Term
| Outer Join(LEFTJOIN) does what function? |
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Definition
| An outer join will combine rows from different tables even if the join condition is not met. |
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Term
| Outer Join(LEFTJOIN) Syntax: |
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Definition
SELECT column_name(s)
FROM table1
LEFT JOIN table2
ON table1.column_name = table2.column_name; |
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Term
| What is the function of the WITH clause? |
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Definition
The WITH clause stores the result of a query in a temporary table (temporary_movies) using an alias.
Multiple temporary tables can be defined with one instance of the WITH keyword. |
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Term
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Definition
WITH temporary_movies AS (
SELECT *
FROM movies
)
SELECT *
FROM temporary_movies
WHERE year BETWEEN 2000 AND 2020; |
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Term
| UNION clause does what function? |
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Definition
| The UNION clause is used to combine results that appear from multiple SELECT statements and filter duplicates. |
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Term
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Definition
SELECT name
FROM first_names
UNION
SELECT name
FROM last_names |
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Term
| CROSS JOIN does what function? |
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Definition
| The CROSS JOIN clause is used to combine each row from one table with each row from another in the result set. This JOIN is helpful for creating all possible combinations for the records (rows) in two tables. |
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Term
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Definition
SELECT shirts.shirt_color,
pants.pants_color
FROM shirts
CROSS JOIN pants; |
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Term
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Definition
| A foreign key is a reference in one table’s records to the primary key of another table. |
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Term
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Definition
| A primary key column in a SQL table is used to uniquely identify each record in that table. A primary key cannot be NULL. |
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Term
| What is an Inner JOIN used for? |
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Definition
The JOIN clause allows for the return of results from more than one table by joining them together with other results based on common column values specified using an ON clause.
It will only return results matching the condition specified by ON. |
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