SQL + mysql random data reading-advanced issues such as a table class in which the data is a roster, such as name, age, gender, and nationality. now I want to get such a random result: A random record is listed for each province based on the nationality. all provinces in the roster need to read. how can I write this SQL statement? ------ Solution ------------------ selectm. * from (se SQL + mysql random data reading --- advanced problem
For example, there is a table class with data in a roster, such as name, age, gender, and nationality.
Now I want to get such a random result: each province randomly lists a record according to its place of origin. all the provinces in the roster will be read.
How can I write this SQL statement?
------ Solution --------------------
Select m. * from (select * from user order by rand () m group by m. area_id
User is your table name, and area_id is your place of origin
Solve the problem.
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