db.js

var mongoose = require( 'mongoose' );
var Schema   = mongoose.Schema;

var Block = new Schema(
{
    "number": {type: Number, index: {unique: true}},
    "hash": String,
    "parentHash": String,
    "nonce": String,
    "sha3Uncles": String,
    "logsBloom": String,
    "transactionsRoot": String,
    "stateRoot": String,
    "receiptRoot": String,
    "miner": {type: String, lowercase: true},
    "difficulty": String,
    "totalDifficulty": String,
    "size": Number,
    "extraData": String,
    "gasLimit": Number,
    "gasUsed": Number,
    "timestamp": Number,
    "blockTime": Number,
    "uncles": [String]
}, {collection: "Block"});

var Account = new Schema(
{
    "address": {type: String, index: {unique: true}},
    "balance": Number,
    "blockNumber": Number,
    "type": {type: Number, default: 0} // address: 0x0, contract: 0x1
}, {collection: "Account"});

var Contract = new Schema(
{
    "address": {type: String, index: {unique: true}},
    "blockNumber": Number,
    "ERC": {type: Number, index: true}, //0:normal contract, 2:ERC20, 3:ERC223
    "creationTransaction": String,
    "contractName": String,
    "tokenName": String,
    "symbol": String,
    "owner": String,
    "decimals": Number,
    "totalSupply": Number,
    "compilerVersion": String,
    "optimization": Boolean,
    "sourceCode": String,
    "abi": String,
    "byteCode": String
}, {collection: "Contract"});

var Transaction = new Schema(
{
    "hash": {type: String, index: {unique: true}, lowercase: true},
    "nonce": Number,
    "blockHash": String,
    "blockNumber": Number,
    "transactionIndex": Number,
    "status": Number,
    "from": {type: String, lowercase: true},
    "to": {type: String, lowercase: true},
    "creates": {type: String, lowercase: true},
    "value": String,
    "gas": Number,
    "gasUsed": Number,
    "gasPrice": String,
    "timestamp": Number,
    "input": String
}, {collection: "Transaction"});

var TokenTransfer = new Schema(
{
    "hash": {type: String, index: {unique: true}, lowercase: true},
    "blockNumber": Number,
    "method": String,
    "from": {type: String, lowercase: true},
    "to": {type: String, lowercase: true},
    "contract": {type: String, lowercase: true},
    "value": String,
    "timestamp": Number
}, {collection: "TokenTransfer"});

var BlockStat = new Schema(
{
    "number": {type: Number, index: {unique: true}},
    "timestamp": Number,
    "difficulty": String,
    "hashrate": String,
    "txCount": Number,
    "gasUsed": Number,
    "gasLimit": Number,
    "miner": String,
    "blockTime": Number,
    "uncleCount": Number
}, {collection: "BlockStat"});

var Market = new Schema(
{
    "symbol": String,
    "timestamp": Number,
    "quoteBTC": Number,
    "quoteUSD": Number
}, {collection: "Market"});

// create indices
Transaction.index({blockNumber:-1});
Transaction.index({from:1, blockNumber:-1});
Transaction.index({to:1, blockNumber:-1});
Transaction.index({creates:1, blockNumber:-1});
Account.index({balance:-1});
Account.index({balance:-1, blockNumber:-1});
Account.index({type:-1, balance:-1});
Block.index({miner:1});
Block.index({miner:1, blockNumber:-1});
Block.index({hash:1, number:-1});
Market.index({timestamp: -1});
TokenTransfer.index({blockNumber:-1});
TokenTransfer.index({from:1, blockNumber:-1});
TokenTransfer.index({to:1, blockNumber:-1});
TokenTransfer.index({contract:1, blockNumber:-1});

mongoose.model('BlockStat', BlockStat);
mongoose.model('Block', Block);
mongoose.model('Account', Account);
mongoose.model('Contract', Contract);
mongoose.model('Transaction', Transaction);
mongoose.model('Market', Market);
mongoose.model('TokenTransfer', TokenTransfer);
module.exports.BlockStat = mongoose.model('BlockStat');
module.exports.Block = mongoose.model('Block');
module.exports.Contract = mongoose.model('Contract');
module.exports.Transaction = mongoose.model('Transaction');
module.exports.Account = mongoose.model('Account');
module.exports.Market = mongoose.model('Market');
module.exports.TokenTransfer = mongoose.model('TokenTransfer');

mongoose.Promise = global.Promise;
mongoose.connect(process.env.MONGO_URI || 'mongodb://localhost/explorerDB', {
  useMongoClient: true
  // poolSize: 5,
  // rs_name: 'myReplicaSetName',
  // user: 'explorer',
  // pass: 'yourdbpasscode'
});

// mongoose.set('debug', true);