Execute a SQL statement to add a unique constraint for the order_id in order_db

Trying to write SQL statements for these shown here and having issues with them working. Explanation on this would be appreciated.

Execute a SQL statement to add a check constraint to the field mode_of_payment with values ('D', 'R' or 'C") in order_db

order db orderid int custid int itemcode int orderquantity int deliverydate date modeofpayment char(1) date_of_order date

SQL A table Products have: a name (TEXT) a description (TEXT) a unit cost stored in cents (INTEGER) and of course we also add an id column to identify them. Separately, we'd like to track the number of items in stock for each product. To do so we'll have a store and an inventory table. Stores have just an id and a name. Then, our inventory table should combine stores and products, listing how much of each product each store has in stock. a product_id (INTEGER) a store_id (INTEGER) a quantity (INTEGER) in stock Now we can insert some stores, products and inventory into our database. There are 2 stores -- one called NY and one called NJ. There are 2 products we are concerned with. Their names are sneakers, costing $220 (remember this is dollars!) and boots costing $350. Use any description for each that you'd like. NY has 4 sneakers in stock and 3 boots. NJ has 5 sneakers in stock and no boots. Insert the above data into the tables you have created.

INFO 2303  Database Programming Assignment  : PL/SQL Practice   Note: PL/SQL can be executed in SQL*Plus or SQL Developer or Oracle Live SQL.   Write an anonymous PL/SQL block that will delete all patients for doctors that works in the Family Practice Verify that patients have been deleted accordingly. Then do a select * from patients where doc_id = (select doc_id from doctor where area = ‘Family Practice’. You should get no rows.

Database Systems please help me answer this question I will give you a good rating Thank you!

Need help writing SQL queries for sample data base

In what situations might the SOUNDEX function be useful in SQL when querying text data?

True or False below: Given two relations named A and B, if we q-JOIN A and B, the maximum number of attributes in the result relation could be (the number of attributes of A) times(*) the number of attributes of B).  * in an SQL SELECT statement means “all the tuples”.   In relational algebra, Cartesian Product (X) can be implemented using the q-JOIN operator.  Cartesian Product ISA q-JOIN where q-condition always evaluates to true. SQL is based on Predicate Calculus. A query in SQL always specifies what should be included in the query result.