Mysql gets a method for group by total record rows _mysql

This article describes the MySQL to get group by total record row number of methods, share for everyone for reference. The specific methods are analyzed as follows:

In general, MySQL gets the total number of records grouped by the group by internally that can get to a field, and cannot count the number of records grouped.

In MySQL, you can use Sql_calc_found_rows to get the number of rows in a query, which is written in many paging programs:

Copy Code code as follows:

SELECT COUNT (*) from ' table ' WHERE ...;

Identify the total number of eligible records:

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SELECT * from ' table ' WHERE ... limit m,n;

Query the data to be displayed by the page such that a statement can be changed to:

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SELECT sql_calc_found_rows * from ' table ' WHERE ... limit M, N;
SELECT found_rows ();

So the Sql_calc_found_rows and found_rows () functions that can be combined with MySQL can be implemented:

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SELECT sql_calc_found_rows t3.id, a,bunch,of,other,stuff from T1, T2, T3 where (associate, T1,t2,and, and each other) T3 Upby t3.id LIMIT 10,20select found_rows () as Count;

Use the above two statements to complete the total number of record rows that meet group by.

Add:

Simple use of GROUP by:

Copy Code code as follows:

' SELECT column_id,count (*) as Count from My_table Group by column_id ';

I hope this article is helpful to the design of MySQL database.