Here are six top SQL aggregate functions rules. Aggregate functions, you can also call column functions. Because you can use these functions only for Table columns.
6 SQL Aggregate Functions Rules
Example Function
The syntax.
AVG(SALARY) - Here SALARY is name of the column. Below is the list of rules.
#1 Rule
- A select query that uses Aggregate function called summary query.
#2 Rule
- The result of AVG and SUM functions is numeric. These functions only work with numerics.
#3 Rule
- The result of MIN, MAX and COUNT can be a numeric or DATE, or String value.
#4 Rule
- By default DUPLICATEs are considered. So use distinct to ignore duplicates.
#5 Rule
- You cannot mix aggregate and non-aggregate functions in SELECT statement. You need GROUP BY to mix both.
#6 Rule
- Aggregate functions ignore NULL values.
QUIZ
Try the tricky questions.
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