运行自己的事务

session = driver.session({ database: 'neo4j' })

let session = driver.session({ database: 'neo4j' })  (1)
try {
  let result = await session.executeRead(async tx => { (2)
    return await tx.run(`  (3)
      MATCH (p:Person) WHERE p.name STARTS WITH $filter
      RETURN p.name AS name ORDER BY name
      `, {filter: 'Al'}
    )
  })
  for(let record in result.records) {  (4)
    console.log(record.get('name'))
  }
  console.log(
    `The query \`${result.summary.query.text}\`` +
    `returned ${result.records.length} nodes.\n`
  )
} finally {
  session.close()
}

const neo4j = require('neo4j-driver');

(async () => {
  const URI = '{neo4j-database-uri}'
  const USER = '{neo4j-username}'
  const PASSWORD = '{neo4j-password}'
  let driver, session
  let employeeThreshold = 10

  try {
    driver = neo4j.driver(URI, neo4j.auth.basic(USER, PASSWORD))
    await driver.verifyConnectivity()
  } catch(err) {
    console.log(`-- Connection error --\n${err}\n-- Cause --\n${err.cause}`)
    await driver.close()
    return
  }

  session = driver.session({ database: 'neo4j' })
  for(let i=0; i<100; i++) {
    const name = `Neo-${i.toString()}`
    const orgId = await session.executeWrite(async tx => {
      let result, orgInfo

      // Create new Person node with given name, if not already existing
      await tx.run(`
        MERGE (p:Person {name: $name})
        RETURN p.name AS name
        `, { name: name }
      )

      // Obtain most recent organization ID and number of people linked to it
      result = await tx.run(`
        MATCH (o:Organization)
        RETURN o.id AS id, COUNT{(p:Person)-[r:WORKS_FOR]->(o)} AS employeesN
        ORDER BY o.createdDate DESC
        LIMIT 1
      `)
      if(result.records.length > 0) {
        orgInfo = result.records[0]
      }

      if(orgInfo != undefined && orgInfo['employeesN'] == 0) {
        throw new Error('Most recent organization is empty.')
        // Transaction will roll back -> not even Person is created!
      }

      // If org does not have too many employees, add this Person to that
      if(orgInfo != undefined && orgInfo['employeesN'] < employeeThreshold) {
        result = await tx.run(`
          MATCH (o:Organization {id: $orgId})
          MATCH (p:Person {name: $name})
          MERGE (p)-[r:WORKS_FOR]->(o)
          RETURN $orgId AS id
          `, { orgId: orgInfo['id'], name: name }
        )

      // Otherwise, create a new Organization and link Person to it
      } else {
        result = await tx.run(`
          MATCH (p:Person {name: $name})
          CREATE (o:Organization {id: randomuuid(), createdDate: datetime()})
          MERGE (p)-[r:WORKS_FOR]->(o)
          RETURN o.id AS id
          `, { name: name }
        )
      }

      // Return the Organization ID to which the new Person ends up in
      return result.records[0].get('id')
    })
    console.log(`User ${name} added to organization ${orgId}`)
  }
  await session.close()
  await driver.close()
})()

let session = driver.session({ database: 'neo4j' })
let transaction = await session.beginTransaction()

// use tx.run() to run queries
//     tx.commit() to commit the transaction
//     tx.rollback() to rollback the transaction

await transaction.commit()
await session.close()

const neo4j = require('neo4j-driver');
const URI = '{neo4j-database-uri}';
const USER = '{neo4j-username}';
const PASSWORD = '{neo4j-password}';

(async () => {

  try {
    driver = neo4j.driver(URI, neo4j.auth.basic(USER, PASSWORD))
    await driver.verifyConnectivity()
  } catch(err) {
    console.log(`-- Connection error --\n${err}\n-- Cause --\n${err.cause}`)
    await driver.close()
    return
  }

  let customerId = await createCustomer(driver)
  let otherBankId = 42
  await transferToOtherBank(driver, customerId, otherBankId, 999)
  await driver.close()
})()

async function createCustomer(driver) {
  let { records } = await driver.executeQuery(`
      MERGE (c:Customer {id: randomUUID()})
      RETURN c.id AS id
    `, {},
    { database: 'neo4j' }
  )
  return records[0].get("id")
}

async function transferToOtherBank(driver, customerId, otherBankId, amount) {
  const session = driver.session({ database: 'neo4j' })
  const tx = await session.beginTransaction()
  try {
    if(! checkCustomerBalance(tx, customerId, amount))
      return

    try {
      decreaseCustomerBalance(tx, customerId, amount)
      await tx.commit()
    } catch (error) {
      requestInspection(customerId, otherBankId, amount, e)
      throw error  // roll back
    }

    await otherBankTransferApi(customerId, otherBankId, amount)
    // Now the money has been transferred => can't rollback anymore
    // (cannot rollback external services interactions)
  } finally {
    await session.close()
  }
}

async function checkCustomerBalance(tx, customerId, amount) {
  result = await tx.run(`
    MATCH (c:Customer {id: $id})
    RETURN c.balance >= $amount AS sufficient
    `, { id: customerId, amount: amount },
    { database: 'neo4j' }
  )
  return result.records[0].get('sufficient')
}

async function otherBankTransferApi(customerId, otherBankId, amount) {
  // make some API call to other bank
}

async function decreaseCustomerBalance(tx, customerId, amount) {
  await tx.run(`
    MATCH (c:Customer {id: $id})
    SET c.balance = c.balance - $amount
    `, { id: customerId, amount: amount }
  )
}

async function requestInspection(customerId, otherBankId, amount, error) {
  // manual cleanup required; log this or similar
  console.log('WARNING: transaction rolled back due to exception:')
  console.log(error)
}

let session = driver.session({ database: 'neo4j' })
const people_n = await session.executeRead(
  async tx => { return await tx.run('MATCH (a:Person) RETURN count(a)') },
  { timeout: 5000, metadata: {'app_name': 'people'} }  // TransactionConfig
)

let session = driver.session({database: 'neo4j'})
try {
  // use session to run queries
} finally {
  await session.close()
}