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QNX Software Development Platform
QNX SDP is a cross-compiling and debugging environment, including an IDE and command-line tools, for building binary images and programs for target boards running QNX Neutrino 7.1.
OS Components & Operations
QDB Developer's Guide
QDB SQL Reference
QDB supports a subset of ANSI SQL-92.
Statements
QDB recognizes more than 20 types of SQL statements that create, modify, and delete tables, indexes, and triggers, and perform specialized tasks such as database cleanup.
EXPLAIN
Report virtual machine instructions for a command

QNX Momentics IDE User's Guide
This User's Guide describes version 7.1 of the Integrated Development Environment (IDE) that's part of the QNX Momentics tool suite.
QNX Software Development Platform
QNX SDP is a cross-compiling and debugging environment, including an IDE and command-line tools, for building binary images and programs for target boards running QNX Neutrino 7.1.
- Quickstart Guide
- OS Components & Operations
  - Adaptive Partitioning User's Guide
  - Boot Optimization Guide
    The Boot Optimization Guide describes techniques you can use to reduce the time from your board's initial power on until you have a fully functional QNX system running on the board.
  - Building Embedded Systems
    The Building Embedded Systems guide is intended for developers who are developing or building BSPs for QNX Neutrino RTOS embedded systems.
  - Core Networking Stack User's Guide
    This guide introduces you to the QNX Neutrino Core Networking stack and its manager, io-pkt.
  - Customizing a BSP
    While QNX provides Board Support Packages (BSPs) for many common platforms and their individual variants, in some cases, you need a BSP for a board that QNX does not provide. If this is the case, you can modify a QNX BSP or develop your own.
  - Device Publishers Developer's Guide
  - High Availability Framework Developer's Guide
  - High-Performance Networking Stack (io-sock) User's Guide
    This guide contains instructions for implementing and using the QNX Neutrino High-Performance Networking Stack and its manager, io-sock.
  - Instant Device Activation
  - Migrating to QNX SDP 7.1
  - PCI Server User's Guide
  - Persistent Publish/Subscribe Developer's Guide
  - Platform-independent Publish/Subscribe Developer's Guide
    This guide is intended for application developers who want to use the Platform-independent Publish Subscribe (PiPS) framework to exchange information with other applications. First, the overall PiPS design and data-exchange model are explained. Then, tutorials on using PiPS are given. These tutorials cover key tasks such as selecting a publish-subscribe provider to use and writing plugins that read and write custom data types.
  - QDB Developer's Guide
    - Getting Started with QDB
      The QNX Database (QDB) server is a small-footprint, embeddable SQL database server. It is designed as an easy-to-configure QNX Neutrino resource manager.
    - QDB Command Line
      Configure and maintain QDB databases
    - QDB Client
      Execute SQL statements on QDB databases
    - QDB Application Example
      QDB provides methods for client applications to query a database and step through the query results. The sample program shown here provides a walkthrough of the sequence of QDB method calls necessary to connect to a QDB database, issue a query, read the data in the result set, and disconnect from the database.
    - Datatypes in QDB
      QDB databases, which are stored in SQLite files, allow any value stored in any database field to have one of five standard storage classes. The SQLite design doesn't enforce data typing on database columns but instead maps each input value to a storage class based on the column's type affinity (preference).
    - QDB Virtual Machine Opcodes
      QDB uses a virtual machine to execute SQL statements. You can configure QDB to list the opcodes of the programs generated to execute the SQL statements and you can trace program execution.
    - Writing User-Defined Functions
      QDB allows you to write your own functions for manipulating data. The QDB library includes several data structures and functions useful for defining custom functionality, while the SQLite API provides methods that your custom code can call to access arguments or set results.
    - QDB API Reference
      QDB provides a comprehensive API for managing databases and accessing data.
    - QDB SQL Reference
      QDB supports a subset of ANSI SQL-92.
      - Row ID and Autoincrement
        In QDB, every row of every table has a 64-bit signed integer row ID. This ID is unique for each row among all rows in the same table. You can prevent row IDs from ever being reused in a table by using the AUTOINCREMENT keyword.
      - Comments
        Comments make your SQL queries easier to read and understand.
      - Expressions
        SQL expressions are subcomponents of commands. Expressions combine one or more values, operators, and SQL functions to produce a result that can be used in the enclosing command.
      - Keywords
        QDB recognizes more than 100 SQL keywords related to command names, operators, sorting directives, and table, column, and query constraints. You must use special syntax to use keywords as names of program objects.
      - Statements
        QDB recognizes more than 20 types of SQL statements that create, modify, and delete tables, indexes, and triggers, and perform specialized tasks such as database cleanup.
        ALTER TABLE
        Rename or add a new column to an existing table
        ANALYZE
        Analyze indexes to optimize queries
        ATTACH DATABASE
        Attach a database file to the current connection
        CREATE INDEX
        Create an index
        CREATE TABLE
        Create a table
        CREATE TRIGGER
        Create a trigger
        CREATE VIEW
        Create a view
        DELETE
        Remove records from a table
        DETACH DATABASE
        Detach a database file from the current connection
        DROP INDEX
        Remove an index
        DROP TABLE
        Remove a table
        DROP TRIGGER
        Remove a trigger
        DROP VIEW
        Remove a view
        EXPLAIN
        Report virtual machine instructions for a command
        INSERT
        Insert records into a table
        ON CONFLICT
        Deal with a conflict
        PRAGMA
        Modify or query the QDB library
        REINDEX
        Recreate indexes from scratch
        REPLACE
        Alias for INSERT OR REPLACE
        SELECT
        Query a database
        TRANSACTION
        Manually start, end, commit, or roll back a transaction
        UPDATE
        Change the value of columns
        VACUUM
        Clean the main database file
    - fileset Reference
      Copy a file set
  - QNX Helpers Developer's Guide
    These libraries provide QNX helpers, including helpers that assist with logging, string conversion, and number and type sizes.
  - SMMUMAN User's Guide
  - System Analysis Toolkit (SAT) User's Guide
  - System Architecture
    The System Architecture guide accompanies the QNX Neutrino RTOS and is intended for both application developers and end-users.
  - Technotes
  - User's Guide
    The QNX Neutrino User's Guide is intended for all users of a QNX Neutrino RTOS system, from system administrators to end users.
- Audio & Graphics API
- Multimedia
- Networking Middleware
- Programming
- Sensor Framework
- System Security Guide
  The QNX System Security Guide is intended for both system integrators who are responsible for the security of a QNX Neutrino RTOS system and developers who want to create a QNX Neutrino resource manager free from vulnerabilities.
- Utilities & Libraries
QNX Hypervisor
The QNX Hypervisor allows you to run multiple OSs on a target system so you can separate critical and non-critical functions, support a wide variety of applications, and reduce hardware costs.
QNX Software in the Cloud
QNX Software in the Cloud enables developers to use the QNX software in Amazon Web Services (AWS) and Microsoft Azure (Azure).
QNX Advanced Virtualization Frameworks User's Guide
This User's Guide is aimed at all systems integrators and developers who want to design and build embedded systems using the QNX Advanced Virtualization Frameworks.
Typographical Conventions, Support, and Licensing
This section describes the typographical conventions used throughout the documentation and explains how to obtain technical support.

EXPLAIN

Report virtual machine instructions for a command

Synopsis:

 EXPLAIN sql-statement

Description:

The EXPLAIN command modifier is a non-standard QDB extension. The idea comes from a similar command found in PostgreSQL, but the operation is completely different.

If the EXPLAIN keyword appears before any other QDB SQL command, then instead of actually executing the command, the QDB library reports the sequence of virtual machine (VM) instructions it would have used to execute the command had the EXPLAIN keyword not been present. This is useful for performance analysis.

For information about VM instructions, see the documentation on QDB opcodes.

Page updated: March 12, 2026