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What are the various reasons that lead to the occurrence of NULL values in relations?
Wiki User
∙ 7y ago
A given field in a database table might be for a values that, in certain case, no such values exist or can be determined. For example, in an employee database, a field might be a foreign key to that employee's direct manager. However, in the case of the CEO, there is no such person. In that case, the field would be set to Null.
Wiki User
∙ 7y ago
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Characteristics of relations in relational database model?
No Duplicate Tuples - A relation cannot contain two or more tuples which have the same values for all the attributes. i.e., In any relation, every row is unique. • Tuples are unordered - The order of rows in a relation is immaterial. • Attributes are unordered - The order of columns in a relation is immaterial. • Attribute Values are Atomic - Each tuple contains exactly one value for each attribute. It may be noted that many of the properties of relations follow the fact that the body of a relation is a mathematical set.
What is the purpose of using Data Tables?
In Excel it allows you to do analysis based on a formula having one or two values changed to produce a table of various results. It will take values from the first row and first column and use them in a formula. The initial formula is in the cell on the first row and first column, in other words the top left cell of the table. Whatever the formula does, it then uses the values to fill the table. So say you put a formula in the top corner cell which adds two cells. Then you would use the first value on each row and column of the table as values for the formula.In Excel it allows you to do analysis based on a formula having one or two values changed to produce a table of various results. It will take values from the first row and first column and use them in a formula. The initial formula is in the cell on the first row and first column, in other words the top left cell of the table. Whatever the formula does, it then uses the values to fill the table. So say you put a formula in the top corner cell which adds two cells. Then you would use the first value on each row and column of the table as values for the formula.In Excel it allows you to do analysis based on a formula having one or two values changed to produce a table of various results. It will take values from the first row and first column and use them in a formula. The initial formula is in the cell on the first row and first column, in other words the top left cell of the table. Whatever the formula does, it then uses the values to fill the table. So say you put a formula in the top corner cell which adds two cells. Then you would use the first value on each row and column of the table as values for the formula.In Excel it allows you to do analysis based on a formula having one or two values changed to produce a table of various results. It will take values from the first row and first column and use them in a formula. The initial formula is in the cell on the first row and first column, in other words the top left cell of the table. Whatever the formula does, it then uses the values to fill the table. So say you put a formula in the top corner cell which adds two cells. Then you would use the first value on each row and column of the table as values for the formula.In Excel it allows you to do analysis based on a formula having one or two values changed to produce a table of various results. It will take values from the first row and first column and use them in a formula. The initial formula is in the cell on the first row and first column, in other words the top left cell of the table. Whatever the formula does, it then uses the values to fill the table. So say you put a formula in the top corner cell which adds two cells. Then you would use the first value on each row and column of the table as values for the formula.In Excel it allows you to do analysis based on a formula having one or two values changed to produce a table of various results. It will take values from the first row and first column and use them in a formula. The initial formula is in the cell on the first row and first column, in other words the top left cell of the table. Whatever the formula does, it then uses the values to fill the table. So say you put a formula in the top corner cell which adds two cells. Then you would use the first value on each row and column of the table as values for the formula.In Excel it allows you to do analysis based on a formula having one or two values changed to produce a table of various results. It will take values from the first row and first column and use them in a formula. The initial formula is in the cell on the first row and first column, in other words the top left cell of the table. Whatever the formula does, it then uses the values to fill the table. So say you put a formula in the top corner cell which adds two cells. Then you would use the first value on each row and column of the table as values for the formula.In Excel it allows you to do analysis based on a formula having one or two values changed to produce a table of various results. It will take values from the first row and first column and use them in a formula. The initial formula is in the cell on the first row and first column, in other words the top left cell of the table. Whatever the formula does, it then uses the values to fill the table. So say you put a formula in the top corner cell which adds two cells. Then you would use the first value on each row and column of the table as values for the formula.In Excel it allows you to do analysis based on a formula having one or two values changed to produce a table of various results. It will take values from the first row and first column and use them in a formula. The initial formula is in the cell on the first row and first column, in other words the top left cell of the table. Whatever the formula does, it then uses the values to fill the table. So say you put a formula in the top corner cell which adds two cells. Then you would use the first value on each row and column of the table as values for the formula.In Excel it allows you to do analysis based on a formula having one or two values changed to produce a table of various results. It will take values from the first row and first column and use them in a formula. The initial formula is in the cell on the first row and first column, in other words the top left cell of the table. Whatever the formula does, it then uses the values to fill the table. So say you put a formula in the top corner cell which adds two cells. Then you would use the first value on each row and column of the table as values for the formula.In Excel it allows you to do analysis based on a formula having one or two values changed to produce a table of various results. It will take values from the first row and first column and use them in a formula. The initial formula is in the cell on the first row and first column, in other words the top left cell of the table. Whatever the formula does, it then uses the values to fill the table. So say you put a formula in the top corner cell which adds two cells. Then you would use the first value on each row and column of the table as values for the formula.
List two reasons why null values might be introducedin database?
1. special requirements for its use in SQL joins. 2. special handling required by aggregate functions and SQL grouping operators
What is the sum of values in a data set divided by the number of values?
It is the mean or average value of the n values. [Σn xi]/n = xmean
Which interval contains the fewest data values?
Which contains the fewest data values
Discuss the various reasons that lead to the occurrence of null values in relations?
If an instance (tuple) of a relation lacks having that attribute. i.e: a student that does not have a mobile phone or an office phones. The values for these attribute for that particular student will be null. It is important to note that a null value can mean either an unknown value, or a value that exists, but not yet available.
What are the values and reasons of art?
values are the values and reason for arts
Why are values is important to the study of public relations?
yes! the values is important to the study of public relations because then ly we can know the consumer needz and satisfaction...!
WHAT IS Probability of occurrence of numbers ending with 9 Among values 1 to 100?
It is 1/10
Why do you use algebra?
We use algebra for many reasons and one of them is for replacing knowm values into unknown values
Who forms your values?
People form values from themselves, their family, friends, religion and various philosophies.
What are the reasons to spot untrustworthy emails?
people who decouple money from their values
Why do various food proteins have different nutritional value?
Why do various food proteins have different nutritional values?
In the short story an occurrence at owl creek bridge what saying does Peyton believe in his heart?
Peyton Farquhar values his wife, and kids most in life.
What is a short definition of algebra?
The branch of mathematics that deals with general statements of relations, utilizing letters and other symbols to represent specific sets of numbers, values, vectors, etc., in the description of such relations.
What is bundle in android?
A mapping from String values to various Parcelable types.
Explain the main concepts and values in industrial relations.?
Fairness and equity; power and authority; right and responsibility; and integrity and trust
