websql-json

Web SQLite access library. Communicate easily and cleanly using JSON objects.

Usage

``js
var local = require('websql-json');
`

Connect:

- Use this method in order to connect to the database

If you call the connect method at the start, you do not need to include the name field on subsequent transactions.

`js
local.connect(data, callback);

var data = {
name: 'database_name',
version: '1.0',
descr: 'database_description',
size: 500000,
};

// or

var data = {
name: 'database_name',
};
`

- The name field is mandatory and must be defined.
- version, descr and size are all optional fields.
- The default value for version is 1.0. It can only be 1.0 or 2.0.
- The default value for descr will be the same as the name of the database.
- The default value for size is 500000. Its maximum value is 52428000.

Create:

- Use this method in order to create a table

`js
local.transaction('create', data, callback);

// The columns field must be an array of strings

var data = {
name: 'database_name',
data: [
{
table: 'table_a',
columns: ['col1', 'col2'],
},
{
table: 'table_b',
columns: ['col3', 'col4'],
},
],
inserts: [
name: 'database_name',
data: [
{
table: 'table_a',
data: {
col1: 'val1',
col2: 'val2',
},
},
{
table: 'table_b',
data: {
col3: 'val3',
col4: 'val4',
},
},
],
],
};
`

Drop:

- Use this method in order to delete a table and all of its contents

`js
local.transaction('drop', data, callback);

var data = {
name: 'database_name',
data: [
{
table: 'table_a',
},
{
table: 'table_b',
},
],
};
`

Insert:

- Use this method to insert data into a table
- Multi-row insertion is also possible

`js
local.transaction('insert', data, callback);

var data = {
name: 'database_name',
data: [
{
table: 'table_a',
data: {
col1: 'val1',
col2: 'val2',
},
},
{
table: 'table_b',
data: {
col3: 'val3',
col4: 'val4',
},
},
],
};

// data must be an array of JSON objects. e.g.

var data = {
name: 'database_name',
data: [
{
table: 'devices',
name: 'device 1',
type: 'ctrl',
},
{
table: 'devices',
name: 'device 2',
type: 'ctrl',
},
],
};
`

Delete:

- Use this method in order to delete data from a table

`js
local.transaction('delete', data, callback);

// Delete data where col1 has a value of val1

var data = {
name: 'database_name',
table: 'table_name',
data: {
col1: 'val1',
},
};

// Or delete all data from the table

var data = {
name: 'database_name',
table: 'table_name',
data: {},
};
`

Update:

- Use this method to update data in a table

`js
local.transaction('update', data, callback);

var data = {
name: 'database_name',
table: 'table_name',
data: {
set: {
col1: 'val1',
col2: 'val2',
},
where: {
col3: 'val3',
col4: 'val4',
},
},
};

// set and where must be JSON objects with one or many key value pairs. e.g.

var data = {
name: 'database_name',
table: 'devices',
data: {
set: {
name: 'new_device',
},
where: {
type: 'ctrl',
mac: 'ff',
},
},
};
`

- This generates the SQL: UPDATE devices SET name='new_device' WHERE type='ctrl' AND mac='ff';
- In this case the set condition is applied to all rows of the table.
- set _cannot be_ empty
- where _can be_ empty

Find:

- Use this method to search a database table for a particular piece of data

`js
local.transaction('find', data, callback);

// Find data where col1 has a value of val1 or val2 or val3 and col2 has a value of val4
// Additionally join on table_b and select all columns from table_b

var data = {
name: 'database_name',
table: 'table_a',
data: {
col1: ['val1', 'val2', 'val3'],
col2: 'val4',
},
join: {
query: 'JOIN table_b on table_a.join_id = table_b.id',
},
selects: 'table_b.*',
groupBy: 'join_id',
orderBy: [
'join_id',
'another_column',
],
};

// Or find and return all data from table_a

var data = {
name: 'database_name',
table: 'table_a',
data: {},
};
`

---

Result

- The result of all the methods will be a JSON object

`js
var callbackData = {
// Returned from a CREATE transaction when additional INSERT data is provided
// This allows an INSERT transaction to proceed directly after a CREATE
callbackData: { data: [], name: 'database_name' },

done: flag,
message: message,
queryType: queryType,

// Returned from a FIND transaction as an SQLResultSetRowList
rows: [],
};
`

- done returns true if the database call is successful, or false if it is not
- queryType returns the type of query that was executed (e.g. "create", "insert", etc.)
- message returns a success or failure string (e.g. "Table created successfully")
- In case of a FIND transaction the result is returned under a rows` object key