Hey my friends, a new post about this war. I don't know which is better, but I'll try to figure it out. I hope y'all enjoy this series. Here we go!
This time I'm going to talk about a few queries that can help you!
Count
If you need to count how many registers exist with the same query.
Mysql
SELECT count(*) FROM crews WHERE captain = 'Luffy';
MongoDB
db.crews.find({"captain":"Luffy"}).count()
Sum
If you need to sum a specific field.
Mysql
SELECT SUM(members) FROM crews;
MongoDB
db.crews.aggregate(
{
$match:{}
},
{
$group: {
_id: null,
sum: {
$sum: "$members"
}
}
});
Min
If you need to get the min field of a query.
Mysql
SELECT MIN(members) FROM crews;
MongoDB
db.crews.aggregate(
{
$match:{}
},
{
$group: {
_id: null,
min: {
$min: "$members"
}
}
});
Max
If you need to get the max field of a query.
Mysql
SELECT MAX(members) FROM crews;
MongoDB
db.crews.aggregate(
{
$match:{}
},
{
$group: {
_id: null,
max: {
$max: "$members"
}
}
});
Conclusion
- Structure: Mysql is easier than MongoDB.
Would you like to learn about other things?
I hope you enjoy my post and remember that I am just a Dev like you!