Add medicine search DB indexes and prefix query optimization

app/Controllers/Opd_prescription.php

@@ -4519,9 +4519,9 @@ class Opd_prescription extends BaseController
         $builder = $this->db->table($table)->select($select);
         if ($q !== '') {
             $builder->groupStart()
-                ->like($nameField, $q);
+                ->like($nameField, $q, 'after');
             if ($formField !== null) {
-                $builder->orLike($formField, $q);
+                $builder->orLike($formField, $q, 'after');
             }
             $builder->groupEnd();
         }

app/Database/Migrations/2026-04-08-000041_AddMedicineSearchIndexes.php

@@ -0,0 +1,84 @@
+<?php
+
+namespace App\Database\Migrations;
+
+use CodeIgniter\Database\Migration;
+
+class AddMedicineSearchIndexes extends Migration
+{
+    private function tableExists(string $table): bool
+    {
+        $rows = $this->db->query('SHOW TABLES LIKE ?', [$table])->getResultArray();
+
+        return ! empty($rows);
+    }
+
+    private function fieldExists(string $table, string $field): bool
+    {
+        if (! $this->tableExists($table)) {
+            return false;
+        }
+
+        $rows = $this->db->query('SHOW COLUMNS FROM `' . $table . '` LIKE ?', [$field])->getResultArray();
+
+        return ! empty($rows);
+    }
+
+    private function indexExists(string $table, string $indexName): bool
+    {
+        if (! $this->tableExists($table)) {
+            return false;
+        }
+
+        $rows = $this->db->query('SHOW INDEX FROM `' . $table . '` WHERE Key_name = ?', [$indexName])->getResultArray();
+
+        return ! empty($rows);
+    }
+
+    private function addIndexIfMissing(string $table, string $indexName, string $columns): void
+    {
+        if (! $this->tableExists($table) || $this->indexExists($table, $indexName)) {
+            return;
+        }
+
+        $this->db->query('ALTER TABLE `' . $table . '` ADD INDEX `' . $indexName . '` (' . $columns . ')');
+    }
+
+    public function up(): void
+    {
+        if (! $this->tableExists('opd_med_master')) {
+            return;
+        }
+
+        if ($this->fieldExists('opd_med_master', 'item_name')) {
+            $this->addIndexIfMissing('opd_med_master', 'idx_opd_med_master_item_name', '`item_name`');
+        }
+
+        if ($this->fieldExists('opd_med_master', 'formulation')) {
+            $this->addIndexIfMissing('opd_med_master', 'idx_opd_med_master_formulation', '`formulation`');
+        }
+
+        if ($this->fieldExists('opd_med_master', 'item_name') && $this->fieldExists('opd_med_master', 'formulation')) {
+            $this->addIndexIfMissing('opd_med_master', 'idx_opd_med_master_item_form', '`item_name`,`formulation`');
+        }
+    }
+
+    public function down(): void
+    {
+        if (! $this->tableExists('opd_med_master')) {
+            return;
+        }
+
+        $indexes = [
+            'idx_opd_med_master_item_name',
+            'idx_opd_med_master_formulation',
+            'idx_opd_med_master_item_form',
+        ];
+
+        foreach ($indexes as $index) {
+            if ($this->indexExists('opd_med_master', $index)) {
+                $this->db->query('ALTER TABLE `opd_med_master` DROP INDEX `' . $index . '`');
+            }
+        }
+    }
+}