Mysql contains several aggregate functions

MySQL provides a wealth of aggregate functions for data summary and statistics, including: COUNT(), SUM(), AVG(), MIN(), MAX(), GROUP_CONCAT(), etc. These functions can be used with the GROUP BY clause to perform aggregate calculations on specific groupings to extract meaningful insights.

Different aggregate functions included in MySQL

Aggregation functions are used to combine a set of values ​​into a single value , to summarize and make statistics on the data. There are various aggregate functions available in MySQL, each with its specific purpose.

Commonly used aggregate functions include:

• COUNT(): Counts the number of non-NULL values ​​in a set of rows.
• SUM(): Calculate the sum of a set of numeric fields.
• AVG(): Calculate the average of a set of numeric fields.
• MIN(): Returns the minimum value in a set of values.
• MAX(): Returns the maximum value in a set of values.
• GROUP_CONCAT(): Concatenate a set of values ​​into a string.

Other common aggregate functions:

• STDDEV(): Calculate the standard deviation of a set of numeric fields.
• VARIANCE(): Calculate the variance of a set of numeric fields.
• COVARIANCE(): Calculate the covariance of two sets of numeric fields.
• CORR(): Calculate the correlation coefficient between two sets of numeric fields.
• MEDIAN(): Calculate the median of a set of numeric fields.

When using aggregate functions, you need to use the GROUP BY clause to group the data so that the aggregate function can be calculated separately for each group. For example:

<code class="sql">SELECT department, SUM(salary)
FROM employee
GROUP BY department;</code>

This will return a result set showing the total salary of employees in each department.

Aggregation functions are very useful for analyzing and summarizing data. By using these functions, you can easily extract meaningful insights from large amounts of data.

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