CODEWITHSUNDEEP
amazon-web-servicesamazon-dynamodb
daniel
daniel

Reputation: 383

Amazon DynamoDB Query for Items whose key contains a substring

I am using an Amazon DynamoDB database, and I have a list of items with various strings as the key. I want to query for items whose key contains a substring. For example, if some of the keys are:

"abcd_aaa"
"abcd_bbb"
"abcd_ccc"

I want to query where a key contains "abcd" and these 3 items will be returned. Is this possible?

Upvotes: 38

Views: 49581

Answers (2)

Kevin
Kevin

Reputation: 449

Scan will work

something like this

var params = {
      TableName: "TABLE",
      ScanFilter: {
           "id": {
                ComparisonOperator: "CONTAINS",
                AttributeValueList: ["abcd"]
           }
      }
 };

 var template = null;
 ddb.scan(params, function (err, data) {
      if (err) {
           console.error("Unable to query. Error:", JSON.stringify(err, null, 2));
      } else {
           //console.log("Query succeeded.");
           data.Items.forEach(function (item) {
                console.log(item);
           });
      }
 });

Upvotes: -5

b-s-d
b-s-d

Reputation: 5143

You can only query the hashKey using the equality operator (EQ). That being said if those values ("abcd_aaa", "abcd_bbb", "abcd_ccc") belong to your hashKey then you have to provide them entirely. On the other hand, the Query operation does allow partial matching on the rangeKey with the option of a few additional comparison operators:

EQ | LE | LT | GE | GT | BEGINS_WITH | BETWEEN

See the Query documentation for more details.

One possibility would be to use a hashKey and rangeKey where the first part of your code would be the hashKey and the last the rangeKey, example:

hashKey : abcd
rangeKey : aaa

By doing this when you query by hashKey (abcd), you would receive all three records sorted by the rangeKey

Upvotes: 39

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