PostgreSQL field type to store string, int, or json - postgresql

Question

I want to store a table for variables with table definition like below
variable
--------
id int
var_type int 0: number, 1: string, 2: json
var_name int
var_value ??? varchar or jsonb?
If I use varchar, how to store the json type variable and if, I am using jsonb how to store the int and string?
The example json value that is stored,
[{"name": "Andy", "email" : "andy#mail.id"},{"name": "Cindy", "email" : "cindy#mail.id"}]
TIA
Beny

Answer 1

When you have data and you don't know the structure, use a single jsonb column. JSON can handle strings, numbers, and more JSON.
{
"string": "basset hounds got long ears",
"number": 23.42,
"json": [1,2,3,4,5]
}
Don't try to cram them all into a single array. Put them in separate rows.
One row: {"name": "Andy", "email" : "andy#mail.id"}
Another row: {"name": "Cindy", "email" : "cindy#mail.id"}
However, your example feels like its avoiding designing a schema. JSONB is useful, but overusing it defeats the point of a relational database.
create table people (
id bigserial primary key,
// Columns for known keys which can have constraints.
name text not null,
email text not null,
// JSONB for extra keys you can't predict.
data jsonb
)
Use the JSON operators to query individual pairs.
select
name, email, data->>'favorite dog breed'
from some_table