This lesson is about version control and we will be doing some Git-like operations that let us collaborate and time travel.
We'll be using the company phonebook example again. They are super busy and have decided to hire some contractors to help out for a few months. They want the contractor's details in the database and are going to make a branch of the database for the contractors to fill in their details.
Making a branch is like making a copy of the database. A benefit of this operation is that if a contractor makes a mistake and accidentally modifies data they should't, the changes will only impact the database branch. It also gives managers opportunity to review any changes before adopting them in the main database.
First we will connect to the server:
// TODO: Change teamname and username
const teamName = "teamname"
const username = "username"
const client = new TerminusClient.WOQLClient(
`https://cloud.terminusdb.com/${teamName}/`,
{ user: username, organization: teamName , db:"GettingStartedDB" }
);
//Assign your key to environment variable TERMINUSDB_ACCESS_TOKEN
client.setApiKey(process.env.TERMINUSDB_ACCESS_TOKEN);To make a branch, we use the client.branch() function. The client.branch("dev") will create a new branch WITHOUT going (checkout) to that branch.
Before we create the branch, let see what we have for now:
await client.getBranches();We only have the main branch. The main branch is the default branch that is created when you created a new database. Let's create the new branch:
await client.branch("contractors");We have created the contractors branch. Let's verify:
await client.getBranches();We can checkout to the new branch contractors using client.checkout("contractors"):
client.checkout("contractors");Now the contractors can add their details with this script add_contractors.js. We add the two contractors in similar manner as when we added Ethan in lesson 3:
Run the script:
$ node add_contractors.js
To verify we did things right, let's see if there are any changes in the current main branch, you can see the commit history with:
console.log("Main Commit History: ")
await getCommitHistory("main");[
{
Author: { '@type': 'xsd:string', '@value': 'undefined' },
'Commit ID': {
'@type': 'xsd:string',
'@value': '2zt3shmtvrrdsk63kvdxiwtzakthwb3'
},
Message: { '@type': 'xsd:string', '@value': 'Adding ethan' },
'Parent ID': 'terminusdb://ref/data/ValidCommit/a3ek3oouby4c098t4horxfrsbdgyy2m',
Time: { '@type': 'xsd:decimal', '@value': 1637909051.3614013 }
},
{
Author: { '@type': 'xsd:string', '@value': 'undefined' },
'Commit ID': {
'@type': 'xsd:string',
'@value': 'a3ek3oouby4c098t4horxfrsbdgyy2m'
},
Message: { '@type': 'xsd:string', '@value': 'updating 001' },
'Parent ID': 'terminusdb://ref/data/ValidCommit/h2oiyr244f8vxmibymtzl049qma6w11',
Time: { '@type': 'xsd:decimal', '@value': 1637909050.0255294 }
},
{
Author: { '@type': 'xsd:string', '@value': 'undefined' },
'Commit ID': {
'@type': 'xsd:string',
'@value': 'h2oiyr244f8vxmibymtzl049qma6w11'
},
Message: { '@type': 'xsd:string', '@value': 'Adding 4 employees' },
'Parent ID': 'terminusdb://ref/data/ValidCommit/trkmri653hdpt8qlarspdfaqw49f5qq',
Time: { '@type': 'xsd:decimal', '@value': 1637908995.4400997 }
},
{
Author: { '@type': 'xsd:string', '@value': 'undefined' },
'Commit ID': {
'@type': 'xsd:string',
'@value': 'trkmri653hdpt8qlarspdfaqw49f5qq'
},
Message: { '@type': 'xsd:string', '@value': 'Inserting schema' },
'Parent ID': null,
Time: { '@type': 'xsd:decimal', '@value': 1637908889.3347943 }
}
]The last change we made was adding Ethan, the contractors have not been added here.
Let's go to the contractors branch:
console.log("Contractors Commit History: ")
await getCommitHistory("contractors");And check the log again:
[
{
Author: { '@type': 'xsd:string', '@value': 'undefined' },
'Commit ID': {
'@type': 'xsd:string',
'@value': 'stjoccbxjgncn53oebgmghnpzirljyo'
},
Message: { '@type': 'xsd:string', '@value': 'Adding contractors' },
'Parent ID': 'terminusdb://ref/data/ValidCommit/2zt3shmtvrrdsk63kvdxiwtzakthwb3',
Time: { '@type': 'xsd:decimal', '@value': 1637910335.5157332 }
},
{
Author: { '@type': 'xsd:string', '@value': 'undefined' },
'Commit ID': {
'@type': 'xsd:string',
'@value': '2zt3shmtvrrdsk63kvdxiwtzakthwb3'
},
Message: { '@type': 'xsd:string', '@value': 'Adding ethan' },
'Parent ID': 'terminusdb://ref/data/ValidCommit/a3ek3oouby4c098t4horxfrsbdgyy2m',
Time: { '@type': 'xsd:decimal', '@value': 1637909051.3614013 }
},
{
Author: { '@type': 'xsd:string', '@value': 'undefined' },
'Commit ID': {
'@type': 'xsd:string',
'@value': 'a3ek3oouby4c098t4horxfrsbdgyy2m'
},
Message: { '@type': 'xsd:string', '@value': 'updating 001' },
'Parent ID': 'terminusdb://ref/data/ValidCommit/h2oiyr244f8vxmibymtzl049qma6w11',
Time: { '@type': 'xsd:decimal', '@value': 1637909050.0255294 }
},
{
Author: { '@type': 'xsd:string', '@value': 'undefined' },
'Commit ID': {
'@type': 'xsd:string',
'@value': 'h2oiyr244f8vxmibymtzl049qma6w11'
},
Message: { '@type': 'xsd:string', '@value': 'Adding 4 employees' },
'Parent ID': 'terminusdb://ref/data/ValidCommit/trkmri653hdpt8qlarspdfaqw49f5qq',
Time: { '@type': 'xsd:decimal', '@value': 1637908995.4400997 }
},
{
Author: { '@type': 'xsd:string', '@value': 'undefined' },
'Commit ID': {
'@type': 'xsd:string',
'@value': 'trkmri653hdpt8qlarspdfaqw49f5qq'
},
Message: { '@type': 'xsd:string', '@value': 'Inserting schema' },
'Parent ID': null,
Time: { '@type': 'xsd:decimal', '@value': 1637908889.3347943 }
}
]We have a new entry for the log.
After the contractors branch is created and data inserted into it. The company managers approve the change. We would now like to incorporate the changes back to the main branch. Those who are familiar with the Git workflow will know that we need to perform a merge from the contractors branch to the main branch. But we are going to do it differently, using rebase instead of merge.
Rebase means that we take the changes since branching the database and will continue from another branch. For example, if we rebase main from contractors we will continue from what contractors is now, i.e. after adding the contractors. This means we have incorporated the change in contractors into main. For more information about rebase have a read of the Git documentation.
To do it, let's go back to main and rebase from contractors:
client.checkout("main");
await client.rebase({rebase_from: `${teamName}/GettingStartedDB/local/branch/contractors/`, message: "Merging from contractors",author: "user"});
When we do getCommitHistory we see that we have the Adding contractors commit in it.
console.log("Main Commit History: ")
await getCommitHistory("main");Time flies, now the project is done and the contractors have left the company. We are going to time travel to the state of the company before the project.
Let's verify our commit history again:
const mainCommits = await getCommitHistory("main");
//from the commit history we get the commit ID that we need
const mainCommitObj = mainCommits.find(item=>item["Message"]["@value"] === 'Adding ethan')
const oldMainCommitID = mainCommitObj['Commit ID']['@value']We would like to keep the commits up to the Adding Ethan one.
To reset, we use the client.resetBranch(branch,commitID) function:
await client.resetBranch("main", oldMainCommitID); IMPORTANT!!!! That it is an hard reset, meaning that the changes after the commit Adding Ethan are gone forever!
Now let's have a look at the log again:
console.log("Main Commit History: ")
await getCommitHistory("main");We are back to where we were again.
Check out the JavaScript Reference Guide for more information about the JS client