Php-html drop-down menu selection problem

phphtml data

Novice, temporarily arranged to write HTML, related to the screening problem, the first drop-down menu can pass my preset value, called Type bar, type has 123456 major categories, the second drop-down menu is based on the PHP link MySQL to check out a bunch of data, you need to select the first drop-down menu, The second drop-down menu is based on the first type to determine, and filter out the data should be displayed for the user's second choice, the last click on the Query button when the value of these two drop-down menu needs to pass value to the PHP backend, for help, thank you

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