在Gatsby模板中引用查询中使用的GraphQL变量？

query($tag: String!) {
  allMarkdownRemark(filter: { frontmatter: { tags: { eq: $tag } } }) {
    edges {
      node {
        frontmatter {
          title
        }
      }
    }
  }
}

import React from "react"
import { graphql } from "gatsby"

const TagPage = ({ data }) => {
  const posts = data.allMarkdownRemark.edges

  return (
    <div>
      <h1>Posts with Tag: {tag}</h1>
      <ul>
        {posts.map(({ node }) => (
          <li key={node.frontmatter.title}>{node.frontmatter.title}</li>
        ))}
      </ul>
    </div>
  )
}

export const query = graphql`
  query($tag: String!) {
    allMarkdownRemark(filter: { frontmatter: { tags: { eq: $tag } } }) {
      edges {
        node {
          frontmatter {
            title
          }
        }
      }
    }
  }
`

export default TagPage