when there is a primary key foreign key relationship, what type of constraint becomes important? Input...
when there is a primary key foreign key relationship, what type of constraint becomes important?
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Validation
Entity Integrity
Referential Integrity
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when there is a primary key foreign key relationship, what type
of constraint becomes important?
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What is a foreign key and a primary key and how do they relate to each...
What is a foreign key and a primary key and how do they relate to each other? Why are foreign keys and the referential rule important in representing relationships within a database? Why does declaring a primary key represent a constraint on the values possible in a relation
QUESTION 1 What is the most common relationship within a relational database? Select the best answer...
QUESTION 1 What is the most common relationship within a relational database? Select the best answer from the following. One-To-One relationship. o One-To-Many relationship. Many-To-Many relationship. Zero-To-Zero relationship. QUESTION 2 What is an "entity'? Select the best answer from the following. An entity, for our purposes, is the same as a table in the database. An entity represents one of the columns in an individual table. There are no entities in a relational database. Entities are only part of NoSQL...
True or False questions: 1. A data type mismatch error would occur when the primary key...
True or False questions: 1. A data type mismatch error would occur when the primary key data data type is auto number and the foreign key in the related table is number. 2. The data type long integer is the same as integer. 3. When using SQL, the SELECT clause isolates tables in the database. 4. A Referential Integrity violation occur when the primary key is null. 5. When an REA model has 7 entities ,2 linking tables, 3 Resource...
QUESTION 6 Which of the following statements best illustrates the "Key" constraint? The schema MUST be...
QUESTION 6 Which of the following statements best illustrates the "Key" constraint? The schema MUST be created before tables are added A primary key MUST NOT have duplicate values A foreign key value MUST have a value already present as a primary key in another table (or be NULL) A primary key value MUST have a value QUESTION 7 Which of the following statements best illustrates the "Referential Integrity" constraint? The schema MUST be created before tables are added A...
The primary key for M:N relationship tables O is a single attribute. @ always consists of...
The primary key for M:N relationship tables O is a single attribute. @ always consists of two attributes. O is the primary key of the most important entity linked to that relationship does not exist. Many-to-many relationship tables only use foreign keys
1- Explain, as best you can, why the primary key of the "one" side becomes the...
1- Explain, as best you can, why the primary key of the "one" side becomes the foreign key on the "many" side in a 1:M relationship?
when you establish a relationship between a primary and foriegn key, the dbms can enforce integrity...
when you establish a relationship between a primary and foriegn key, the dbms can enforce integrity constraints? true or false what database key links one table to another? what data base function allows you to define the data your database is storing?
List the characteristics that a table must have to be considered a relation. List two synonyms...
List the characteristics that a table must have to be considered a relation. List two synonyms for “file,” two for “record,” and two for “field.” What are the four uses of a primary key? What are the desirable characteristics of a primary key? What is a surrogate key and when do you use them? What is a foreign key? What is referential integrity and why is it important? What are the three possible interpretations of a null value? What is...
When we translate a 1:N relationship in an ERD to a relational schema, we add the...
When we translate a 1:N relationship in an ERD to a relational schema, we add the primary key of one-side entity to the many-side entity as a foreign key. Why should we do so? What if we add the PK of N-side entity to one-side entity?
When you have a one-to-many relationship, which of the following is correct? one-to-many relationships are not...
When you have a one-to-many relationship, which of the following is correct? one-to-many relationships are not allowed, only one-to-one relationships are allowed The primary key on the many side becomes a foreign key on the one side The primary key on the one side becomes a foreign key on the many side All of the above None of the above
QUESTION 1 What is the most common relationship within a relational database? Select the best answer from the following. One-To-One relationship. o One-To-Many relationship. Many-To-Many relationship. Zero-To-Zero relationship. QUESTION 2 What is an "entity'? Select the best answer from the following. An entity, for our purposes, is the same as a table in the database. An entity represents one of the columns in an individual table. There are no entities in a relational database. Entities are only part of NoSQL...
QUESTION 6 Which of the following statements best illustrates the "Key" constraint? The schema MUST be created before tables are added A primary key MUST NOT have duplicate values A foreign key value MUST have a value already present as a primary key in another table (or be NULL) A primary key value MUST have a value QUESTION 7 Which of the following statements best illustrates the "Referential Integrity" constraint? The schema MUST be created before tables are added A...
The primary key for M:N relationship tables O is a single attribute. @ always consists of two attributes. O is the primary key of the most important entity linked to that relationship does not exist. Many-to-many relationship tables only use foreign keys
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