GraphQL Variables
Variables simplify GraphQL queries and mutations by letting you pass data separately. A GraphQL request can be split into two sections: one for the query or mutation, and another for variables.
Variables can be declared after the query or mutation and are passed like arguments to a function and begin with $.
Query Example :
query post($filter: PostFilter) {
queryPost(filter: $filter) {
title
text
author {
name
}
}
}
Variables:
{
"filter": {
"title": {
"eq": "First Post"
}
}
}
Result:
{
"data": {
"queryPost": [{
"title": "First Post",
"text": "Hello world!",
"author": [{
"name": "A.N. Author"
}]
}]
}
}
Mutation Example :
mutation addAuthor($author: AddAuthorInput!) {
addAuthor(input: [$author]) {
author {
name
posts {
title
text
}
}
}
}
Variables:
{
"author": {
"name": "A.N. Author",
"dob": "2000-01-01",
"posts": [{
"title": "First Post",
"text": "Hello world!"
}]
}
}
Result:
{
"data": {
"addAuthor": {
"author": [{
"name": "A.N. Author",
"posts": [{
"title": "First Post",
"text": "Hello world!"
}]
}]
}
}
}