40 lines
556 B
Markdown
40 lines
556 B
Markdown
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---
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tags:
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- SQL
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- databases
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---
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# Aggregate functions in SQL
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Aggregate functions enable us to return data about the data that a table holds.
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For example the sum of a given column or its average.
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## Count return with custom variable
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```sql
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SELECT COUNT(*) AS total_sales
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FROM SALES
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```
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## Sum
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```sql
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SELECT SUM(price) as total_value
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FROM sales
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```
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## Average
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```sql
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SELECT AVG(price) as average_income
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FROM sales
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```
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## Applying aggregate function with sorting applied
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```sql
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SELECT COUNT(*) AS total_sales
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FROM sales
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GROUP BY employee_id
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```
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