Mule ESB : Traverse a json payload and make where clause condition for Salesforce

Question

Following is the input in terms of json payload and what is required is to form a where clause statement which I can use for salesforce query.

Note: The number of query fields can vary from 1 to n.

Input payload

{
"object_type": "contact",
"query_fields": [
{
    "field_name": "CreatedById", "field_value": "005g0000003qelYAAQ"},
{
    "field_name": "BillingState", "field_value": "KA"}
]
}

Sample output:

#[json:query_fields[0]/field_name] = '#[json:query_fields[0]/field_value]' AND #[json:query_fields[0]/field_name] = '#[json:query_fields[0]/field_value]'

Answer 1

I figured out the solution to this problem and thought of sharing the same with us all.

Step 1: Transformed the above mentioned input payload into array:

    <dw:set-payload><![CDATA[%dw 1.0
%output application/java
---
payload map {
    field_name : $.field_name,
    field_value : $.field_value
}]]></dw:set-payload>

Step 2: Used an expression component to traverse the array and take the value of it so that I can use the values to form a where clause for the Salesforce query further in my flow.

<![CDATA[String wrcls ="";
int m=1;
int n=0;
for (String counter : flowVars.queryfields)
{
wrcls += payload[m].field_name[n] + " = " + "'" + payload[m].field_value[n] + "'"  +  " AND " 
m = m + 1;
n = n + 1;

}

payload = wrcls;

payload = payload.replaceAll(" AND $", "");]]>