db-meta

Relational database metadata extraction library

The following databases are currently supported:

• SQLite3 - via: node-sqlite3
• MySQL - via: node-mysql
• PostgreSQL - via: node-postgres

Installation

$ npm install db-meta

You'll also need to install the appropriate driver for the database you want to use db-meta with. None are installed by default.

# PostgreSQL
$ npm install pg

# MySQL
$ npm install mysql

# SQLite3
$ npm install sqlite3

Example Usage

var dbmeta = require('db-meta');

dbmeta('pg', { database: 'test' }, function(meta) {
  meta.getVersion(function(err, version) {
    console.log('postgres version is ' + version);
  });

  meta.getTables(function(tables) {
    tables.forEach(function(table) {
      console.log('table name is ' + table.getName());
    });
  });

  meta.getColumns('tablename', function(columns) {
    columns.forEach(function(column) {
      console.log('column name is ' + column.getName());
      console.log('column data type is ' + column.getDataType());
      console.log('column is nullable? ' + column.isNullable());
      console.log('column max length is ' + column.getMaxLength());
    });
  });
});

API

require('db-meta')(driver, options, callback)

Creates a connection to the database using the specified driver. The options object is passed to the specified driver object.

Arguments

• driver - the name of the db-meta driver to use
• options - an options object passed to the db-meta driver to use when connecting to the database
• callback(err, driver) - callback that will be invoked after connecting to the database

The user may pass a connection object in the options argument using the key connection. If this key is included in the options object, the driver will attempt to use the existing connection.

driver.getVersion(callback)

Get the version of the connected database

Arguments

• callback(err, version) - callback invoked with the version information

driver.getTables(callback)

Get an array of table objects representing all user tables in the database

Arguments

• callback(err, tables) - callback invoked with an array of tables. See the table API below for details on the methods available on table objects

Table.getName()

Returns the table's name

driver.getColumns(callback)

Get an array of column objects representing all user columns in the database

Arguments

• callback(err, columns) - callback invoked with an array of columns. See the column API below for details on the methods available on column objects

Column.getName()

Returns the columns name

Column.isNullable()

Returns true if the column is nullable, false otherwise

Column.getDataType()

Returns the data type of the column. See lib/data-type.js for a list of valid data types

Column.getMaxLength()

Returns the max length of the column, if constrained. Only valid for textual columns.

Column.isPrimaryKey()

Returns true if the column is the primary key, false otherwise

Column.getDefaultValue()

Returns the default value for the column

Testing

To run the tests you'll need a local installation of PostgreSQL, MySQL, and SQLite3 with default user accounts. You'll also need to create a schema named db_meta_test beforehand (excluding SQLite3) and install the npm dev dependencies. Finally, you can run all the tests with

$ npm test

License

(The MIT License)

Copyright (c) 2013 Jeff Kunkle

Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.