GraphQL Filter Specifications: QBE

While you can perform equality comparisons using GraphQL arguments, you can perform all other comparisons using the query-by-example (QBE) syntax.

QBE is analogous to where clause in SQL queries and is a slightly modified form of SODA QBE expression. To use this feature, you can specify the list of predicates for a table in the check clause, and this clause is specified after the table name and before the list of directives.

For example, driver(check:{points:{_gt: 360}}).

Each predicate has the alias name for the column, followed by a QBE operator and then the comparison value. In the example above, points is the alias, _GT is the operator which will perform greater than operation and 360 is the comparison value, this is equivalent to "where points > 360".

Oracle AI Database supports the following categories of operators for GraphQL developers:

• Relational Operators : Includes comparison operators such as _eq (equal to), _ne (not equal to) etc.
• Logical Operators: Includes operators such as _and and _or to combine the predicates.
• Item Method Operators: Includes operators such as _lower, _upper etc., which transforms the value and then uses for further filtering.