# Then add one of the following (adding a -save) flag:
The primary target environment for Knex is Node.js, you will need to install the knex library, and then install the appropriate database library: pg for PostgreSQL, CockroachDB and Amazon Redshift, pg-native for PostgreSQL with native C++ libpq bindings (requires PostgresSQL installed to link against), mysql for MySQL or MariaDB, sqlite3 for SQLite3, or tedious for MSSQL. The browser builds outside of WebSQL are primarily for learning purposes - for example, you can pop open the console and build queries on this page using the knex object. Composing SQL queries in the browser for execution on the server is highly discouraged, as this can be the cause of serious security vulnerabilities.
Knex can be used as an SQL query builder in both Node.JS and the browser, limited to WebSQL's constraints (like the inability to drop tables or read schemas). Special thanks to Taylor Otwell and his work on the Laravel Query Builder, from which much of the builder's code and syntax was originally derived. You can report bugs and discuss features on the GitHub issues page, add pages to the wiki or send tweets to to all of the great contributions to the project. Knex is available for use under the MIT software license. The project is hosted on GitHub, and has a comprehensive test suite. It features both traditional node style callbacks as well as a promise interface for cleaner async flow control, a stream interface, full-featured query and schema builders, transaction support (with savepoints), connection pooling and standardized responses between different query clients and dialects. Knex.js (pronounced /kəˈnɛks/) is a "batteries included" SQL query builder for PostgreSQL, CockroachDB, MSSQL, MySQL, MariaDB, SQLite3, Oracle, and Amazon Redshift designed to be flexible, portable, and fun to use.