Question

The four types of joins or SELECT statements that relational databases allow are listed below. Also listed are the combinations that these statements select from the database tables. Match each join type with its associated selected combination. Instructions: Choose your responses from the drop-down menus below. Responses cannot be used more than once. All left and right table rows, regardless of match Only matching left and right table rows Only matching right table rows but all left table rows Only matching left table rows but all right table rows 1. Inner join 2. Left join 3. Right join 4. Full join

Answer 1

In relational databases, the types of joins such as Inner join, Left join, Right join, and Full join determine how tables are combined.

Step-by-step explanation:

The different types of joins in relational databases correspond to how data from multiple tables is combined based on matching columns. The Inner join selects only the matching rows in both the left and right tables. The Left join (or Left outer join) selects all rows from the left table, and the matching rows from the right table, including rows with no match in the right table which will have NULL values for columns from the right table. The Right join (or Right outer join) is the opposite of a Left join; it selects all rows from the right table, along with the matching rows in the left table. Finally, the Full join (or Full outer join) selects all rows from both the left and the right tables, with NULL values in places where there is no match.

1. Inner join - Only matching left and right table rows.
2. Left join - Only matching right table rows but all left table rows.
3. Right join - Only matching left table rows but all right table rows.
4. Full join - All left and right table rows, regardless of match.

Each type of join has its own use cases depending on the relationship between the tables and the information that is needed. Using different join types can help in organizing and presenting data in a structure best suited for the analysis or reporting at hand.