Answer-first summary for fast verification
Answer: When the first statement is run, only rows from the customers table that have at least one match with the orders table on customer_id will be returned. When the second statement is run, only those rows in the customers table that do not have at least one match with the orders table on customer_id will be returned.
The question involves understanding LEFT SEMI JOIN and LEFT ANTI JOIN operations in Databricks SQL. Statement 1 uses LEFT SEMI JOIN, which returns all rows from the left table (customers) that have at least one matching row in the right table (orders) based on customer_id, without returning any columns from the right table. Statement 2 uses LEFT ANTI JOIN, which returns all rows from the left table (customers) that do not have any matching rows in the right table (orders). Option B correctly describes this behavior: the first statement returns customers with orders, and the second returns customers without orders. Other options are incorrect: A describes LEFT/RIGHT OUTER JOINs, C is wrong as the results differ, D is false as Databricks supports these joins, and E incorrectly suggests only customer_id is returned from orders in the first statement.
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Given two SQL statements that produce result sets, how will the result sets differ when each statement is executed in Databricks SQL?
A
The first statement will return all data from the customers table and matching data from the orders table. The second statement will return all data from the orders table and matching data from the customers table. Any missing data will be filled in with NULL.
B
When the first statement is run, only rows from the customers table that have at least one match with the orders table on customer_id will be returned. When the second statement is run, only those rows in the customers table that do not have at least one match with the orders table on customer_id will be returned.
C
There is no difference between the result sets for both statements.
D
Both statements will fail because Databricks SQL does not support those join types.
E
When the first statement is run, all rows from the customers table will be returned and only the customer_id from the orders table will be returned. When the second statement is run, only those rows in the customers table that do not have at least one match with the orders table on customer_id will be returned.