GraphQL Filter Specifications: Arguments
Filtering using GraphQL in Oracle AI Database is achieved by using arguments.
Arguments in GraphQL is analogous to where clause in SQL queries. The
syntax for defining the argument includes one or many comma separated predicates which
takes the field name and its corresponding value that needs to be filtered in the
output.
SELECT JSON_SERIALIZE(data PRETTY) AS data FROM GRAPHQL('
driver (teamId: 301) {
id: driver_id
name
points
teamId: team_id
}
');The above example, teamID: 301 is the filtering argument. The example would
produce details of the
driver where the teamID field
is equal to
301:DATA
--------------------------------------------------------------------------------
{
"id" : 101,
"name" : "Lando Norris",
"points" : 282,
"teamId" : 301
}
{
"id" : 102,
"name" : "Oscar Piastri",
"points" : 384,
"teamId" : 301
}
2 rows selected.Using a specific field argument does not mandate that the field must be present in the
output. So the following example would not produce an error where
team_id used as a filter argument is not specified in the
output:SELECT JSON_SERIALIZE(data PRETTY) AS data FROM GRAPHQL('
driver (team_id: 301) {
id: driver_id
name
points
}
');The output would just display the
id, name and
points of the driver object where
team_id
is equal to
301:DATA
--------------------------------------------------------------------------------
{
"id" : 101,
"name" : "Lando Norris",
"points" : 282
}
{
"id" : 102,
"name" : "Oscar Piastri",
"points" : 384
}
2 rows selected.LIMIT Argument
The GraphQL limit argument in Oracle AI Database limits
the output to the specified number of JSON objects. The syntax is simple - the
keyword limit, followed by a : and then an
integer which defines the limit.
The
limit:5 in the following example would retrieve only 5 objects
irrespective of the number of objects in the
table:SELECT JSON_SERIALIZE(data PRETTY) AS data FROM GRAPHQL('
driver (limit: 5) {
id: driver_id
name
points
}
');