I have a quick question I haven't been able to find an answer for in google searches. When performing addition and subtraction operations on a mysql table where I could have multiple users interacting with the database simultaneously, how does it handle those requests?
For example if I want to track how many email submissions have been completed using a php script to add 1 to a field like,
"UPDATE $table SET emailSubmits = (emailSubmits + 1)"
and I've already had 10 submissions and I get 2 people who submit their email at the same time, and they both pull the value of that field at the same time (10), will both instances try to update the quantity to 11 or is mySQL smart enough to manage simultaneous submissions so that I still end up with a total of 12?...Also if it is capable of this, does the same hold true if I have the possibility of 1,000 or 10,000 submissions simultaneously?
Mysql or like other relational Database lock the current row where they make an operation. Mysql will push the other request in pool and after the first make is operation the second will does their.