Local database using browser localStorage api
npm install local-db``
yarn add local-db --dev
or
npm install local-db --save-dev
or Usage
`
import LocalDB from 'local-db'
or
var LocalDB = require('local-db)
then
`
var usersTable = new LocalDB('users')
property, LocalDB will try to update the object in the table with
regarding id.`
usersTable.insert({username:'kucukkanat',city:'Izmir'})
returns : the user object created in table with generated ID$3
Returns an array of the elements matching the query
// Guys you are not allowed to buy cigarettes!
usersTable.query({age:{$lt:{18}}})
returns : the user object created in table with generated ID$3
Updates all objects in table matching the query. The update method does a deep merge
using 's _.merge method. _.merge`
// Moves kucukkanat from Izmir to Amsterdam
usersTable.update({username:'kucukkanat'},{city:'Amsterdam'})
returns : LocalDB instance itself$3
Deletes all objects in table matching the query
// Are you not a bit old for skating grandpa ?
usersTable.delete({age:{$gt:70}})
returns : LocalDB instance itself$3
Empties the table
usersTable.drop()
returns : LocalDB instance itself
$3
Listens for events : , create , update , remove , delete , drop
users.on('$insert',(object)=>{
// console.log(object, ' inserted!')
})
users.on('$delete',(object)=>{
// console.log(object, ' deleted!')
})
users.on('$update',(object,nextObject)=>{
console.log(object, ' updated to ',nextObject)
})
returns : LocalDB instance itselfSupported Operators:
See MongoDB's advanced queries for more info.
$3
array value must be $in the given query:
Intersecting two arrays:
javascript
//filtered: ['Brazil']
table.query({ $in: ['Costa Rica','Brazil'] }, ['Brazil','Haiti','Peru','Chile']);
`Here's another example. This acts more like the $or operator:
javascript
table.query({ location: { $in: ['Costa Rica','Brazil'] } }, [ { name: 'Craig', location: 'Brazil' } ]);
`$3
Opposite of $in:
javascript
//filtered: ['Haiti','Peru','Chile']
table.query({ $nin: ['Costa Rica','Brazil'] }, ['Brazil','Haiti','Peru','Chile']);
`$3
Checks if whether a value exists:
javascript
//filtered: ['Craig','Tim']
table.query({ $exists: true }, ['Craig',null,'Tim']);
`You can also filter out values that don't exist
javascript
//filtered: [{ name: 'Craig', city: 'Minneapolis' }]
table.query({ city: { $exists: false } }, [ { name: 'Craig', city: 'Minneapolis' }, { name: 'Tim' }]);
`$3
Checks if a number is >= value:
javascript
//filtered: [2, 3]
table.query({ $gte: 2 }, [0, 1, 2, 3]);
`$3
Checks if a number is > value:
javascript
//filtered: [3]
table.query({ $gt: 2 }, [0, 1, 2, 3]);
`$3
Checks if a number is <= value.
javascript
//filtered: [0, 1, 2]
table.query({ $lte: 2 }, [0, 1, 2, 3]);
`$3
Checks if number is < value.
javascript
//filtered: [0, 1]
table.query({ $lt: 2 }, [0, 1, 2, 3]);
`$3
Checks if query == value. Note that $eq can be omitted. For $eq, and $ne
javascript
//filtered: [{ state: 'MN' }]
table.query({ state: {$eq: 'MN' }}, [{ state: 'MN' }, { state: 'CA' }, { state: 'WI' }]);
`Or:
javascript
//filtered: [{ state: 'MN' }]
table.query({ state: 'MN' }, [{ state: 'MN' }, { state: 'CA' }, { state: 'WI' }]);
`$3
Checks if query != value.
javascript
//filtered: [{ state: 'CA' }, { state: 'WI'}]
table.query({ state: {$ne: 'MN' }}, [{ state: 'MN' }, { state: 'CA' }, { state: 'WI' }]);
`$3
Modulus:
javascript
//filtered: [300, 600]
table.query({ $mod: [3, 0] }, [100, 200, 300, 400, 500, 600]);
`$3
values must match everything in array:
javascript
//filtered: [ { tags: ['books','programming','travel' ]} ]
table.query({ tags: {$all: ['books','programming'] }}, [
{ tags: ['books','programming','travel' ] },
{ tags: ['travel','cooking'] } ]);
`$3
ability to use an array of expressions. All expressions must test true.
javascript
//filtered: [ { name: 'Craig', state: 'MN' }]table.query({ $and: [ { name: 'Craig' }, { state: 'MN' } ] }, [
{ name: 'Craig', state: 'MN' },
{ name: 'Tim', state: 'MN' },
{ name: 'Joe', state: 'CA' } ]);
`$3
OR array of expressions.
javascript
//filtered: [ { name: 'Craig', state: 'MN' }, { name: 'Tim', state: 'MN' }]
table.query({ $or: [ { name: 'Craig' }, { state: 'MN' } ] }, [
{ name: 'Craig', state: 'MN' },
{ name: 'Tim', state: 'MN' },
{ name: 'Joe', state: 'CA' } ]);
`$3
opposite of or:
javascript
//filtered: [ { name: 'Tim', state: 'MN' }, { name: 'Joe', state: 'CA' }]
table.query({ $nor: [ { name: 'Craig' }, { state: 'MN' } ] }, [
{ name: 'Craig', state: 'MN' },
{ name: 'Tim', state: 'MN' },
{ name: 'Joe', state: 'CA' } ]);
`
$3
Matches an array - must match given size:
javascript
//filtered: ['food','cooking']
table.query({ tags: { $size: 2 } }, [ { tags: ['food','cooking'] }, { tags: ['traveling'] }]);
`$3
Matches a values based on the type
javascript
table.query({ $type: Date }, [new Date(), 4342, 'hello world']); //returns single date
table.query({ $type: String }, [new Date(), 4342, 'hello world']); //returns ['hello world']
`$3
Matches values based on the given regular expression
javascript
table.query({ $regex: /^f/i, $nin: ["frank"] }, ["frank", "fred", "sam", "frost"]); // ["fred", "frost"]
table.query({ $regex: "^f", $options: "i", $nin: ["frank"] }, ["frank", "fred", "sam", "frost"]); // ["fred", "frost"]
`$3
Matches based on some javascript comparison
javascript
table.query({ $where: "this.name === 'frank'" }, [{name:'frank'},{name:'joe'}]); // ["frank"]
table.query({
$where: function() {
return this.name === "frank"
}
}, [{name:'frank'},{name:'joe'}]); // ["frank"]
`$3
Matches elements of array
javascript
var bills = [{
month: 'july',
casts: [{
id: 1,
value: 200
},{
id: 2,
value: 1000
}]
},
{
month: 'august',
casts: [{
id: 3,
value: 1000,
}, {
id: 4,
value: 4000
}]
}];var result = table.query({
casts: {$elemMatch:{
value: {$gt: 1000}
}}
}, bills); // {month:'august', casts:[{id:2, value: 1000},{id: 4, value: 4000}]}
`$3
Not expression:
javascript
table.query({$not:{$in:['craig','tim']}}, ['craig','tim','jake']); //['jake']
table.query({$not:{$size:5}}, ['craig','tim','jake']); //['tim','jake']
`sub object Searching
javascript
var people = [{
name: 'craig',
address: {
city: 'Minneapolis'
}
},
{
name: 'tim',
address: {
city: 'St. Paul'
}
}];var queried = table.query({ address: { city: 'Minneapolis' }}, people); // count = 1
//or
var queried = table.query({'address.city': 'minneapolis'}, people);//count = 1
``