MongoDB Indexing and Agregation.txt

show dbs
use customer
db.cust_table.insert({Item_id:1,Cust_Name:"Ram",Product:"Milk",Amount:40});
db.cust_table.insert({Item_id:2,Cust_Name:"Ram",Product:"Parle_G",Amount:50});
db.cust_table.insert({Item_id:3,Cust_Name:"Mohan",Product:"Lays Chips",Amount:40});
db.cust_table.insert({Item_id:4,Cust_Name:"Shivam",Product:"Mentos",Amount:10});
db.cust_table.insert({Item_id:5,Cust_Name:"Mohan",Product:"Maggie",Amount:60});
db.cust_table.aggregate({$group:{_id:"$Cust_Name","total":{$sum:"$Amount"}}});
db.cust_table.aggregate({$group:{_id:"$Cust_Name","total":{$avg:"$Amount"}}});
db.cust_table.aggregate({$group:{_id:"$Cust_Name","total":{$min:"$Amount"}}});
db.cust_table.aggregate({$group:{_id:"$Cust_Name","total":{$max:"$Amount"}}});
db.cust_table.aggregate({$group:{_id:"$Cust_Name","total":{$first:"$Amount"}}});
db.cust_table.aggregate({$group:{_id:"$Cust_Name","total":{$last:"$Amount"}}});
db.cust_table.aggregate({$group:{_id:"$Cust_Name","total":{$psuh:"$Amount"}}});
db.cust_table.aggregate({$group:{_id:"$Cust_Name","total":{$sum:1}}});
db.cust_table.aggregate({$group:{_id:"$Cust_Name","total":{$addToSet:"$Amount"}}});
db.cust_table.createIndex({'Item_id':1})
db.cust_table.createIndex({'Item_id':2})
db.cust_table.createIndex({'Item_id':4})
db.cust_table.getIndexes()
db.cust_table.dropIndex({'Item_id':4})
db.cust_table.dropIndex({'Item_id':1})
db.cust_table.getIndexes()
db.cust_table.getIndexes()