From 489ce6556c68d68628327dcd55dd30658c3ba22f Mon Sep 17 00:00:00 2001
From: Theodore Brown <theodorejb@outlook.com>
Date: Mon, 14 Oct 2024 00:02:15 -0500
Subject: [PATCH] Implement PostgreSQL support with PDO (unfinished)

---
 lib/Pgsql.php              | 136 +++++++++++++++++++++++++++++++++++++
 lib/Pgsql/Options.php      |  16 +++++
 lib/Pgsql/Statement.php    |  71 +++++++++++++++++++
 test/DbTestCase.php        |   3 +-
 test/Pgsql/OptionsTest.php |  39 +++++++++++
 test/Pgsql/PgsqlDbTest.php |  54 +++++++++++++++
 test/src/Config.php        |  15 ++++
 7 files changed, 332 insertions(+), 2 deletions(-)
 create mode 100644 lib/Pgsql.php
 create mode 100644 lib/Pgsql/Options.php
 create mode 100644 lib/Pgsql/Statement.php
 create mode 100644 test/Pgsql/OptionsTest.php
 create mode 100644 test/Pgsql/PgsqlDbTest.php

diff --git a/lib/Pgsql.php b/lib/Pgsql.php
new file mode 100644
index 0000000..e328310
--- /dev/null
+++ b/lib/Pgsql.php
@@ -0,0 +1,136 @@
+<?php
+
+declare(strict_types=1);
+
+namespace PeachySQL;
+
+use PDO;
+use PeachySQL\Pgsql\Options;
+use PeachySQL\Pgsql\Statement;
+use PeachySQL\QueryBuilder\Insert;
+
+/**
+ * Implements the standard PeachySQL features for PostgreSQL (using PDO)
+ */
+class Pgsql extends PeachySql
+{
+    private PDO $conn;
+    private bool $usedPrepare;
+
+    public function __construct(PDO $connection, ?Options $options = null)
+    {
+        $this->conn = $connection;
+        $this->usedPrepare = true;
+
+        if ($options === null) {
+            $options = new Options();
+        }
+
+        $this->options = $options;
+    }
+
+    /**
+     * Begins a transaction
+     * @throws SqlException if an error occurs
+     */
+    public function begin(): void
+    {
+        if (!$this->conn->beginTransaction()) {
+            throw $this->getError('Failed to begin transaction', $this->conn->errorInfo());
+        }
+    }
+
+    /**
+     * Commits a transaction begun with begin()
+     * @throws SqlException if an error occurs
+     */
+    public function commit(): void
+    {
+        if (!$this->conn->commit()) {
+            throw $this->getError('Failed to commit transaction', $this->conn->errorInfo());
+        }
+    }
+
+    /**
+     * Rolls back a transaction begun with begin()
+     * @throws SqlException if an error occurs
+     */
+    public function rollback(): void
+    {
+        if (!$this->conn->rollback()) {
+            throw $this->getError('Failed to roll back transaction', $this->conn->errorInfo());
+        }
+    }
+
+    public function makeBinaryParam(?string $binaryStr, ?int $length = null): ?string
+    {
+        // binary values can be inserted directly when using MySQL
+        return $binaryStr;
+    }
+
+    /**
+     * @internal
+     */
+    public static function getError(string $msg, array $error, string $sql = '', array $params = []): SqlException
+    {
+        /** @var array{0: string, 1: int|null, 2: string|null} $error */
+        $code = $error[1] ?? 0;
+        $details = $error[2] ?? '';
+        $sqlState = $error[0];
+
+        return new SqlException($msg, $code, $details, $sqlState, $sql, $params);
+    }
+
+    /**
+     * Returns a prepared statement which can be executed multiple times
+     * @throws SqlException if an error occurs
+     */
+    public function prepare(string $sql, array $params = []): Statement
+    {
+        try {
+            if (!$stmt = $this->conn->prepare($sql)) {
+                throw $this->getError('Failed to prepare statement', $this->conn->errorInfo(), $sql, $params);
+            }
+        } catch (\PDOException $e) {
+            throw $this->getError('Failed to prepare statement', $this->conn->errorInfo(), $sql, $params);
+        }
+
+        return new Statement($stmt, $this->usedPrepare, $sql, $params);
+    }
+
+    /**
+     * Prepares and executes a single query with bound parameters
+     */
+    public function query(string $sql, array $params = []): Statement
+    {
+        $this->usedPrepare = false;
+        $stmt = $this->prepare($sql, $params);
+        $this->usedPrepare = true;
+        $stmt->execute();
+        return $stmt;
+    }
+
+    /**
+     * Performs a single bulk insert query
+     */
+    protected function insertBatch(string $table, array $colVals, int $identityIncrement = 1): BulkInsertResult
+    {
+        $sqlParams = (new Insert($this->options))->buildQuery($table, $colVals);
+        $result = $this->query($sqlParams->sql, $sqlParams->params);
+
+        try {
+            $lastId = (int) $this->conn->lastInsertId();
+        } catch (\PDOException $e) {
+            $lastId = 0;
+        }
+
+        if ($lastId) {
+            $firstId = $lastId - $identityIncrement * (count($colVals) -1);
+            $ids = range($firstId, $lastId, $identityIncrement);
+        } else {
+            $ids = [];
+        }
+
+        return new BulkInsertResult($ids, $result->getAffected());
+    }
+}
diff --git a/lib/Pgsql/Options.php b/lib/Pgsql/Options.php
new file mode 100644
index 0000000..a113850
--- /dev/null
+++ b/lib/Pgsql/Options.php
@@ -0,0 +1,16 @@
+<?php
+
+declare(strict_types=1);
+
+namespace PeachySQL\Pgsql;
+
+use PeachySQL\BaseOptions;
+
+/**
+ * Handles PostgreSQL-specific options
+ */
+class Options extends BaseOptions
+{
+    // https://stackoverflow.com/questions/6581573/what-are-the-max-number-of-allowable-parameters-per-database-provider-type
+    public int $maxBoundParams = 65_535; // 2 ** 16 - 1;
+}
diff --git a/lib/Pgsql/Statement.php b/lib/Pgsql/Statement.php
new file mode 100644
index 0000000..057275a
--- /dev/null
+++ b/lib/Pgsql/Statement.php
@@ -0,0 +1,71 @@
+<?php
+
+declare(strict_types=1);
+
+namespace PeachySQL\Pgsql;
+
+use PeachySQL\BaseStatement;
+use PeachySQL\Pgsql;
+use PDO;
+use PDOException;
+use PDOStatement;
+
+class Statement extends BaseStatement
+{
+    private ?PDOStatement $stmt;
+
+    public function __construct(PDOStatement $stmt, bool $usedPrepare, string $query, array $params)
+    {
+        parent::__construct($usedPrepare, $query, $params);
+        $this->stmt = $stmt;
+    }
+
+    public function execute(): void
+    {
+        if ($this->stmt === null) {
+            throw new \Exception('Cannot execute closed statement');
+        }
+
+        try {
+            if (!$this->stmt->execute($this->params)) {
+                throw Pgsql::getError('Failed to execute prepared statement', $this->stmt->errorInfo(), $this->query, $this->params);
+            }
+        } catch (PDOException $e) {
+            throw Pgsql::getError('Failed to execute prepared statement', $this->stmt->errorInfo(), $this->query, $this->params);
+        }
+
+        $this->affected = $this->stmt->rowCount();
+
+        if (!$this->usedPrepare && $this->stmt->columnCount() === 0) {
+            $this->close(); // no results, so statement can be closed
+        }
+    }
+
+    public function getIterator(): \Generator
+    {
+        if ($this->stmt !== null) {
+            /** @var array|false $row */
+            while ($row = $this->stmt->fetch(PDO::FETCH_ASSOC)) {
+                yield $row;
+            }
+
+            if (!$this->usedPrepare) {
+                $this->close();
+            }
+        }
+    }
+
+    /**
+     * Closes the prepared statement and deallocates the statement handle.
+     * @throws \Exception if the statement has already been closed
+     */
+    public function close(): void
+    {
+        if ($this->stmt === null) {
+            throw new \Exception('Statement has already been closed');
+        }
+
+        $this->stmt->closeCursor();
+        $this->stmt = null;
+    }
+}
diff --git a/test/DbTestCase.php b/test/DbTestCase.php
index c72c062..e9088d2 100644
--- a/test/DbTestCase.php
+++ b/test/DbTestCase.php
@@ -94,10 +94,9 @@ public function testException(PeachySql $peachySql): void
         } catch (SqlException $e) {
             $this->assertSame($badQuery, $e->query);
             $this->assertSame([], $e->params);
-            $this->assertSame('42000', $e->getSqlState());
+            $this->assertContains($e->getSqlState(), ['42000', '42601']);
             $this->assertSame($this->getExpectedBadSyntaxCode(), $e->getCode());
             $this->assertStringContainsString(' syntax ', $e->getMessage());
-            $this->assertStringContainsString(" near '", $e->getMessage());
         }
     }
 
diff --git a/test/Pgsql/OptionsTest.php b/test/Pgsql/OptionsTest.php
new file mode 100644
index 0000000..2886d15
--- /dev/null
+++ b/test/Pgsql/OptionsTest.php
@@ -0,0 +1,39 @@
+<?php
+
+declare(strict_types=1);
+
+namespace PeachySQL\Test\Pgsql;
+
+use PeachySQL\Pgsql\Options;
+use PHPUnit\Framework\TestCase;
+
+/**
+ * Tests base as well as PostgreSQL-specific configuration settings
+ */
+class OptionsTest extends TestCase
+{
+    public function testEscapeIdentifier(): void
+    {
+        $options = new Options();
+        $actual = $options->escapeIdentifier('Test"Identifier');
+        $this->assertSame('"Test""Identifier"', $actual);
+
+        try {
+            $options->escapeIdentifier(''); // should throw exception
+            $this->fail('escapeIdentifier failed to throw expected exception');
+        } catch (\InvalidArgumentException $e) {
+            $this->assertSame('Identifier cannot be blank', $e->getMessage());
+        }
+    }
+
+    public function testBuildPagination(): void
+    {
+        $options = new Options();
+
+        $page1 = $options->buildPagination(25, 0);
+        $this->assertSame('LIMIT 25 OFFSET 0', $page1);
+
+        $page3 = $options->buildPagination(100, 200);
+        $this->assertSame('LIMIT 100 OFFSET 200', $page3);
+    }
+}
diff --git a/test/Pgsql/PgsqlDbTest.php b/test/Pgsql/PgsqlDbTest.php
new file mode 100644
index 0000000..b5c47ed
--- /dev/null
+++ b/test/Pgsql/PgsqlDbTest.php
@@ -0,0 +1,54 @@
+<?php
+
+declare(strict_types=1);
+
+namespace PeachySQL\Test\Pgsql;
+
+use PeachySQL\Pgsql;
+use PeachySQL\Test\DbTestCase;
+use PeachySQL\Test\src\App;
+use PDO;
+
+/**
+ * @group pgsql
+ */
+class PgsqlDbTest extends DbTestCase
+{
+    private static ?Pgsql $db = null;
+
+    protected function getExpectedBadSyntaxCode(): int
+    {
+        return 7;
+    }
+
+    public static function dbProvider(): array
+    {
+        if (!self::$db) {
+            $c = App::$config;
+            $pdo = new PDO($c->getPgsqlDsn(), $c->getPgsqlUser(), $c->getPgsqlPassword());
+
+            self::$db = new Pgsql($pdo);
+            self::createTestTable(self::$db);
+        }
+
+        return [
+            [self::$db],
+        ];
+    }
+
+    private static function createTestTable(Pgsql $db): void
+    {
+        $sql = "
+            CREATE TABLE Users (
+                user_id SERIAL PRIMARY KEY,
+                name VARCHAR(50) NOT NULL,
+                dob DATE NOT NULL,
+                weight REAL NOT NULL,
+                isDisabled BOOLEAN NOT NULL,
+                uuid bytea NULL
+            )";
+
+        $db->query("DROP TABLE IF EXISTS Users");
+        $db->query($sql);
+    }
+}
diff --git a/test/src/Config.php b/test/src/Config.php
index 68dd972..0cc4861 100644
--- a/test/src/Config.php
+++ b/test/src/Config.php
@@ -29,6 +29,21 @@ public function getMysqlDatabase(): string
         return 'PeachySQL';
     }
 
+    public function getPgsqlDsn(): string
+    {
+        return "pgsql:host=localhost;dbname=PeachySQL";
+    }
+
+    public function getPgsqlUser(): string
+    {
+        return 'postgres';
+    }
+
+    public function getPgsqlPassword(): string
+    {
+        return '';
+    }
+
     public function getSqlsrvServer(): string
     {
         return '(local)\SQLEXPRESS';