Crane is a query builder for React Native extracted from Laravel's illuminate/database. This library supports both react-native-sqlite-storage and expo sqlite.
For a demo, click here.
Crane requires SQLite driver in order to work.
If you are using expo, install the expo-sqlite
expo install expo-sqlite
If you are using bare React Native, install the react-native-sqlite-storage
. For detail instruction, please refer to the package documentation
yarn add react-native-sqlite-storage
Finally, install crane
yarn add crane-query-builder
import React, { useEffect } from 'react';
import { StyleSheet, Text, View } from 'react-native';
import { Asset } from 'expo-asset';
import * as SQLite from 'expo-sqlite';
import * as FileSystem from 'expo-file-system';
import Builder, { DB } from 'crane'; // Import the library
export default function App() {
useEffect(() => {
testDB();
}, []);
return (
<View style={styles.container}>
<Text>Open up App.js to start working on your app!</Text>
</View>
);
}
export async function testDB() {
await initDB();
await getAlbums();
}
export async function initDB() {
await testDriver();
await loadDB();
}
export async function testDriver() {
const dummy = SQLite.openDatabase('dummy.db');
try {
await dummy.transaction(tx => tx.executeSql(''));
} catch (e) {
if (this.state.debugEnabled)
console.log('error while executing SQL in dummy DB');
}
}
export async function loadDB() {
let dbFile = await FileSystem.getInfoAsync(`${FileSystem.documentDirectory}SQLite/db.db`);
if (!dbFile.exists)
makeDir();
// Add connection using DB.addConnection
DB.addConnection({
type: 'expo',
driver: SQLite,
name: 'db.db',
});
}
export async function makeDir() {
await FileSystem.downloadAsync(
Asset.fromModule(require('./assets/db/db.db')).uri,
`${FileSystem.documentDirectory}SQLite/db.db`
);
}
export async function getAlbums() {
// Build your query
let albums = await Builder()
.table('albums')
.where('ArtistId', '>', 200)
.get();
console.log(albums);
}
const styles = StyleSheet.create({
container: {
flex: 1,
backgroundColor: '#fff',
alignItems: 'center',
justifyContent: 'center',
},
});
// doc coming soon...
- Retrieving Results
- Selects
- Raw Expressions
- Joins
- Unions
- Where Clauses
- Ordering, Grouping, Limit & Offset
- Inserts
- Updates
- Deletes
Retrieving All Rows From A Table
You may use the table
method begin a query. The table method returns a fluent query builder instance for the given table, allowing you to chain more constraints onto the query and then finally get the results using the get
method:
let albums = await Builder()
.table('albums')
.get()
Retrieving A Single Row / Column From A Table
If you just need to retrieve a single row from the database table, you may use the first
method.
let albums = await Builder()
.table('albums')
.where('ArtistId', '>', 200)
.first()
If you don't even need an entire row, you may extract a single value from a record using the value method. This method will return the value of the column directly:
let employees = await Builder()
.table('employees')
.where('Title', 'Sales Support Agent')
.value('FirstName')
To retrieve a single row by its id
column value, use the find
method:
let users = await Builder()
.table('users')
.find(4)
Retrieving A List Of Column Values
If you would like to retrieve a Collection containing the values of a single column, you may use the pluck
method. In this example, we'll retrieve a Collection of role titles:
let employees = await Builder()
.table('employees')
.where('Title', 'Sales Support Agent')
.pluck('FirstName', 'LastName')
The query builder also provides a variety of aggregate methods such as count, max
, min
, avg
, and sum
. You may call any of these methods after constructing your query:
let customers = await Builder()
.table('customers')
.count()
let invoices = await Builder()
.table('invoices')
.max('total')
You may combine these methods with other clauses:
let invoices = await Builder()
.table('invoices')
.where('BillingState', 'CA')
.avg('total')
Determining If Records Exist
Instead of using the count
method to determine if any records exist that match your query's constraints, you may use the exists
and doesntExist
methods:
let customersA = await Builder()
.table('customers')
.where('PostalCode', '14700')
.exists()
let customersB = await Builder()
.table('customers')
.where('PostalCode', '14700')
.doesntExist()
Specifying A Select Clause
You may not always want to select all columns from a database table. Using the select
method, you can specify a custom select
clause for the query:
let customers = await Builder()
.table('customers')
.select('FirstName', 'Phone as CustomerPhone')
.get()
The distinct
method allows you to force the query to return distinct results:
let customers = await Builder()
.table('customers')
.distinct()
.get()
If you already have a query builder instance and you wish to add a column to its existing select clause, you may use the addSelect
method:
let query = Builder()
.table('customers')
.select('FirstName')
let customers = await query
.addSelect('LastName')
.get()
Sometimes you may need to use a raw expression in a query. To create a raw expression, you may use the raw
method:
let users = await Builder().table('users')
.select(Builder().raw('count(*) as user_count, status'))
.where('status', '<>', 1)
.groupBy('status')
.get()
Raw statements will be injected into the query as strings, so you should be extremely careful to not create SQL injection vulnerabilities.
Instead of using raw
, you may also use the following methods to insert a raw expression into various parts of your query.
selectRaw
The selectRaw method can be used in place of addSelect(Builder().raw(...))
. This method accepts an optional array of bindings as its second argument:
let orders = await Builder()
.table('orders')
.selectRaw('price * ? as price_with_tax', [1.0825])
.get()
whereRaw / orWhereRaw
The whereRaw
and orWhereRaw
methods can be used to inject a raw where clause into your query. These methods accept an optional array of bindings as their second argument:
let orders = await Builder()
.table('orders')
.whereRaw('price > IF(state = "TX", ?, 100)', [200])
.get()
havingRaw / orHavingRaw
The havingRaw
and orHavingRaw
methods may be used to set a raw string as the value of the having
clause. These methods accept an optional array of bindings as their second argument:
let orders = await Builder()
.table('orders')
.select('department', Builder().raw('SUM(price) as total_sales'))
.groupBy('department')
.havingRaw('SUM(price) > ?', [2500])
.get()
orderByRaw
The orderByRaw
method may be used to set a raw string as the value of the order by
clause:
let orders = await Builder()
.table('orders')
.orderByRaw('updated_at - created_at DESC')
.get()
Inner Join Clause
The query builder may also be used to write join statements. To perform a basic "inner join", you may use the join
method on a query builder instance. The first argument passed to the join
method is the name of the table you need to join to, while the remaining arguments specify the column constraints for the join. You can even join to multiple tables in a single query:
let users = await Builder()
.table('users')
.join('contacts', 'users.id', '=', 'contacts.user_id')
.join('orders', 'users.id', '=', 'orders.user_id')
.select('users.*', 'contacts.phone', 'orders.price')
.get()
Left Join / Right Join Clause
If you would like to perform a "left join" or "right join" instead of an "inner join", use the leftJoin
or rightJoin
methods. These methods have the same signature as the join
method:
let usersA = await Builder()
.table('users')
.leftJoin('posts', 'users.id', '=', 'posts.user_id')
.get()
let usersB = await Builder()
.table('users')
.rightJoin('posts', 'users.id', '=', 'posts.user_id')
.get()
Cross Join Clause
To perform a "cross join" use the crossJoin
method with the name of the table you wish to cross join to. Cross joins generate a cartesian product between the first table and the joined table:
let users = await Builder()
.table('sizes')
.crossJoin('colours')
.get()
Advanced Join Clauses
You may also specify more advanced join clauses. To get started, pass a Closure
as the second argument into the join
method. The Closure
will receive a JoinClause
object which allows you to specify constraints on the join
clause:
await Builder()
.table('users')
.join('contacts', join => {
join
.on('users.id', '=', 'contacts.user_id')
.orOn(...)
})
.get()
If you would like to use a "where" style clause on your joins, you may use the where
and orWhere
methods on a join. Instead of comparing two columns, these methods will compare the column against a value:
await Builder()
.table('users')
.join('contacts', join => {
join
.on('users.id', '=', 'contacts.user_id')
.where('contacts.user_id', '>', 5)
})
.get()
Subquery Joins
You may use the joinSub
, leftJoinSub
, and rightJoinSub
methods to join a query to a subquery. Each of these methods receive three arguments: the subquery, its table alias, and a Closure that defines the related columns:
await Builder()
.table('users')
.join('contacts', join => {
join
.on('users.id', '=', 'contacts.user_id')
.where('contacts.user_id', '>', 5);
})
.get()
The query builder also provides a quick way to "union" two queries together. For example, you may create an initial query and use the union
method to union it with a second query:
let first = await Builder()
.table('users')
.whereNull('first_name')
let users = await Builder()
.table('users')
.whereNull('last_name')
.union(first)
.get()
The
unionAll
method is also available and has the same method signature asunion
.
Simple Where Clauses
You may use the where
method on a query builder instance to add where
clauses to the query. The most basic call to where
requires three arguments. The first argument is the name of the column. The second argument is an operator, which can be any of the database's supported operators. Finally, the third argument is the value to evaluate against the column.
For example, here is a query that verifies the value of the "votes" column is equal to 100:
let users = await Builder()
.table('users')
.where('votes', '=', 100)
.get()
For convenience, if you want to verify that a column is equal to a given value, you may pass the value directly as the second argument to the where
method:
let users = await Builder()
.table('users')
.where('votes', 100)
.get()
You may use a variety of other operators when writing a where
clause:
let usersA = await Builder()
.table('users')
.where('votes', '>=', 100)
.get()
let usersB = await Builder()
.table('users')
.where('votes', '<>', 100)
.get()
let usersC = await Builder()
.table('users')
.where('name', 'like', 'T%')
.get()
You may also pass an array of conditions to the where
function:
let users = await Builder()
.table('users')
.where([
['status', '=', '1'],
['subscribed', '<>', '1'],
])
.get()
Or Statements
You may chain where constraints together as well as add or clauses to the query. The orWhere
method accepts the same arguments as the where
method:
let users = await Builder()
.table('users')
.where('votes', '>', 100)
.orWhere('name', 'John')
.get()
Additional Where Clauses
whereBetween / orWhereBetween
The whereBetween
method verifies that a column's value is between two values:
let users = await Builder()
.table('users')
.whereBetween('votes', [1, 100])
.get()
whereNotBetween / orWhereNotBetween
The whereNotBetween
method verifies that a column's value lies outside of two values:
let users = await Builder()
.table('users')
.whereNotBetween('votes', [1, 100])
.get()
whereIn / whereNotIn / orWhereIn / orWhereNotIn
The whereIn
method verifies that a given column's value is contained within the given array:
let users = await Builder()
.table('users')
.whereIn('id', [1, 2, 3])
.get()
The whereNotIn
method verifies that the given column's value is not contained in the given array:
let users = await Builder()
.table('users')
.whereNotIn('id', [1, 2, 3])
.get()
whereNull / whereNotNull / orWhereNull / orWhereNotNull
The whereNull
method verifies that the value of the given column is NULL
:
let users = await Builder()
.table('users')
.whereNull('updated_at')
.get()
The whereNotNull
method verifies that the column's value is not NULL
:
let users = await Builder()
.table('users')
.whereNotNull('updated_at')
.get()
whereDate / whereMonth / whereDay / whereYear / whereTime
The whereDate
method may be used to compare a column's value against a date:
let users = await Builder()
.table('users')
.whereDate('created_at', '2016-12-31')
.get()
The whereMonth
method may be used to compare a column's value against a specific month of a year:
let users = await Builder()
.table('users')
.whereMonth('created_at', '12')
.get()
The whereDay
method may be used to compare a column's value against a specific day of a month:
let users = await Builder()
.table('users')
.whereDay('created_at', '31')
.get()
The whereYear
method may be used to compare a column's value against a specific year:
let users = await Builder()
.table('users')
.whereYear('created_at', '2016')
.get()
The whereTime
method may be used to compare a column's value against a specific time:
let users = await Builder()
.table('users')
.whereTime('created_at', '=', '11:20:45')
.get()
whereColumn / orWhereColumn
The whereColumn
method may be used to verify that two columns are equal:
let users = await Builder()
.table('users')
.whereColumn('first_name', 'last_name')
.get()
You may also pass a comparison operator to the method:
let users = await Builder()
.table('users')
.whereColumn('updated_at', '>', 'created_at')
.get()
The whereColumn
method can also be passed an array of multiple conditions. These conditions will be joined using the and operator:
let users = await Builder()
.table('users')
.whereColumn([
['first_name', '=', 'last_name'],
['updated_at', '>', 'created_at'],
])
.get()
Sometimes you may need to create more advanced where clauses such as "where exists" clauses or nested parameter groupings. The Laravel query builder can handle these as well. To get started, let's look at an example of grouping constraints within parenthesis:
let users = await Builder()
.table('users')
.where('name', '=', 'John')
.where(query => {
query
.where('votes', '>', 100)
.orWhere('title', '=', 'Admin')
})
.get()
As you can see, passing a Closure
into the where
method instructs the query builder to begin a constraint group. The Closure
will receive a query builder instance which you can use to set the constraints that should be contained within the parenthesis group. The example above will produce the following SQL:
select * from users where name = 'John' and (votes > 100 or title = 'Admin')
You should always group
orWhere
calls in order to avoid unexpected behavior when global scopes are applied.
orderBy
The orderBy
method allows you to sort the result of the query by a given column. The first argument to the orderBy
method should be the column you wish to sort by, while the second argument controls the direction of the sort and may be either asc
or desc
:
let users = await Builder()
.table('users')
.orderBy('name', 'desc')
.get()
latest / oldest
The latest
and oldest
methods allow you to easily order results by date. By default, result will be ordered by the created_at
column. Or, you may pass the column name that you wish to sort by:
let users = await Builder()
.table('users')
.latest()
.first()
inRandomOrder
The inRandomOrder
method may be used to sort the query results randomly. For example, you may use this method to fetch a random user:
let users = await Builder()
.table('users')
.inRandomOrder()
.first()
groupBy / having
The groupBy
and having
methods may be used to group the query results. The having method's signature is similar to that of the where method:
let users = await Builder()
.table('users')
.groupBy('account_id')
.having('account_id', '>', 100)
.get()
You may pass multiple arguments to the groupBy
method to group by multiple columns:
let users = await Builder()
.table('users')
.groupBy('first_name', 'status')
.having('account_id', '>', 100)
.get()
For more advanced having
statements, see the havingRaw
method.
skip / take
To limit the number of results returned from the query, or to skip a given number of results in the query, you may use the skip
and take
methods:
let users = await Builder()
.table('users')
.skip(10)
.take(5)
.get()
Alternatively, you may use the limit
and offset
methods:
let users = await Builder()
.table('users')
.offset(10)
.limit(5)
.get()
The query builder also provides an insert
method for inserting records into the database table. The insert
method accepts an array of column names and values:
let users = await Builder()
.table('artists')
.insert({
ArtistId: 500,
Name: 'Euismod Pellentesque'
})
You may even insert several records into the table with a single call to insert
by passing an array of arrays. Each array represents a row to be inserted into the table:
let users = await Builder()
.table('artists')
.insert([
{
ArtistId: 501,
Name: 'Venenatis Elit'
},
{
ArtistId: 502,
Name: 'Justo Pellentesque'
},
])
The insertOrIgnore
method will ignore duplicate record errors while inserting records into the database:
let users = await Builder()
.table('artists')
.insertOrIgnore([
{
ArtistId: 501,
Name: 'Venenatis Elit'
},
{
ArtistId: 502,
Name: 'Justo Pellentesque'
},
])
Auto-Incrementing IDs
If the table has an auto-incrementing id, use the insertGetId
method to insert a record and then retrieve the ID:
let users = await Builder()
.table('artists')
.insertGetId({
ArtistId: 503,
Name: 'Egestas Inceptos'
})
In addition to inserting records into the database, the query builder can also update existing records using the update
method. The update
method, like the insert
method, accepts an array of column and value pairs containing the columns to be updated. You may constrain the update
query using where
clauses:
let artists = await Builder()
.table('artists')
.table('artists')
.where('ArtistId', 1)
.update({
Name: 'John Doe'
})
Update Or Insert
Sometimes you may want to update an existing record in the database or create it if no matching record exists. In this scenario, the updateOrInsert
method may be used. The updateOrInsert
method accepts two arguments: an array of conditions by which to find the record, and an array of column and value pairs containing the columns to be updated.
The updateOrInsert
method will first attempt to locate a matching database record using the first argument's column and value pairs. If the record exists, it will be updated with the values in the second argument. If the record can not be found, a new record will be inserted with the merged attributes of both arguments:
let artists = await Builder()
.table('artists')
.updateOrInsert(
{
ArtistId: 506
},
{
Name: 'Polymer'
}
)
The query builder also provides convenient methods for incrementing or decrementing the value of a given column. This is a shortcut, providing a more expressive and terse interface compared to manually writing the update
statement.
Both of these methods accept at least one argument: the column to modify. A second argument may optionally be passed to control the amount by which the column should be incremented or decremented:
let artistsA = await Builder()
.table('artists')
.increment('votes')
let artistsB = await Builder()
.table('artists')
.increment('votes', 5)
let artistsC = await Builder()
.table('artists')
.decrement('votes')
let artistsD = await Builder()
.table('artists')
.decrement('votes', 5)
You may also specify additional columns to update during the operation:
let artists = await Builder()
.table('artists')
.increment('votes', 1, {name: 'John'})
The query builder may also be used to delete records from the table via the delete
method. You may constrain delete
statements by adding where
clauses before calling the delete
method:
await Builder()
.table('artists')
.delete()
await Builder()
.table('artists')
.where('ArtistId', 505)
.delete()
If you wish to truncate the entire table, which will remove all rows and reset the auto-incrementing ID to zero, you may use the truncate
method:
await Builder()
.table('artists')
.truncate()
Crane is platform-agnostic, which means it can be used for a web app, and it can be extended for other drivers like PostgreSQL or MySQL by adding Grammar and Connection.
We appreciate feedback and contribution to this repo! Before you get started, please see the following:
- Laravel as the primary reference of this library