Term
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Definition
Computations of totals and subtotals...
examples: Sum, AVG, Min, Max, Count, StDev, StdDev, Var |
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Term
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Definition
| giving table a new name - useful when needing data from one table for two entities ( customer city and employee city both stored in city table) |
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Term
| What are the three basic tasks of a query language? |
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Definition
1. Define the Database
2. Change the data
3. Retrieve the data |
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Term
| What are the four questions used to create a query? |
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Definition
(1)SELECT - What output (columns and calculations) do you want to see?
(2)FROM - What do you know or what constraints are given?
(3)JOIN - What tables are involved?
(4)WHERE - How are the tables joined? What needs to be met? |
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Term
| What is the basic structure of the SQL SELECT command? |
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Definition
| SELECT columns or SELECT Table.Column |
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Term
| What is the purpose of the DISTINCT operator? |
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Definition
| Tells the DBMS to display only rows that are unique |
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Term
| Why is it important to use parentheses in complex (Boolean) WHERE clauses? |
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Definition
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Term
| How is pattern matching used to select rows of data? |
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Definition
| p. 191 it allows you to search for data that is matches a pattern using wildcards for all data before or for a singel |
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Term
| What is DeMorgan’s law, and how does it simplify conditions? |
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Definition
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Term
| How do you compute subtotals using SQL? |
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Definition
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Term
| How do the basic SQL arithmetic operators (+, -, etc.) differ from the aggregation (SUM, etc.) commands? |
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Definition
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Term
| What basic aggregation functions are available in the SELECT command? |
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Definition
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Term
| What is the difference between Count and Sum? Give an example of how each would be used. |
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Definition
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Term
| What is the difference between the WHERE and HAVING clauses? Give an example of how each would be used. |
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Definition
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Term
| What is the SQL syntax for joining two tables? |
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Definition
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Term
| How do you identify a column when the same name appears in more than one table? |
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Definition
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