Add PostgreSQL Support

Author: phpdave11

config/Database.ini

@@ -6,3 +6,8 @@ filename = "data/database.sqlite3"
 ;dsn = "mysql:host=localhost;dbname=php_survey_builder"
 ;username = "user"
 ;password = "yourpassword"
+
+; postgresql
+;dsn = "pgsql:host=localhost;dbname=php_survey_builder"
+;username = "youruser"
+;password = "yourpassword"

controllers/Controller.php

@@ -18,6 +18,7 @@ abstract class Controller
     const DSN_CONFIG_FILE = 'config/Database.ini';
     const DATABASE_SCHEMA_FILE = 'data/schema.sql';
     const DATABASE_SCHEMA_FILE_MYSQL = 'data/schema_mysql.sql';
+    const DATABASE_SCHEMA_FILE_POSTGRESQL = 'data/schema_postgresql.sql';
     const INITIAL_DATA_FILE = 'data/initial_data.sql';
     const SESSION_NAME = 'SURVEYFORMAPP';
     const RUNTIME_EXCEPTION_VIEW = 'runtime_exception.php';
@@ -233,8 +234,8 @@ protected function openDatabase()
         $username = null;
         $password = null;
 
-        if (preg_match('/^mysql/', $databaseConfig['dsn'])) {
-            $this->driver = 'mysql';
+        if (preg_match('/^(mysql|pgsql)/', $databaseConfig['dsn'], $matches)) {
+            $this->driver = $matches[1];
             if (! isset($databaseConfig['username'])) {
                 throw new RuntimeException("Database config parameter 'username' not found in config file: " . self::DSN_CONFIG_FILE);
             }
@@ -277,6 +278,8 @@ protected function createDatabaseTables()
         $schemaFile = self::DATABASE_SCHEMA_FILE;
         if ($this->driver == 'mysql') {
             $schemaFile = self::DATABASE_SCHEMA_FILE_MYSQL;
+        } elseif ($this->driver == 'pgsql') {
+            $schemaFile = self::DATABASE_SCHEMA_FILE_POSTGRESQL;
         }
 
         if (! file_exists($schemaFile)) {
@@ -298,6 +301,8 @@ protected function databaseTablesCreated()
     {
         if ($this->driver == 'mysql') {
             $sql = "show tables like 'login'";
+        } elseif ($this->driver == 'pgsql') {
+            $sql = "select table_name from information_schema.tables where table_schema='public' and table_name='login'";
         } else {
             $sql = "select count(*) from sqlite_master where type='table' and name='login'";
         }
@@ -310,6 +315,11 @@ protected function databaseTablesCreated()
                 if ($row[0] == 'login') {
                     return true;
                 }
+            } elseif ($this->driver == 'pgsql') {
+                // pgsql
+                if ($row[0] == 'login') {
+                    return true;
+                }
             } else {
                 // sqlite3
                 if ($row[0] == 1) {

data/schema_postgresql.sql

@@ -0,0 +1,46 @@
+CREATE TABLE login (
+    login_id SERIAL NOT NULL PRIMARY KEY,
+    email TEXT NOT NULL,
+    password TEXT NOT NULL,
+    first_name TEXT NOT NULL,
+    last_name TEXT NOT NULL
+);
+
+CREATE TABLE survey (
+    survey_id SERIAL NOT NULL PRIMARY KEY,
+    survey_name TEXT NOT NULL
+);
+
+CREATE TABLE question (
+    question_id SERIAL NOT NULL PRIMARY KEY,
+    survey_id INTEGER NOT NULL,
+    question_type TEXT,
+    question_text TEXT,
+    is_required INTEGER,
+    question_order INTEGER,
+    FOREIGN KEY (survey_id) REFERENCES survey (survey_id) ON UPDATE CASCADE ON DELETE CASCADE
+);
+
+CREATE TABLE choice (
+    choice_id SERIAL NOT NULL PRIMARY KEY,
+    question_id INTEGER NOT NULL,
+    choice_text TEXT,
+    choice_order INTEGER,
+    FOREIGN KEY (question_id) REFERENCES question (question_id) ON UPDATE CASCADE ON DELETE CASCADE
+);
+
+CREATE TABLE survey_response (
+    survey_response_id SERIAL NOT NULL PRIMARY KEY,
+    survey_id INTEGER NOT NULL,
+    time_taken TEXT,
+    FOREIGN KEY (survey_id) REFERENCES survey (survey_id) ON UPDATE CASCADE ON DELETE CASCADE
+);
+
+CREATE TABLE survey_answer (
+    survey_answer_id SERIAL NOT NULL PRIMARY KEY,
+    survey_response_id INTEGER NOT NULL,
+    question_id INTEGER NOT NULL,
+    answer_value TEXT NOT NULL,
+    FOREIGN KEY (survey_response_id) REFERENCES survey_response (survey_response_id) ON UPDATE CASCADE ON DELETE CASCADE,
+    FOREIGN KEY (question_id) REFERENCES question (question_id) ON UPDATE CASCADE ON DELETE CASCADE
+);

models/Survey.php

@@ -40,14 +40,20 @@ public function getQuestions(PDO $pdo)
      */
     public function getSurveyResponses(PDO $pdo)
     {
+        $driver = $pdo->getAttribute(PDO::ATTR_DRIVER_NAME);
+        $groupConcatSql = 'group_concat';
+        if ($driver == 'pgsql') {
+            $groupConcatSql = 'string_agg';
+        }
+
         if (! empty($this->survey_id)) {
             if (empty($this->questions)) {
                 $this->getQuestions($pdo);
             }
 
             $questionSubSelects = [];
             foreach ($this->questions as $question) {
-                $questionSubSelects[] = "(select group_concat(answer_value, ', ') from survey_answer sa
+                $questionSubSelects[] = "(select $groupConcatSql(answer_value, ', ') from survey_answer sa
                                           where sa.survey_response_id = sr.survey_response_id and
                                           sa.question_id = :question_id_{$question->question_id}) as question_{$question->question_id}";
                 $params["question_id_{$question->question_id}"] = $question->question_id;