jsonstor-excel

Home: http://jsonstor.liquicode.com

Version: 0.2.0

Documents are stored in an Excel spreadsheet file.

Overview

jsonstor defines one interface for working with a document store and implements it for a variety of database products and file formats. The interface is the same whichever adapter is underneath, so the storage a project uses becomes a configuration decision rather than a structural one.

This package is one such adapter. Documents are stored in an Excel spreadsheet file.

It is packaged separately so that it stays optional. A project which does not store documents this way never downloads xlsx.

See @liquicode/jsonstor for the interface, and jsonstor.liquicode.com for the documentation.

Getting Started

npm install --save @liquicode/jsonstor-excel

const jsonstor = require( '@liquicode/jsonstor' )();
jsonstor.LoadPlugin( require( '@liquicode/jsonstor-excel' ) );

let storage = jsonstor.GetStorage( 'jsonstor-excel', {
	Path: '...',
	SheetName: '...',
	AutoFlush: true,
	PrimaryKey: "_id",
	PrimaryKeyMutable: false,
	HostIndex: false,
} );

Settings

| Setting | Required | Default | Description | |---|:---:|:---:|---| | Path | Yes | - | Path to the Excel or CSV file storing the data. | | SheetName | Yes | - | The name of the worksheet storing the data. | | AutoFlush | No | true | Write the workbook on every insert, update, replace, and delete. | | PrimaryKey | No | "_id" | The field which holds the identifier. Set it to the key field of an existing store. | | PrimaryKeyMutable | No | false | Allow an update or replacement to change the identifier. When false, such an operation is refused. | | HostIndex | No | false | Keep an index of identifiers, so a search by identifier does not read the whole collection. If something else writes the store, call RefreshIndex(). |

Peculiarities

• A document is a row. The first row of the worksheet holds the field names, and each document is a row below it. A field no earlier document had adds a column.
• The whole worksheet is kept in memory, as in jsonstor-jsonfile, and the workbook is rewritten on each write, or on FlushStorage() with AutoFlush: false.
• An object or array is stored as JSON text in its cell, and read back as the object or array.
• A field holding null reads back absent, because an empty cell cannot tell the two apart.
• A Path ending in .csv is written as CSV, which holds one worksheet.
• Use it to share a collection with someone who works in Excel.

Storage Interface

Every adapter implements the same functions, and they are documented once: Storage Interface.

The operator list is not repeated here. A criteria, a projection, and an update are the engine's, and the list changes whenever the engine gains an operator - a copy in this file could only ever be out of date. See the Operator Reference.

Dependencies

• xlsx : The SheetJS spreadsheet reader and writer.
• @liquicode/jsonstor : The storage interface.
• @liquicode/jsongin : The query engine.

License

MIT