Cloud Function to import data into CloudSQL from cloud storage bucket but getting already schema exist error

I'm trying to import data into CloudSQL instance from cloud storage bucket using cloud function.

How can i delete schema's before importing the data using a same cloud function? https://cloud.google.com/sql/docs/mysql/admin-api/rest/v1beta4/instances/import in below code where do i need to put delete all existing schema's apart from public schema?

const {google} = require('googleapis');
var sqlAdmin = google.sqladmin('v1beta4');

authorize(function(authClient) {
  var request = {

    project: 'my-project',  // TODO: Update placeholder value.


    instance: 'my-instance',  // TODO: Update placeholder value.

    resource: {
      importContext: {

      kind: "sql#importContext",
      fileType: "SQL", // CSV

      uri: <bucket path>,

      database: <database-name>
      // Options for importing data as SQL statements.
      // sqlimportOptions: {
      //   /**
    },

    auth: authClient,
  };

  sqlAdmin.instances.import(request, function(err, response) {
    if (err) {
      console.error(err);
      return;
    }

    console.log(JSON.stringify(response, null, 2));
  });
});

function authorize(callback) {
  google.auth.getClient({
    scopes: ['https://www.googleapis.com/auth/cloud-platform']
  }).then(client => {
    callback(client);
  }).catch(err => {
    console.error('authentication failed: ', err);
  });
}