Term
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Definition
| Consists of the table name and the column names |
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Term
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Definition
| Shows the rows of the tables |
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Term
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Definition
| Two dimensional arrangement of data; consists of a heading defining the table name and column names and a body containing rows of data |
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Term
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Definition
| Defines a set of values and permissible operations on the values; each column of a table is associated with this |
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Term
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Definition
| Connection between rows in two tables; shown by column values in one table that match column values in another table |
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Term
| Table-Oriented Terminology |
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Definition
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Term
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Definition
| Appeals to academic researchers |
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Term
| Record-Oriented Terminology |
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Definition
| Appeals to information systems professionals |
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Term
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Definition
| Each table must have a column or combination of columns with unique values; no row can contain a null value for any column of a primary key |
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Term
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Definition
| Column values in one table must match column values in a related table; only two kinds of values can be stored in a foreign key; a value matching a candidate key value in some row of the table containing the associated candidate key or a null value |
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Term
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Definition
| Column or combination of columns containing unique values for each row. The combination of every column in a table is always one of these because rows in a table must be unique. |
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Term
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Definition
| Minimal superkey; a superkey is minimal if removing any column makes it no longer unique |
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Term
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Definition
| A special value that represents the absence of an actual value; can mean that the actual value is unknown for does not apply to the given row |
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Term
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Definition
| Specially designated candidate key; cannot contain null values |
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Term
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Definition
| Column or combination of columns in which the values must match those of a candidate key; must have the same data type as its associated candidate key; in the CREATE TABLE statement of SQL, this must be associated with a primary key rather than merely a candidate key |
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Term
| Composite/Combined Primary Key |
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Definition
| Primary key consisting of more than one column |
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Term
| Self Referencing Relationship |
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Definition
| Relationship in which a foreign key refers to the same table; represent associations among members of the same set |
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