Solution to PHP Fatal error: Call to undefined function pg_query()

PHP is a very popular programming language with a wide range of application scenarios. When doing web development, sometimes we need to use PostgreSQL as the database, and the error message "PHP Fatal error: Call to undefined function pg_query()" appears. This is because PHP does not load the function library required by PostgreSQL, resulting in the corresponding error message. The function cannot be executed normally. In this article, we’ll cover some common causes of this error and how to fix it.

1. PHP does not have the necessary extensions installed

The easiest way to solve this problem is to confirm whether your PHP has the PostgreSQL driver installed. If not, you need to recompile it. PHP, specify the PostgreSQL driver, and reinstall it. When compiling PHP, you can add the following configuration options:

--with-pgsql=/path/to/pgsql

where /path/to/pgsql is the path to the PostgreSQL installation directory.

2. The library required by PostgreSQL is not loaded

If you have confirmed that PHP has installed the PostgreSQL driver, but "PHP Fatal error: Call to undefined" still appears function pg_query()" error message, then it is likely that the required library file is not loaded. You can follow the following steps to solve the problem:

(1) Open the php.ini file, uncomment the following two lines, and make sure the path is correct:

extension_dir = "ext"
extension=php_pgsql.dll

(2) If your system If you are using a UNIX-like system such as Linux or Unix, you need to modify the following content:

; extension=php_pgsql.dll
extension=pgsql.so

(3) Restart the Apache server.

3. The deprecated PostgreSQL function is called

Sometimes the above error message appears because PHP has deprecated some PostgreSQL functions, and our application Programs still use them. If you have determined that you have installed the PostgreSQL driver and completed the relevant settings, but still cannot resolve the above error, you need to check whether your code is calling deprecated PostgreSQL functions.

For example, if the pg_exec() function is called in your code, it will display the above error message. This is because the pg_exec() function has been deprecated and the pg_query() function should be used instead.

In short, in order to solve the above error message, "PHP Fatal error: Call to undefined function pg_query()", you need to first confirm whether your PHP has the PostgreSQL driver installed and correctly configure the corresponding Parameters and library files. Also, be aware of and avoid using deprecated PostgreSQL functions. If you still can't solve this problem, we recommend that you check the official documentation of PHP and PostgreSQL, or ask for help in the relevant forums.

The above is the detailed content of Solution to PHP Fatal error: Call to undefined function pg_query(). For more information, please follow other related articles on the PHP Chinese website!