data types, otherwise an error will occur.
4. The Union operation is commonly used to merge multiple query results into one result, such as combining and displaying results from different conditions.

In general, the Join operation is used to combine data from related tables by matching them based on specified conditions, while the Union operation is used to merge multiple query result sets into one. The two operations have different purposes and scenarios, so it is important to choose the appropriate one based on specific needs.