diff --git a/pg4wp/rewriters/AlterTableSQLRewriter.php b/pg4wp/rewriters/AlterTableSQLRewriter.php
index 5fccd84..191d099 100644
--- a/pg4wp/rewriters/AlterTableSQLRewriter.php
+++ b/pg4wp/rewriters/AlterTableSQLRewriter.php
@@ -31,28 +31,62 @@ class AlterTableSQLRewriter extends AbstractSQLRewriter
 
         $sql = $this->rewrite_numeric_type($sql);
 
+        if (str_contains($sql, 'ADD INDEX') || str_contains($sql, 'ADD UNIQUE INDEX')) {
+            $sql = $this->rewriteAddIndex($sql);
+            return $sql;
+        }
         if (str_contains($sql, 'CHANGE COLUMN')) {
             $sql = $this->rewriteChangeColumn($sql);
+            return $sql;
         }
         if (str_contains($sql, 'ALTER COLUMN')) {
             $sql = $this->rewriteAlterColumn($sql);
+            return $sql;
         }
         if (str_contains($sql, 'ADD COLUMN')) {
             $sql = $this->rewriteAddColumn($sql);
+            return $sql;
         }
         if (str_contains($sql, 'ADD KEY') || str_contains($sql, 'ADD UNIQUE KEY')) {
             $sql = $this->rewriteAddKey($sql);
+            return $sql;
         }
         if (str_contains($sql, 'DROP INDEX')) {
             $sql = $this->rewriteDropIndex($sql);
+            return $sql;
         }
         if (str_contains($sql, 'DROP PRIMARY KEY')) {
             $sql = $this->rewriteDropPrimaryKey($sql);
+            return $sql;
         }
 
         return $sql;
     }
 
+    private function rewriteAddIndex(string $sql): string 
+    {
+        $pattern = '/ALTER TABLE\s+(\w+)\s+ADD (UNIQUE |)INDEX\s+([^\s]+)\s+\(((?:[^\(\)]+|\([^\(\)]+\))+)\)/';
+
+        if(1 === preg_match($pattern, $sql, $matches)) {
+            $table = $matches[1];
+            $unique = $matches[2];
+            $index = $matches[3];
+            $columns = $matches[4];
+    
+            // Remove prefix indexing
+            // Rarely used and apparently unnecessary for current uses
+            $columns = preg_replace('/\([^\)]*\)/', '', $columns);
+    
+            // Workaround for index name duplicate
+            $index = $table . '_' . $index;
+            
+            // Add backticks around index name and column name, and include IF NOT EXISTS clause
+            $sql = "CREATE {$unique}INDEX IF NOT EXISTS `{$index}` ON `{$table}` (`{$columns}`)";
+        }
+    
+        return $sql;
+    }
+
     private function rewriteChangeColumn(string $sql): string
     {
         $pattern = '/ALTER TABLE\s+(\w+)\s+CHANGE COLUMN\s+([^\s]+)\s+([^\s]+)\s+([^ ]+)( unsigned|)\s*(NOT NULL|)\s*(default (.+)|)/';
@@ -164,7 +198,7 @@ class AlterTableSQLRewriter extends AbstractSQLRewriter
         if(1 === preg_match($pattern, $sql, $matches)) {
             $table = $matches[1];
             $index = $matches[2];
-            $sql = "DROP INDEX ${table}_${index}";
+            $sql = "DROP INDEX {$table}_{$index}";
         }
 
         return $sql;
@@ -176,7 +210,7 @@ class AlterTableSQLRewriter extends AbstractSQLRewriter
 
         if(1 === preg_match($pattern, $sql, $matches)) {
             $table = $matches[1];
-            $sql = "ALTER TABLE ${table} DROP CONSTRAINT ${table}_pkey";
+            $sql = "ALTER TABLE {$table} DROP CONSTRAINT {$table}_pkey";
         }
 
         return $sql;
diff --git a/pg4wp/rewriters/SelectSQLRewriter.php b/pg4wp/rewriters/SelectSQLRewriter.php
index ea861d9..129dbb1 100644
--- a/pg4wp/rewriters/SelectSQLRewriter.php
+++ b/pg4wp/rewriters/SelectSQLRewriter.php
@@ -123,7 +123,6 @@ class SelectSQLRewriter extends AbstractSQLRewriter
         if(isset($wpdb)) {
             $sql = str_replace('GROUP BY ' . $wpdb->prefix . 'posts.ID', '', $sql);
         }
-        $sql = str_replace("!= ''", '<> 0', $sql);
 
         // MySQL 'LIKE' is case insensitive by default, whereas PostgreSQL 'LIKE' is
         $sql = str_replace(' LIKE ', ' ILIKE ', $sql);
diff --git a/phpunit.xml b/phpunit.xml
index 02f5990..0078610 100644
--- a/phpunit.xml
+++ b/phpunit.xml
@@ -1,9 +1,12 @@
 <?xml version="1.0" encoding="UTF-8"?>
 <phpunit
   xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"     
+  displayDetailsOnTestsThatTriggerDeprecations="true"
+  displayDetailsOnTestsThatTriggerErrors="true"
+  displayDetailsOnTestsThatTriggerNotices="true"
   displayDetailsOnTestsThatTriggerWarnings="true"
   colors="true">
-     <testsuites>
+    <testsuites>
         <testsuite name="tests">
             <directory>tests</directory>
         </testsuite>
diff --git a/tests/rewriteTest.php b/tests/rewriteTest.php
index eeb5f8c..25e8f0e 100644
--- a/tests/rewriteTest.php
+++ b/tests/rewriteTest.php
@@ -425,9 +425,73 @@ final class rewriteTest extends TestCase
         $this->assertSame(trim($expected), trim($postgresql));
     }
 
+    public function test_it_doesnt_rewrite_when_it_doesnt_need_to()
+    {
+        $sql = <<<SQL
+            SELECT p.ID FROM wp_posts p 
+            WHERE post_type='scheduled-action' 
+            AND p.post_status IN ('pending') 
+            AND p.post_modified_gmt <= '2023-11-27 14:23:34' 
+            AND p.post_password != '' ORDER BY p.post_date_gmt ASC LIMIT 0, 20
+        SQL;
+
+        $expected = <<<SQL
+            SELECT p."ID" , p.post_date_gmt FROM wp_posts p 
+            WHERE post_type='scheduled-action' 
+            AND p.post_status IN ('pending') 
+            AND p.post_modified_gmt <= '2023-11-27 14:23:34' 
+            AND p.post_password != '' ORDER BY p.post_date_gmt ASC LIMIT 20 OFFSET 0
+        SQL;
+
+        $postgresql = pg4wp_rewrite($sql);
+        $this->assertSame(trim($expected), trim($postgresql));
+    }
+
+    public function test_it_handles_alter_tables_with_indexes() 
+    {
+        $sql = <<<SQL
+            ALTER TABLE wp_e_events ADD INDEX `created_at_index` (`created_at`)
+        SQL;
+
+        $expected = <<<SQL
+            CREATE INDEX IF NOT EXISTS wp_e_events_created_at_index ON wp_e_events (created_at)
+        SQL;
+
+        $postgresql = pg4wp_rewrite($sql);
+        $this->assertSame(trim($expected), trim($postgresql));
+
+    }
+
+    public function test_it_handles_alter_tables_with_unique_indexes() 
+    {
+        $sql = <<<SQL
+            ALTER TABLE wp_e_events ADD UNIQUE INDEX `created_at_index` (`created_at`)
+        SQL;
+
+        $expected = <<<SQL
+            CREATE UNIQUE INDEX IF NOT EXISTS wp_e_events_created_at_index ON wp_e_events (created_at)
+        SQL;
+
+        $postgresql = pg4wp_rewrite($sql);
+        $this->assertSame(trim($expected), trim($postgresql));
+    }
+
+    public function test_it_doesnt_remove_single_quotes() 
+    {
+        $sql = <<<SQL
+            SELECT COUNT(*) FROM wp_comments WHERE user_id = 5 AND comment_approved = '1'
+        SQL;
+
+        $expected = <<<SQL
+            SELECT COUNT(*) FROM wp_comments WHERE user_id = 5 AND comment_approved = '1'
+        SQL;
+
+        $postgresql = pg4wp_rewrite($sql);
+        $this->assertSame(trim($expected), trim($postgresql));
+    }
 
 
-
+    
 
     protected function setUp(): void
     {