when we modify a customized application, we can see the field id in the html page

such as "https://ap1.salesforce.com/00N90000002m2KA?setupid=CustomObjects"

but my question is how to get such id "00N90000002m2KA" from API level by field name?

because the http POST request only have such keyword,I want to know what field is it

Thanks

Hi All

I am a new developer. I want to get the detail objects field's id by rest api.

But I can't find it.

I think SOAP api can do this,right?

With rare exceptions, all objects in the API have a field of type ID that is named Id

 and contains a unique identifier for each record in the object. It is analogous to a primary key in relational databases. 

ID fields in the Salesforce user interface contain 15-character, base-62, case-sensitive strings. Each of the 15 characters can be a numeric digit (0-9), a lowercase letter (a-z), or an uppercase letter (A-Z). Two unique IDs may only be different by a change in case.

when we modify a customized application, we can see the field id in the html page

such as "https://ap1.salesforce.com/00N90000002m2KA?setupid=CustomObjects"

but my question is how to get such id "00N90000002m2KA" from API level by field name?

because the http POST request only have such keyword,I want to know what field is it

Thanks