I have an input field of type="number" and I want the user to only be able to input either number 3, or number 5 or number 10. Any other number is not allowed. How can I do this, using only…
I have two tables, from which I need to select the latest purchase of each customer from the US. The query must present the user_id and the purchased item columns: (I left out some of the records from both tables)…
I want to find the time and temp in the row with maximum temp value in a 2d array. Here is sample data for my weather array: [ ['time' => '00:00', 'temp' => '15.1'], ['time' => '00:00', 'temp' => '15.1'],…
I have a MySQL database with lots of entrys with columns like "local_time", "temp", "wind", etc. What I want to archive is get in just one query the MIN value for temp, the MAX value for temp in each day…
In SQL, how can I select the minimum value of a column a (integer) where the column b (integer) is the maximum value for that column, using only one select ? SELECT MIN(a) OVER (PARTITION BY MAX(b)) as res #seems…
I have a mysql table with the following columns- Date, country, YEAR, MONTH, supercategory, class, corp_manufacturer, brand, license,item_description,amount, units, arp. Total number of records = 7.1 million Now i want to add a new column which shows the max value…
Consider a set of points in an n-dimensional space. Each dimension is bounded in the range [0, 1] inclusive. Add a new point to the space as far away as possible from its nearest neighbor. Where should that point go?…
I have a table with different people that got different grades. I need to find the two persons with the highest grades. And if there is any ties, select them aswell. The only thing ive got right now is the…
PHP version 7.0 mySql version 5.5 I'm trying to perform an UPDATE on an existing record. I search for the max(DateTime) to get the last record. DateTime is the key field and is of the type DateTime. There is one…