Chapter4ReviewQuestions
Code example 4-1 SELECT VendorName AS Vendor, InvoiceDate AS Date FROM Vendors AS V JOIN Invoices AS I ON V.VendorID = I.VendorID;
Date
In a cross join, all of the rows in the first table are joined with all of the
rows in the second table
___________________ names can be used when you want to assign a temporary name to a table.
Correlation
When you code a union that combines two result sets, which of the following is not true?
The result sets must be derived from different tables
When you use the implicit syntax for coding inner joins, the join conditions are coded in the ____________ clause.
WHERE
Which of the following is not a reason for using the explicit syntax instead of the implicit syntax for inner joins? The explicit syntax
can be used for more than two tables
When you need to code multiple conditions in a join, its best to
code only join conditions in the ON clause
Code example 4-1 SELECT VendorName AS Vendor, InvoiceDate AS Date FROM Vendors AS V JOIN Invoices AS I ON V.VendorID = I.VendorID;
correlation name table alias
In most cases, the join condition of an inner join uses the _______________ operator to compare two keys.
equal
Code example 4-1 SELECT VendorName AS Vendor, InvoiceDate AS Date FROM Vendors AS V JOIN Invoices AS I ON V.VendorID = I.VendorID; (Refer to code example 4-1.) This join is coded using the _____________________________ syntax.
explicit SQL-92 explicit join
In most cases, the join condition of an inner join compares the primary key of one table to the ____________________ key of another table.
foreign
If you want to join all of the rows in two tables whether or not they are matched, you use a/an _______________ join.
full outer
When you code a union with the INTERSECT keyword to combine two result sets, the union
includes only rows that occur in both result sets
Code example 4-1 SELECT VendorName AS Vendor, InvoiceDate AS Date FROM Vendors AS V JOIN Invoices AS I ON V.VendorID = I.VendorID; (Refer to Code example 4-1) The type of join is called a/an __________________ join.
inner
If you want to join all of the rows in the first table of a SELECT statement with just the matched rows in a second table, you use a/an _______________ join.
left outer
A union combines the rows from two or more _______________________.
queries
You don't ever need to code a right outer join because
right outer joins can be converted to left outer joins
A full outer join includes rows that satisfy the join condition, plus
rows in both tables that don't satisfy the join condition
Code example 4-2 SELECT VendorName, InvoiceNumber FROM Invoices LEFT JOIN Vendors ON Invoices.VendorID = Vendors.VendorID; (Refer to code example 4-2.) The total number of rows returned by this query must equal
the number of rows in the Invoices table
In a join, column names need to be qualified only
when the same names are used in both
If you assign a correlation name to one table in a join,
you have to use that name for the table