20 lines
291 B
Markdown
20 lines
291 B
Markdown
---
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title: SQL Join
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---
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```
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SELECT * FROM order_items LEFT OUTER JOIN orders ON order_items.order_id = orders.id
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```
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```
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__ __
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/ /\ \
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| A |u |B |
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\___\/__ /
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```
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* inner join = `u`
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* left outer join = `A` + `u`
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* right outer join = `u` + `B`
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* full outer join = `A` + `u` + `B`
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