PHP pg_query_params() Function: Usage and Examples

Executes a parameterized SQL query using $1, $2 placeholders.

The objective is to understand the behavior and operational limits, not only the method name.

What It Does

Executes a parameterized SQL query using $1, $2 placeholders.

Syntax and Return Value

pg_query_params(...)

The return value and exceptional cases depend on the call described here: Parameters represent data values, not SQL identifiers; query and parameter arrays must align.

Requirements: install and enable the corresponding PHP driver or extension and configure the service before running the examples.

Example 1: Basic Use

Requires a reachable PostgreSQL server and the pgsql PHP extension; asynchronous requests must be drained with pg_get_result.

<?php
$host = getenv('DB_HOST'); $user = getenv('DB_USER'); $password = getenv('DB_PASSWORD'); $database = getenv('DB_NAME');
if (!$host || !$user || $password === false || !$database) throw new RuntimeException('Missing PostgreSQL configuration');
$pg = pg_connect('host=' . $host . ' dbname=' . $database . ' user=' . $user . ' password=' . $password);
if (!$pg) { throw new RuntimeException('PostgreSQL connection failed'); }
$result = pg_query_params($pg,"SELECT $1::int * $2::int AS product",[2,5]);
echo pg_fetch_result($result,0,"product");

Example 2: A Second Scenario

Requires a reachable PostgreSQL server and the pgsql PHP extension; asynchronous requests must be drained with pg_get_result.

<?php
$host = getenv('DB_HOST'); $user = getenv('DB_USER'); $password = getenv('DB_PASSWORD'); $database = getenv('DB_NAME');
if (!$host || !$user || $password === false || !$database) throw new RuntimeException('Missing PostgreSQL configuration');
$pg = pg_connect('host=' . $host . ' dbname=' . $database . ' user=' . $user . ' password=' . $password);
if (!$pg) { throw new RuntimeException('PostgreSQL connection failed'); }
$result = pg_query_params($pg,"SELECT $1::int * $2::int AS product",[4,7]);
echo pg_fetch_result($result,0,"product");

Example 3: Practical Checks

Requires a reachable PostgreSQL server and the pgsql PHP extension; asynchronous requests must be drained with pg_get_result.

<?php
$host = getenv('DB_HOST'); $user = getenv('DB_USER'); $password = getenv('DB_PASSWORD'); $database = getenv('DB_NAME');
if (!$host || !$user || $password === false || !$database) throw new RuntimeException('Missing PostgreSQL configuration');
$pg = pg_connect('host=' . $host . ' dbname=' . $database . ' user=' . $user . ' password=' . $password);
if (!$pg) { throw new RuntimeException('PostgreSQL connection failed'); }
$result = pg_query_params($pg,"SELECT $1::int * $2::int AS product",[6,9]);
echo pg_fetch_result($result,0,"product");

Important Behavior and Edge Cases

Parameters represent data values, not SQL identifiers; query and parameter arrays must align.

For production use, also account for error handling, data validation, resource limits and environment-specific driver behavior.

Comparison with Related Approaches

Common Beginner Mistakes

Key Takeaways

• Executes a parameterized SQL query using $1, $2 placeholders.
• Parameters represent data values, not SQL identifiers; query and parameter arrays must align.
• pg_query does not separate SQL from input data.

Choose this API or pattern when its exact semantics match your task, and verify the result against the database driver and runtime used by your application.