dynamodb-update-expression
A small library providing the solution to generate DynamoDB update expression by comparing the original data with update/remove JSON object.
Release History
- 0.1.16 Fix issue #6
- 0.1.15 updated the dependencies library, especially there is a fix for array object in deepmerge module
- 0.1.14 resolve #5 update the README.md
- 0.1.13 Cleaned up an unnecessary console.log for issue #3
- 0.1.0 Initial release
Installation
npm install dynamodb-update-expression --save
Usage
var dynamodbUpdateExpression = require('dynamodb-update-expression');
var updateExpression = dynamodbUpdateExpression.getUpdateExpression(original, update);
var removeExpression = dynamodbUpdateExpression.getRemoveExpression(original, remove);
Where original, update, and remove should be a JSON object.
For example:
Original JSON:
var original = {
"firstName": "John",
"lastName": "Doe",
"phones": [
"1111-2222-333",
"5555-4444-555"
],
"family": [
{
"id": 1,
"role": "father"
}
],
"profile": {
"jobTitle": "Manager",
"company": "ACME Inc",
"business": {
"license": "ABCD-123-LIC",
"website": "www.acme.com"
}
}
};
Update JSON:
var updates = {
"lastName": "L. Doe", // Will be updated
// List of primitives
"phones": [
"1111-2222-333", // Original will be MERGED with this list
"2222-4444-555"
],
// List of object
"family": [
{
"id": 2,
"role": "mother"
} // Original will be REPLACED by this (because of: deepmerge library bug)
],
// Nested Object
"profile": {
"office": "1234 Market Street", // Add this element
"business": {
"website": "www.acmeinc.com", // Update this element
"phone": "111222333" // Add this element
},
"company": "" // Remove this element because it is an empty string
}
};
Remove JSON:
var removes = {
"phones": [
"1111-2222-333" // Will remove this number
],
"profile": {
"business": {
"website": "www.acmeinc.com", // Will remove this element
"phone": "111222333" // Won't be removed (not exists in original)
}
}
};
Output
Sample output
{
"UpdateExpression": "SET #lastName = :lastName, #phones = :phones, #family = :family, #profilebusinesswebsite = :profilebusinesswebsite, #profilebusinessphone = :profilebusinessphone, #profileoffice = :profileoffice REMOVE #profilecompany",
"ExpressionAttributeNames": {
"#lastName": "lastName",
"#phones": "phones",
"#family": "family",
"#profilebusinesswebsite": "profile.business.website",
"#profilebusinessphone": "profile.business.phone",
"#profileoffice": "profile.office",
"#profilecompany": "profile.company"
},
"ExpressionAttributeValues": {
":lastName": "L. Doe",
":phones": [
"1111-2222-333",
"5555-4444-555",
"2222-4444-555"
],
":family": [
{
"id": 2,
"role": "mother"
}
],
":profilebusinesswebsite": "www.acmeinc.com",
":profilebusinessphone": "111222333",
":profileoffice": "1234 Market Street"
}
}
{
"UpdateExpression": "REMOVE #family, #profile.#business.#website SET #phones = :phones",
"ExpressionAttributeNames": {
"#profile": "profile",
"#business": "business",
"#website": "website",
"#family": "family",
"#phones": "phones"
},
"ExpressionAttributeValues": {
":phones": [
"5555-4444-555",
"9999-8888-777"
]
}
}
Tests
mocha test.js