在byfn中启用couchDB很简单
./byfn.sh up -c mychannel -s couchdb
其中的过程了解一下：
1，加上-s couchdb参数以后，byfn脚本内的启动命令就变成了
docker-compose -f docker-compose-cli.yaml -f docker-compose-couch.yaml up -d
代表着docker-compose启动的时候，把docker-compose-couch.yaml也加载进去
2，docker-compose-couch.yaml中的配置，是给4个peer各启动一个couchdb的容器，因此脚本执行完之后应该有13个容器在运行，包含1个cli，1个order，3个chaincode，4个peer，4个couchdb
3，如果在不使用docker启动的情况下，修改peer节点的core.yaml文件中的ledger.state.stateDatabase属性，并配置好couchDBAddress以及用户名和密码(默认的用户名和密码都是空的)
下面部署新的链码，并建立索引：
使用的是fabric-samples\chaincode\marbles02\go目录下的链码，该链码存储的marble的数据结构是
type marble struct {
ObjectType string `json:"docType"` //docType is used to distinguish the various types of objects in state database
Name string `json:"name"` //the field tags are needed to keep case from bouncing around
Color string `json:"color"`
Size int `json:"size"`
Owner string `json:"owner"`
}
为其中的docType和owner字段新建一个名为indexOwner的索引的配置文件indexOwner.json如下
{"index":{"fields":["docType","owner"]},"ddoc":"indexOwnerDoc", "name":"indexOwner","type":"json"}
这个json文件必须保存在链码同级别目录下的META-INF\statedb\couchdb\indexes文件夹下，目录结构如图
因此，新建索引是无需对chaincode做额外开发的，只需要在部署的时候，将对应的索引配置文件放到对应的位置即可
进入cli容器
docker exec -it cli bash
部署链码：
peer chaincode install -n marbles -v 1.0 -p github.com/chaincode/marbles02/go
实力化
export CHANNEL_NAME=mychannel
peer chaincode instantiate -o orderer.example.com:7050 --tls --cafile /opt/gopath/src/github.com/hyperledger/fabric/peer/crypto/ordererOrganizations/example.com/orderers/orderer.example.com/msp/tlscacerts/tlsca.example.com-cert.pem -C $CHANNEL_NAME -n marbles -v 1.0 -c '{"Args":["init"]}' -P "OR ('Org0MSP.peer','Org1MSP.peer')"
打开一个新的终端窗口，然后运行下边的命令来验证索引是否被正确创建
docker logs peer0.org1.example.com 2>&1 | grep "CouchDB index"
输出
CreateIndex -> INFO 088 Created CouchDB index [indexOwner] in state database [mychannel_marbles] using design document [_design/indexOwnerDoc]
代表索引创建成功
存入一条数据
peer chaincode invoke -o orderer.example.com:7050 --tls --cafile /opt/gopath/src/github.com/hyperledger/fabric/peer/crypto/ordererOrganizations/example.com/orderers/orderer.example.com/msp/tlscacerts/tlsca.example.com-cert.pem -C $CHANNEL_NAME -n marbles -c '{"Args":["initMarble","marble1","blue","35","tom"]}'
使用索引进行查询：
peer chaincode query -C $CHANNEL_NAME -n marbles -c '{"Args":["queryMarbles", "{\"selector\":{\"docType\":\"marble\",\"owner\":\"tom\"}, \"use_index\":[\"_design/indexOwnerDoc\", \"indexOwner\"]}"]}'
数据量很少，所以查询速度并不明显，需要关注的是查询参数：
queryMarbles是链码中定义的函数名
{"selector":{"docType":"marble","owner":"tom"}是一个“ad hoc 选择器”，用来查找所有 owner 属性值为 tom 的 marble 记录
"use_index":["_design/indexOwnerDoc", "indexOwner"]指定设计文档名 indexOwnerDoc 和索引名 indexOwner
使用分页：
再新增一些数据
peer chaincode invoke -o orderer.example.com:7050 --tls --cafile /opt/gopath/src/github.com/hyperledger/fabric/peer/crypto/ordererOrganizations/example.com/orderers/orderer.example.com/msp/tlscacerts/tlsca.example.com-cert.pem -C $CHANNEL_NAME -n marbles -c '{"Args":["initMarble","marble2","yellow","35","tom"]}'
peer chaincode invoke -o orderer.example.com:7050 --tls --cafile /opt/gopath/src/github.com/hyperledger/fabric/peer/crypto/ordererOrganizations/example.com/orderers/orderer.example.com/msp/tlscacerts/tlsca.example.com-cert.pem -C $CHANNEL_NAME -n marbles -c '{"Args":["initMarble","marble3","green","20","tom"]}'
peer chaincode invoke -o orderer.example.com:7050 --tls --cafile /opt/gopath/src/github.com/hyperledger/fabric/peer/crypto/ordererOrganizations/example.com/orderers/orderer.example.com/msp/tlscacerts/tlsca.example.com-cert.pem -C $CHANNEL_NAME -n marbles -c '{"Args":["initMarble","marble4","purple","20","tom"]}'
peer chaincode invoke -o orderer.example.com:7050 --tls --cafile /opt/gopath/src/github.com/hyperledger/fabric/peer/crypto/ordererOrganizations/example.com/orderers/orderer.example.com/msp/tlscacerts/tlsca.example.com-cert.pem -C $CHANNEL_NAME -n marbles -c '{"Args":["initMarble","marble5","blue","40","tom"]}'
调用链码中的queryMarblesWithPagination 方法
peer chaincode query -C $CHANNEL_NAME -n marbles -c '{"Args":["queryMarblesWithPagination", "{\"selector\":{\"docType\":\"marble\",\"owner\":\"tom\"}, \"use_index\":[\"_design/indexOwnerDoc\", \"indexOwner\"]}","3",""]}'
3表示每页显示3条数据，后面空的参数是bookmark，用来定义从哪个数据开始，返回值如下
[{"Key":"marble1", "Record":{"color":"blue","docType":"marble","name":"marble1","owner":"tom","size":35}},
[{"Key":"marble2", "Record":{"color":"yellow","docType":"marble","name":"marble2","owner":"tom","size":35}},
[{"Key":"marble3", "Record":{"color":"green","docType":"marble","name":"marble3","owner":"tom","size":20}}]
[[{"ResponseMetadata":{"RecordsCount":"3", "Bookmark":"g1AAAABLeJzLYWBgYMpgSmHgKy5JLCrJTq2MT8lPzkzJBYqz5yYWJeWkGoOkOWDSOSANIFk2iCyIyVySn5uVBQAGEhRz"}}]
返回值当中包含了一个bookmark，可以用于下次查询时传入的参数
peer chaincode query -C $CHANNEL_NAME -n marbles -c '{"Args":["queryMarblesWithPagination", "{\"selector\":{\"docType\":\"marble\",\"owner\":\"tom\"}, \"use_index\":[\"_design/indexOwnerDoc\", \"indexOwner\"]}","3","g1AAAABLeJzLYWBgYMpgSmHgKy5JLCrJTq2MT8lPzkzJBYqz5yYWJeWkGoOkOWDSOSANIFk2iCyIyVySn5uVBQAGEhRz"]}'
返回2条数据：
[{"Key":"marble4", "Record":{"color":"purple","docType":"marble","name":"marble4","owner":"tom","size":20}},
{"Key":"marble5", "Record":{"color":"blue","docType":"marble","name":"marble5","owner":"tom","size":40}}]
[[{"ResponseMetadata":{"RecordsCount":"2", "Bookmark":"g1AAAABLeJzLYWBgYMpgSmHgKy5JLCrJTq2MT8lPzkzJBYqz5yYWJeWkmoKkOWDSOSANIFk2iCyIyVySn5uVBQAGYhR1"}}]
升级和删除索引都不在fabric功能内
升级索引：
curl -i -X POST -H "Content-Type: application/json" -d
"{\"index\":{\"fields\":[\"docType\",\"owner\"]},
\"name\":\"indexOwner\",
\"ddoc\":\"indexOwnerDoc\",
\"type\":\"json\"}" http://hostname:port/mychannel_marbles/_index
删除索引：
curl -X DELETE http://localhost:5984/mychannel_marbles/_index/indexOwnerDoc/json/indexOwner -H "accept: */*" -H "Host: localhost:5984"
转载请注明来源
