Chapter 29. libpq - C Library

Table of Contents

29.1. Introduction

29.2. Using libpq with EnterpriseDB SPL

29.3. libpq EnterpriseDB API

29.3.1. Preparing a Callable Statement
29.3.2. Executing a Callable Statement
29.3.3. Fetching Cursors from a Result Set
29.3.4. Returning the Number of Cursors Fetched from a Result Set
29.3.5. Retrieving the Out Parameter from the Result
29.3.6. Cursor Support Statements in EnterpriseDB

29.4. libpq Concepts

29.4.1. Database Connection Control Functions
29.4.2. Connection Status Functions
29.4.3. Command Execution Functions
29.4.4. Asynchronous Command Processing
29.4.5. Cancelling Queries in Progress
29.4.6. The Fast-Path Interface
29.4.7. Asynchronous Notification
29.4.8. Functions Associated with the COPY Command
29.4.9. Control Functions
29.4.10. Notice Processing
29.4.11. Environment Variables
29.4.12. The Password File
29.4.13. The Connection Service File
29.4.14. Behavior in Threaded Programs

29.5. Client Interfaces

29.5.1. What are Large Objects?
29.5.2. Creating a Large Object
29.5.3. Importing a Large Object
29.5.4. Exporting a Large Object
29.5.5. Opening an Existing Large Object
29.5.6. Writing Data to a Large Object
29.5.7. Reading Data from a Large Object
29.5.8. Seeking in a Large Object
29.5.9. Obtaining the Seek Position of a Large Object
29.5.10. Closing a Large Object Descriptor
29.5.11. Removing a Large Object

29.6. Usage and Example

29.6.1. Example
29.6.2. Output

29.1. Introduction

libpq is the C application programmer's interface (API) to EnterpriseDB. libpq is a set of library functions that allow client programs to pass queries to the EnterpriseDB backend server and to receive the results of these queries.

libpq is also the underlying engine for several other EnterpriseDB application interfaces, including those written for C++, Perl, Python, Tcl and ECPG. So some aspects of libpq's behavior will be important to the user if one of those packages is used.

Client programs that use libpq must include the header file libpq-fe.h and must link with the libpq library.