Query

Description

This function searches for items based on the values of the primary key values. 

For more information, see Query.

Category

History

ColdFusion (2021 release): Added this function.

Syntax

serviceHandle.query(requestParameters)

Parameters

See request parameters of Query.

Example

<cfscript> 
  cred = { 
    "credentialAlias" : "myalias", 
    "vendorName" : "AWS", 
    "region" : "us-east-2", 
    "secretAccessKey" : "xxxxx", 
    "accessKeyId" : "xxxx" 
  } 
  config = { 
    "serviceName" = "DYNAMODB" 
  } 
  dynamo = getCloudService(cred, config) 
 // Stage 1: create a table 
  tableName="MusicTableForDemo" 
  tableStruct={ 
    TableName : "#tableName#", 
    KeySchema:[ 
        { AttributeName: "Artist", KeyType: "HASH"},  // Partition key 
        { AttributeName: "SongTitle", KeyType: "RANGE"}  // Sort key 
    ], 
    AttributeDefinitions:[ 
        { AttributeName: "Artist", AttributeType: "S" }, 
        { AttributeName: "SongTitle", AttributeType: "S" } 
    ], 
    ProvisionedThroughput:{ 
        ReadCapacityUnits: 10, 
        WriteCapacityUnits: 10 
    } 
 } 
 
 try{ 
    createResponse=dynamo.createTable(tableStruct) 
    writeOutput("Table created successfully") 
 } 
 catch (any e){ 
    writeDump(e) 
 } 
 
// Stage 2: batch write item 
  batchWriteItemStruct={ 
    "RequestItems":{ 
      "#tableName#":[ 
        { 
          "PutRequest":{ 
            "Item":{ 
              "Artist":{"S":"Beatles"}, 
              "SongTitle":{"S":"Yesterday"} 
            } 
          } 
        }, 
        { 
          "PutRequest":{ 
            "Item":{ 
              "Artist":{"S":"Rolling STones"}, 
              "SongTitle":{"S":"Angie"} 
            } 
          } 
        }, 
        { 
          "PutRequest":{ 
            "Item":{ 
              "Artist":{"S":"Beatles"}, 
              "SongTitle":{"S":"Hey Jude"} 
            } 
          } 
        }, 
        { 
          "PutRequest":{ 
            "Item":{ 
              "Artist":{"S":"Beatles"}, 
              "SongTitle":{"S":"Let it be"} 
            } 
          } 
        }, 
        { 
          "PutRequest":{ 
            "Item":{ 
              "Artist":{"S":"Lionel Richie"}, 
              "SongTitle":{"S":"Hello"} 
            } 
          } 
        }, 
        { 
          "PutRequest":{ 
            "Item":{ 
              "Artist":{"S":"Adele"}, 
              "SongTitle":{"S":"Hello, I Love You"} 
            } 
          } 
        }, 
        { 
          "PutRequest":{ 
            "Item":{ 
              "Artist":{"S":"Adele"}, 
              "SongTitle":{"S":"Hello"} 
            } 
          } 
        } 
      ] 
    } 
  } 
   
  try{ 
    qriteItemResponse=dynamo.batchWriteItem(batchWriteItemStruct,{"hasType":true}) 
    writeOutput("Items inserted successfully") 
    writeDump(qriteItemResponse) 
 
  } 
  catch (any e){ 
    writeDump(e) 
  } 
 
// Stage 3: query the table 
// Return a single song, by primary key 
queryStruct={ 
  "TableName":"#tableName#", 
  "KeyConditionExpression": "Artist =:a and SongTitle =:t", 
  "ExpressionAttributeValues": { 
        ":a": "Beatles", 
        ":t": "Yesterday" 
    } 
} 
 
// Output of first case 
try{ 
  queryResponse=dynamo.query(queryStruct,{"customResponse":true}) 
  writeOutput("Items returned successfully") 
  writeDump(queryResponse) 
} 
catch (ay e){ 
  writeDump(e) 
} 
 
// Return all songs by a particular artist 
queryStructArtist={ 
  "TableName":"#tableName#", 
  "KeyConditionExpression":"Artist =:a", 
  "ExpressionAttributeValues":{ 
    ":a": "Beatles" 
  } 
} 
 
// Output of second case 
try{ 
  queryResponseArtist=dynamo.query(queryStructArtist,{"customResponse":true}) 
  writeOutput("Items returned successfully") 
  writeDump(queryResponseArtist) 
} 
catch (ay e){ 
  writeDump(e) 
} 
 
// Return all of the songs by an artist matching first part of title 
queryStructFirstPart={ 
  "TableName":"#tableName#", 
  "KeyConditionExpression":"Artist =:a and begins_with(SongTitle,:t)", 
  "ExpressionAttributeValues":{ 
    ":a":"Adele", 
    ":t":"Hello" 
  } 
} 
 
// Output of third case 
try{ 
  queryResponseFirstPart=dynamo.query(queryStructFirstPart,{"customResponse":true}) 
  writeOutput("Items returned successfully") 
  writeDump(queryResponseFirstPart) 
} 
catch (ay e){ 
  writeDump(e) 
} 
</cfscript> 

Output

Query output
Query output

 Adobe

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