Graphql get aggregation of dynamic data - node.js

Question

I am using graphql with node js on oracle db to fetch some data. I have two tables customer and sub_customer with the below schemas:
const Customer = new GraphQLObjectType({
description: 'Customer data schema',
name: 'Customer',
fields: () => ({
name: {
type: GraphQLString,
sqlColumn: 'NAME',
},
city: {
type: GraphQLString,
sqlColumn: 'CITY'
},
region: {
type: GraphQLString,
sqlColumn: 'REGION'
},
country: {
type: GraphQLString,
sqlColumn: 'COUNTRY'
},
gender: {
type: GraphQLString,
sqlColumn: 'GENDER'
},
emp_id: {
type: GraphQLString,
sqlColumn: 'EMP_ID'
},
sub_id: {
type: new GraphQLList(Subcustomer),
sqlJoin: (Subcustomer, Customer, args) => `${Subcustomer}.REGION_CODE = ${Customer}.REGION`
}
})
});
Customer._typeConfig = {
sqlTable: 'CUSTOMER',
uniqueKey: ['NAME','EMP_ID']
}
const Subcustomer = new GraphQLObjectType({
description: 'Subcustomer data schema',
name: 'Subcustomer',
fields: () => ({
sub_customer_id: {
type: GraphQLString,
sqlColumn: 'SUB_CUSTOMER_ID',
},
region_code: {
type: GraphQLString,
sqlColumn: 'REGION_CODE'
},
customer: {
type: new GraphQLList(Customer),
args: {
emp_id: {
type: GraphQLString
}
},
where: (customer, args, context) => {
if (Object.keys(args).length === 0) {
return false;
}
let whereClause = '1 = 1';
if (args.emp_id != undefined) {
whereClause += `\n AND ${customer}."EMP_ID" = '${args.emp_id}'`;
}
return whereClause;
},
sqlJoin: (Subcustomer, Customer, args) => `${Subcustomer}.REGION_CODE = ${Subcustomer}.REGION`
}
})
});
Subcustomer._typeConfig = {
sqlTable: 'SUB_CUSTOMER',
uniqueKey: 'REGION_CODE'
}
And this is my Query:
const QueryRoot = new GraphQLObjectType({
description: 'global query object',
name: 'RootQuery',
fields: () => ({
customer: {
type: new GraphQLList(Customer),
args: {
emp_id: {
description: 'Emp Id',
type: GraphQLString
},
name: {
description: 'Customer Name',
type: GraphQLString
}
},
where: (customer, args, context) => {
if (Object.keys(args).length === 0) {
return false;
}
let whereClause = '1 = 1';
if (args.emp_id != undefined) {
whereClause += `\n AND ${customer}."EMP_ID" = :emp_id`;
}
if (args.name != undefined) {
whereClause += `\n AND ${customer}."NAME" = :name`;
}
return whereClause;
},
resolve: (parent, args, context, resolveInfo) => {
return joinMonster(resolveInfo, context, sql => {
console.log('joinMaster', sql);
return database.simpleExecute(sql, args,{
outFormat: database.OBJECT
});
});
}
},
sub_customer: {
type: new GraphQLList(Subcustomer),
args: {
user_id: {
description: 'User Id',
type: GraphQLString
},
},
where: (user, args, context) => {
if (Object.keys(args).length === 0) {
return false;
}
let whereClause = '1 = 1';
if (args.user_id != undefined) {
whereClause += `\n AND ${user}."SUB_CUSTOMER_ID" = :user_id`;
}
return whereClause;
},
resolve: (parent, args, context, resolveInfo) => {
return joinMonster(resolveInfo, context, sql => {
console.log('joinMaster', sql);
return database.simpleExecute(sql, args,{
outFormat: database.OBJECT
});
});
}
}
})
})
I get correct results when I execute:
{
sub_customer(user_id: "123") {
sub_customer_id
customer(emp_id: "456") {
name
}
}
}
For getting count of records with static where clause I do:
sqlExpr: Customer => `(SELECT count(*) FROM CUSTOMER WHERE EMP_ID = '456')`
This gives me correct count. However I want the count of all the results returned when where clause is applied by the user and it could be dynamic.
I am using join monster as the library to fetch records. I could not find any way to execute this aggregation with dynamic where clauses.
Thank you.

Answer 1

The sqlExpr function is passed more than a single parameter. You have access to: tableAlias, args (for this field), context, and sqlASTNode:
https://join-monster.readthedocs.io/en/latest/API/#sqlExpr
The sqlASTNode has a parent property (not enumerable) that allows you to get the args of the parent field (Customer in your case). So you could make this field more dynamic too. Here's an example that I've not tested.
sqlExpr: (table, args, context, sqlASTNode) => {
let expr;
if (sqlASTNode.parent && sqlASTNode.parent.args && sqlASTNode.parent.args.emp_id != undefined) {
expr = '(SELECT count(*) FROM CUSTOMER WHERE EMP_ID = :emp_id)';
} else {
expr = 'null';
}
return expr;
}