May 10, 2019 · 111-56-4490 WILLIAMS SEATTLE WA ACCT JR 3.40 Which table below is union compatible with the Student_1 and Student_2 tables? Student_3(StudentID (varchar(9), FirstName, LastName, State, Major, ... Course Hero is not …
Aug 25, 2017 · Selected Answer: Student_3 (StdSSN (varchar (9), StdLastName, StdCity, StdState, StdGPA) This is union compatible with Student_1 and Student_2: Student_3 (stdSSN (varchar (9),StdLastName, StdCity,StdState,StdGPA) Two relations R and S , are said to be UNION COMPATIBLE, only if they satisfy these two conditions:
Answer: None of the above. Explanation: Option1 has two columns FirstName, LastName which is not present in Student_1 and Student_2. So, not option1. Option2 StudentID is of type integer but the values of StudentId in both tables include (-) hyphen which is of type varchar. So, not this option. Option3 StudentID has varchar(9) but the size should be 11 when we compare both …
To query data you would join the tables on the keys: select * from student s join enrollment e on s.student_id = e.student_id join class c on c.class_id = e.class_id. If you want to learn more about this, search for database normalization and normal forms in the context of relational databases. And here's a small demo.
A subquery is normally expressed inside parenthesis and can return zero, one, or more rows and each row can have one or more columns. What are the three types of results a subquery can return.
By definition, a candidate key is one that can be used to identify all of the remaining attributes, but it was not chosen to be a PK for some reason. In other words, a candidate key can serve as a primary key, but it was not chosen for that task for one reason or another.
A transitive dependency is a dependency of one non prime attribute on another non prime attribute. (The problem with transitive dependencies is that they still yield data anomalies.) Suppose that someone tells you that an attribute that is part of a composite primary key is also a candidate key.
What is a subquery, and what are its basic characteristics. A subquery is a query (expressed as a SELECT statement) that is located inside another query. The first SQL statement is known as the outer query, the second is known as the inner query or subquery. The inner query or subquery is normally executed first.
The first SQL statement is known as the outer query, the second is known as the inner query or subquery. The inner query or subquery is normally executed first. The output of the inner query is used as the input for the outer query.
The output of the inner query is used as the input for the outer query. A subquery is normally expressed inside parenthesis and can return zero, one, or more rows and each row can have one or more columns. What are the three types of results a subquery can return.
What is normalization. a process that assigns attributes to entities so that data redundancies are reduced or eliminated. When is a table in 1NF. when it is in table format with no repeating groups. When is a table in 2NF. when it is in 1NF and has no partial dependencies.
In a pair of tables to be joined, a join that yields all the rows in the left table, including those that have no matching values in the other table. right outer join. In a pair of tables to be joined, a join that yields all of the rows in the right table, including the ones with no matching values in the other table.
Discuss the difference between a composite key and a composite attribute. A composite key is one that consists of more than one attribute. A composite attribute is one that can be subdivided to yield meaningful attributes for each of its components. predicate logic.
SQL includes commands to insert, update, delete, and retrieve data within the database tables. schema. A logical grouping of database objects, such as tables, indexes, views, and queries, that are related to each other. Usually, a schema belongs to a single user or application.
SQL includes commands to create database objects such as tables, indexes, and views, as well as commands to define access rights to those database objects. data manipulation language (DML) SQL includes commands to insert, update, delete, and retrieve data within the database tables. schema.
Entity integrity is the condition in which each row (entity instance) in the table has its own unique identity. To ensure entity integrity, the primary key has two requirements: (1) all of the values in the primary key must be unique, and (2) no key attribute in the primary key can contain a null.