Many-to-Many Relationships and Python >> Using Databases with Python
*Please Wait 15 Seconds To Get The Pdf Loaded
* Please Disable Internet Download Manager (IDM) To View This Pdf.
Many-to-Many Relationships and Python
How do we model a many-to-many relationship between two database tables?
We add 10 foreign keys to each table with names like artict_id_1, artist_id2, etc.
We use a BLOB column in both tables
We add a table with two foreign keys
We use the ARRAY column type in both of the tables
In Python, what is a database “cursor” most like?
A method within a class
A file handle
A Python dictionary
What method do you call in an SQLIte cursor object in Python to run an SQL command?
In the following SQL,
what is the purpose of the “?”?
It is a search wildcard
It allows more than one boolean operation in the WHERE clause
It is a syntax error
It is a placeholder for the contents of the “org” variable
In the following Python code sequence (assuming cur is a SQLite cursor object),
what is the value in row if no rows match the WHERE clause?
An empty list
An empty dictionary
What does the LIMIT clause in the following SQL accomplish?
It only retrieves the first 10 rows from the table
It only sorts on the first 10 characters of the column
It reverses the sort order if there are more than 10 rows
It avoids reading data from any table other than Counts
What does the executescript() method in the Python SQLite cursor object do that the normal execute() method does not do?
It allows embeded Python to be executed
It allows multiple SQL statements separated by semicolons
It allows database tables to be created
What is the purpose of “OR IGNORE” in the following SQL:
It makes sure that if a particular title is already in the table, there are no duplicate rows inserted
It ignores errors in the SQL syntax for the statement
It updates the created_at value if the title already exists in the table
It ignores any foreign key constraint errors
For the following Python code to work, what must be added to the title column in the CREATE TABLE statement for the Course table:
A NOT NULL constraint
An AUTOINCREMENT indication
A UNIQUE constraint
A PRIMARY KEY indication