Graphql execute where condition only if the argument is passed - node.js

Question

I am using graphql in node js for my oracle database wherein I connect to the remote database and fetch some details. I am fairly new to these technologies so please pardon me. I have a customer table with below schema:
const Customer = new GraphQLObjectType({
description: 'Customer data schema',
name: 'Customer',
fields: () => ({
name: {
type: GraphQLString,
sqlColumn: 'NAME',
},
city: {
type: GraphQLString,
sqlColumn: 'CITY'
},
country: {
type: GraphQLString,
sqlColumn: 'COUNTRY'
},
gender: {
type: GraphQLString,
sqlColumn: 'GENDER'
},
emp_id: {
type: GraphQLString,
sqlColumn: 'EMP_ID'
}
})
});
Customer._typeConfig = {
sqlTable: 'CUSTOMER',
uniqueKey: ['NAME','EMP_ID']
}
Using join monster I create my Query root as:
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) => {
return `${customer}."EMP_ID" = :emp_id AND ${customer}."NAME" = :name`;
},
resolve: (parent, args, context, resolveInfo) => {
return joinMonster(resolveInfo, context, sql => {
console.log('joinMaster', sql);
return database.simpleExecute(sql, args,{
outFormat: database.OBJECT
});
});
}
}
})
})
When I pass my query in graphql in browser with emp_id and name parameters I get data. But there are cases when I cannot pass any parameters and would want all the rows to be fetched.
When I do not send the parameters I get error as:
ORA-01008 : Not all variables bound
I want the arguments to be optional, and if I don't send them then it should return all rows.
Thank you.

Answer 1

Both the where and resolver functions are passed an args argument. This will have the parameter names and values if any. You can use that argument to build a dynamic where clause. Here's an untested example:
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
});
});
}
}
})
})
Since the where clause would then match the number of arguments, you shouldn't get the ORA-01008 error.