In this task you are expected to provide an SQL statement from an english description of what that SQL statement does. The description may include multiple steps but you should only ouput one SQL statement that accomplishes every step. An SQL query works by selecting data from a table where certain conditions apply. A table contains columns where every row in that table must have a value for each column. Every table has a primary key that uniquely identifies each row, usually an id. To choose which columns are returned you specify that after the "SELECT" statement. Next, you use a "FROM" statement to specify what tables you want to select the data from. When you specify a table you can rename it with the "AS" statement. You can reference that table by whatever name follows the "AS" statement. If you want to select data from multiple tables you need to use the "JOIN" statement. This will join the tables together by pairing a row in one table with every row in the other table (Cartesian Product). To limit the number of rows returned you should use the "ON" statement. This will only return rows where the condition specified after the statement is true, this is usually an equals operator with primary keys. You can also use the "WHERE" statement to specify that only rows with column values statisfying a certain condition, should be returned. The "GROUP BY" statement will group rows together that have equal column values for whatever columns follows the statement. The "HAVING" statement will return groups that statisfy whatever condition follows the statement. Any column(s) being returned from grouped rows must either be an aggregate function, (AVG, MAX, COUNT, SUM, ...) of a column, or the column(s) that the data was grouped by. To sort the returned data you can use the "ORDER BY" command which will order the data by whatever aggregate function or column follows the statement. The "DESC" statement will sort in descending order and the "ASC" statement will sort in ascending order. Finally, you can use the "LIMIT" statement to return a certain number of rows. When "*" is used in an SQL statement every column is returned. For example, SELECT * FROM table WHERE attribute = 1, will select every column from rows with the attribute column equal to 1.
--------
Question: Step 1: For each row in Roles table, find the corresponding rows in Users table.
Step 2: find the number of rows of each value of Users's role_code in the results of step 1.
Step 3: find role_description of step 1 results with largest value in the results of step 2

Answer: SELECT T1.role_description FROM Roles AS T1 JOIN Users AS T2 ON T1.role_code = T2.role_code GROUP BY T2.role_code ORDER BY Count ( * ) Desc LIMIT 1


Question: Step 1: For each row in bank table, find corresponding rows in customer table and in loan table.
Step 2: find without repetition cust_name, credit_score of the results of step 1 whose loan_type equals Mortgages

Answer: SELECT DISTINCT T2.cust_name , T2.credit_score FROM bank AS T1 JOIN customer AS T2 ON T2.branch_ID = T1.branch_ID JOIN loan AS T3 ON T1.branch_ID = T3.branch_ID WHERE T3.loan_type = "Mortgages"


Question: Step 1: find the Document_ID of Documents table.
Step 2: For each row in Documents table, find corresponding rows in Ref_Document_Types table and in Documents_with_Expenses table.
Step 3: find Documents_with_Expenses's Document_ID of the results of step 2 whose Document_Type_Name equals CV.
Step 4: show the rows that are in the results of step 1 but not in the results of step 3

Answer:
SELECT T1.Document_ID FROM Documents AS T1 EXCEPT SELECT T3.Document_ID FROM Ref_Document_Types AS T2 JOIN Documents AS T1 ON T2.Document_Type_Code = T1.Document_Type_Code JOIN Documents_with_Expenses AS T3 ON T1.Document_ID = T3.Document_ID WHERE T2.Document_Type_Name = "CV"