For question 138 regarding Oracle views, the correct answers are B, E, and G:
* B. The WITH CHECK OPTION clause prevents certain rows from being updated or inserted:
This clause ensures that all data modifications performed through the view result in data that conforms to the view's defining query.
* E. Deleting one or more rows using a view whose defining query contains a GROUP BY clause will cause an error: Views that involve aggregate functions, GROUP BY clauses, or DISTINCT cannot be directly modified with DML operations such as DELETE, because the underlying data manipulation would be ambiguous.
* G. Inserting one or more rows using a view whose defining query contains a GROUP BY clause will cause an error: Similarly to DELETE, INSERT operations into a view that uses a GROUP BY clause are generally not allowed because it's unclear how the new rows should be aggregated into the existing groups.
Other options are incorrect because:
* A: The WITH CHECK OPTION clause does not prevent rows from being displayed; it restricts DML operations.
* C: Views can be created with non-existent underlying tables or views using the FORCE option in Oracle.
* D: Not all views are updatable, especially those involving joins, group functions, or distinct aggregation.
* F: Updating a view does not impact the granted privileges unless the definition of the view changes.

In SQL, to return all rows from one table in a join regardless of whether they match rows in the other table, a LEFT JOIN is used when we want all rows from the left table, or a RIGHT JOIN when we want all rows from the right table. Here's an explanation for each query provided in the context of the COLORS and BRICKS tables:
A). This query uses a LEFT JOIN and will return all the rows from the COLORS table (c) because it is on the left side of the join. Additionally, it joins the BRICKS table (b) on the condition that the color_rgb_hex_value matches. The condition in the WHERE clause (b.brick_id > 0) will not exclude any COLORS rows because it only filters the rows from the right table (BRICKS) after the join.
B). This query uses a RIGHT JOIN, and while it does return all rows from the COLORS table, it doesn't place it on the left side of the join, which is not what is typically expected from a RIGHT JOIN to return all rows from the right side table.
C). This query is a plain JOIN (also known as an inner join), which only returns rows that have matching values in both tables, so it will not return all the rows from the COLORS table if there is no match in the BRICKS table.
D). This query uses a FULL JOIN, which returns all rows when there is a match in one of the tables. Hence, it will return all the rows from both the COLORS and BRICKS tables. While this does return all rows from the COLORS table, it also includes all rows from the BRICKS table, which may not be desired if the requirement was only to return all rows from COLORS.
E). This query is similar to option A and uses the USING clause to specify the join condition. The USING clause is used when both tables have a column with the same name and is meant to simplify the syntax.
However, in this case, the columns do not have the same name in both tables (RGB_HEX_VALUE in COLORS and COLOR_RGB_HEX_VALUE in BRICKS), so this query will not execute successfully.
References:
* Oracle Database SQL Language Reference, 12c Release 1 (12.1): "Joins"
* Oracle Database SQL Language Reference, 12c Release 1 (12.1): "LEFT OUTER JOIN"
* Oracle Database SQL Language Reference, 12c Release 1 (12.1): "RIGHT OUTER JOIN"
* Oracle Database SQL Language Reference, 12c Release 1 (12.1): "FULL OUTER JOIN"
Based on the explanations above, the correct answers that return all rows from the COLORS table are A and D: However, D includes all rows from BRICKS as well, which may not be the intended requirement if the question specifies only rows from COLORS should be returned. Thus, A is the most accurate answer to the question as it adheres to the standard expectation of a LEFT JOIN.