DynamoDB basic operation of (a)

First, create a table 

. 1 var the AWS = the require ( "aws-SDK" );
  2 AWS.config.update ({
  . 3 Region: "US-2-West",                           // used which area aws service 
 4 endpoint: "http: // localhost : 8000 " // dynamodb position 
 . 5 });
  . 6 var dynamodb = new new AWS.DynamoDB ();
  . 7 
 . 8 var the params = {
  . 9 the TableName:" Movies ", // table 
10 KeySchema: [        // primary key 
11 {AttributeName:" year ", KeyType:" HASH "},   // partition key partitioning key
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 });

Second, the increase in entries 

. 1  var docClient = new new AWS.DynamoDB.DocumentClient ();
 2  var Table = "Movies" ;
 . 3  var year =, 2015 ;
 . 4  var title = "of The New Big Movie" ;
 . 5  var the params = {
 . 6      the TableName: Table, // table to operate 
. 7      Item: {
 . 8          "year": year, // primary key - inter-partition 
. 9          "title": title, // primary key - sort key 
10          "info": {      // other properties 
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 });

 Third, access entries 

. 1  var docClient = new new AWS.DynamoDB.DocumentClient ()
 2  var Table = "Movies"; // table must fill 
. 3  var year =, 2015;   // partition key to be queried 
. 4  var title = "of The New Big Movie"; // sort key to be queried is provided if the table creating a composite primary key, then the partition key sort key must exist 
. 5  var the params = {the TableName: table, key: { "year": year, "title" : title}};
 . 6 docClient.get (the params, function (ERR, Data) {
 . 7      IF (ERR) {
 . 8          console.error ( "Unable to Read Error the JSON Item:.", the JSON.stringify (ERR, null ,2));
 9     } else {
10         console.log("GetItem succeeded:", JSON.stringify(data, null, 2));
11     }
12 });

 Fourth, the updated item 

. 1  var Table = "Movies" ;
 2  var year =, 2015 ;
 . 3  var title = "of The New Big Movie"; // the Update The Item, UNCONDITIONALLY, 
. 4  var the params = {
 . 5      the TableName: Table, Key: {
 . 6          "year" : year, // partition key 
. 7          "title": title // sort key interface must update the primary key 
. 8      }, UpdateExpression: "SET = info.rating: R & lt, = info.plot: P, = info.actors: A" , // want to change the value of the expression 
9      ExpressionAttributeValues: {       // value you want to change the assignment 
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 });

Fifth, delete items 

. 1  var Table = "Movies" ;
 2  var year =, 2015 ;
 . 3  var title = "of The New Big Movie" ;
 . 4  var the params = {
 . 5      the TableName: Table, // wait table delete operation 
. 6      Key: {
 . 7          "year" : year, // partition key 
. 8          "title": title // sort key 
. 9      },
 10      ExpressionAttributeNames: { "U #": "the User" },
 . 11      conditionExpression: "= #U: Val", // deletion condition expression formula 
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 });

 Sixth, batch query 

 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 });

 

 When using more than the recommended operation database operation, the operation DynamoDB database in two ways, see DynamoBD Another common operation (b), this approach is more complicated, not recommended