Question 89161 in PostgreSQL Question posted in
The official documentation can be found here.

How do I find the data type of a cypher query result in Apache AGE? – Postgresql

Assuming I have a customer graph in apache AGE, and I make the following query:

    SELECT *
    FROM cypher("customers",
    $$
        MATCH (p:person)
        RETURN p.first_name, p.last_name
    $$
    ) as (first_name agtype, last_name agtype)

I get the following result:

     first_name  | last_name 
    -------------+-----------
     John        | Doe
     Matthew     | Martinez
     Melissa     | Moore

How do I determine the data type of these 2 columns? I know that internally AGE keeps track of different types (like int, float etc), but to postgres these columns are all of type ‘agtype’.

Looking at the above example, I already know that first_name and last_name are VARCHAR. So if I wanted to CAST first_name from ‘agtype’ to VARCHAR I could, but is there any way to determine this without having to guess the type?

For example, if a query from AGE returns a column zip_code, and the zip_code property is stored internally in AGE as an INT, how would I CAST agtype zip_code to the correct type instead of having to guess between INT and VARCHAR?

Tags:

2

Answers


  1. 0

    Try using apoc.meta.type feature.

    An example,

    CREATE (p:Person { first_name: ‘John’, last_name: ‘Doe’ })
    RETURN apoc.meta.types(properties(p))

    Try using this method with your queries by wrapping them around this.

    Login or Signup to reply.
  2. 0

    It doesn’t seem like there is an existing function that outputs the datatype as of now; however, you can find a workaround such as:

    SELECT *
FROM cypher('customers', $$
    MATCH (p:person)
    RETURN p.first_name, toInteger(p.first_name) IS NULL
$$) AS (first_name agtype, is_string agtype);

    Which results in the output:

    first_name | is_string
------------+-----------
 "John"     | true
 "Matthew"  | true
 "Melissa"  | true

    This should work if you are just trying to differentiate between an integer and something else (for example a varchar), which can be implemented in the zip code example you have given.

    Login or Signup to reply.
Please signup or login to give your own answer.

Back To Top
Search