1 import
 MerlinDB, {
Schema}
 from 
"@chrisaxxwell/merlin-db";
2 //Or if you are using 'merlindb.min.js' just call 'new MerlinDB()'; 
3 
4 const
 merlin = new
 MerlinDB(
)
;
5 merlin.connect(
"MY-STORE-DATABASE")
;
6 
7 const
 ClientSchema = Schema({ //Or merlin.Schema(<your-Schema>)
8    name:
 {
type:
 String
, unique:
 true
}
,
9    //Or defining a message
10    name:
 {
11       type:
 String
, 
12       unique:
 [true
, "{
VALUE}
" already exists database or any message!]
13    }
14 }
)
;
15 
16 //Your database model looks like this:
17 //model.Clients
18 {
 id_:
 "r4RwerF23W3T...", name:
 "Chris Axxwell" }
,
19 {
 id_:
 "53fE7Sf...", name:
 "Jason Statham" }
,
20 //...

Now you will try to insert a new customer with the name Chris Axxxell, and this document will not be inserted into the model:

1 var
 clientModel = merlin.model(
"Clients", ClientSchema)
;
2 
3 try{
4    await clientModel.insert(
{
5       name:
 "Chris Axxwell"
6    }
)
;
7 }>catch(
err)
{
8    console.log(
err)
;
9    // returns 'Chris Axxwell' name, already exists! 
10 }

⇜ Schema.types Schema.required ⇝

Schema.types Schema.unique Schema.required

1	var clientModel = merlin .model( "Clients", ClientSchema ) ;
2
3	try {
4	await clientModel .insert( {
5	name: "Chris Axxwell"
6	} ) ;
7	}>catch( err ) {
8	console .log( err ) ;
9	// returns 'Chris Axxwell' name, already exists!
10	}

1	import MerlinDB, { Schema } from "@chrisaxxwell/merlin-db";
2	//Or if you are using 'merlindb.min.js' just call 'new MerlinDB()';
3
4	const merlin = new MerlinDB( ) ;
5	merlin .connect( "MY-STORE-DATABASE" ) ;
6
7	const ClientSchema = Schema({ //Or merlin.Schema(<your-Schema>)
8	name: { type: String , unique: true } ,
9	//Or defining a message
10	name: {
11	type: String ,
12	unique: [ true , " { VALUE } " already exists database or any message!]
13	}
14	} ) ;
15
16	//Your database model looks like this:
17	//model.Clients
18	{ id_: "r4RwerF23W3T...", name: "Chris Axxwell" } ,
19	{ id_: "53fE7Sf...", name: "Jason Statham" } ,
20	//...