Selecting Data between Dates in MySQL
In MySQL, you can retrieve data from a date range using the BETWEEN operator. For instance, to select data from January 1, 2009 to the current date from a table named 'events':
SELECT * FROM events WHERE datetime_column BETWEEN '2009-01-01' AND CURDATE();
This query will retrieve all rows where the datetime_column value falls between the specified dates.
Counting Data per Day from a Specified Date
To count the number of rows for each day from January 1, 2009 onwards, you can use the following query:
SELECT DATE(datetime_column), COUNT(*) AS num_rows FROM events WHERE datetime_column >= '2009-01-01' GROUP BY DATE(datetime_column);
This query uses the DATE() function to extract the date part from the datetime_column and groups the results by date. The COUNT() function is used to determine the number of rows for each day.
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