websql-json

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

Usage

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.

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

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

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

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

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

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

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.*',
    orderBy: ['join_id'],
};
 
// 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

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