DynamoDB的基本操作（一）
作者：互联网
一、创建表
1 var AWS = require("aws-sdk");
2 AWS.config.update({
3 region: "us-west-2", //使用哪个区域的aws服务
4 endpoint: "http://localhost:8000" //dynamodb位置
5 });
6 var dynamodb = new AWS.DynamoDB();
7
8 var params = {
9 TableName: "Movies",//表名
10 KeySchema: [ //主键
11 {AttributeName: "year", KeyType: "HASH"}, //Partition key 分区键
12 {AttributeName: "title", KeyType: "RANGE"} //Sort key 排序键
13 ],
14 AttributeDefinitions: [//主键数据类型
15 {AttributeName: "year", AttributeType: "N"},//N Number
16 {AttributeName: "title", AttributeType: "S"} //S String
17 ],
18 ProvisionedThroughput: { //DynamoDB吞吐量配置
19 ReadCapacityUnits: 10,
20 WriteCapacityUnits: 10
21 }
22 };
23 dynamodb.createTable(params, function (err, data) {
24 if (err) {
25 console.error("Unable to create table. Error JSON:", JSON.stringify(err, null, 2));
26 } else {
27 console.log("Created table. Table description JSON:", JSON.stringify(data, null, 2));
28 }
29 });
二、增加项
1 var docClient = new AWS.DynamoDB.DocumentClient();
2 var table = "Movies";
3 var year = 2015;
4 var title = "The Big New Movie";
5 var params = {
6 TableName: table,//要操作的表名
7 Item: {
8 "year": year,//主键-分区间
9 "title": title,//主键-排序键
10 "info": { //其他属性
11 "plot": "Nothing happens at all.", "rating": 0
12 }
13 }
14 };
15 console.log("Adding a new item...");
16 docClient.put(params, function (err, data) {
17 if (err) {
18 console.error("Unable to add item. Error JSON:", JSON.stringify(err, null, 2));
19 } else {
20 console.log("Added item:", JSON.stringify(data, null, 2));
21 }
22 });
三、获取项
1 var docClient = new AWS.DynamoDB.DocumentClient()
2 var table = "Movies";//表名必须填
3 var year = 2015; //待查询的分区键
4 var title = "The Big New Movie";//待查询的排序键 如果表建立时设置为复合主键的话，分区键排序键必须都存在
5 var params = {TableName: table, Key: {"year": year, "title": title}};
6 docClient.get(params, function (err, data) {
7 if (err) {
8 console.error("Unable to read item. Error JSON:", JSON.stringify(err, null, 2));
9 } else {
10 console.log("GetItem succeeded:", JSON.stringify(data, null, 2));
11 }
12 });
四、更新项
1 var table = "Movies";
2 var year = 2015;
3 var title = "The Big New Movie"; // Update the item, unconditionally,
4 var params = {
5 TableName: table, Key: {
6 "year": year,//分区键
7 "title": title//排序键 主键在update接口必须
8 }, UpdateExpression: "set info.rating = :r, info.plot=:p, info.actors=:a",//想要改变值的表达式
9 ExpressionAttributeValues: { //为想要改变的值赋值
10 ":r": 5.5, ":p": "Everything happens all at once.", ":a": ["Larry", "Moe", "Curly"]
11 }, ReturnValues: "UPDATED_NEW"//返回更新值，即下中data
12 };
13 console.log("Updating the item...");
14 docClient.update(params, function (err, data) {
15 console.log(data);
16 if (err) {
17 console.error("Unable to update item. Error JSON:", JSON.stringify(err, null, 2));
18 } else {
19 console.log("UpdateItem succeeded:", JSON.stringify(data, null, 2));
20 }
21 });
五、删除项
1 var table = "Movies";
2 var year = 2015;
3 var title = "The Big New Movie";
4 var params = {
5 TableName: table,//待删除操作的表
6 Key: {
7 "year": year,//分区键
8 "title": title//排序键
9 },
10 ExpressionAttributeNames:{"#u":"User"},
11 ConditionExpression: "#u = :val",//删除条件表达式
12 ExpressionAttributeValues: {
13 ":val": 5.0 //条件值
14 }
15 };
16 console.log("Attempting a conditional delete...");
17 docClient.delete(params, function (err, data) {
18 if (err) {
19 console.error("Unable to delete item. Error JSON:", JSON.stringify(err, null, 2));
20 } else {
21 console.log("DeleteItem succeeded:", JSON.stringify(data, null, 2));
22 }
23 });
六、批量查询
1 var params = {
2 RequestItems: {
3 "GsdSubDevices": {
4 Keys: [
5 {
6 "Mac": "haha"
7 },
8 {
9 "Mac": "111"
10 },
11 {
12 "Mac": "222"
13 }
14 ]
15 }
16 }
17 };
18 console.log("requestArr===>" + JSON.stringify(requestArr));
19 docClient.batchGet(params, function (err, data) {
20 if (err) {
21 console.error("Unable to read item. Error JSON:", JSON.stringify(err, null, 2));
22 } else {
23
24 }
25 });
推荐操作数据库时使用以上操作，操作DynamoDB数据库有两种方式，另一种见DynamoBD常见操作（二），这种方式比较繁琐，不推荐使用
标签：console,err,title,DynamoDB,JSON,year,var,基本操作 来源： https://www.cnblogs.com/yayaonly/p/12114396.html