From 109fbd5a15465676fc3ac418ca1ba90dd76153ec Mon Sep 17 00:00:00 2001
From: Marina Glancy <marina@moodle.com>
Date: Thu, 12 Oct 2017 11:17:26 +0800
Subject: [PATCH] MDL-46269 dml: Add casesensitive argument to sql_regex()

---
 lib/dml/moodle_database.php               |  4 ++-
 lib/dml/mysqli_native_moodle_database.php | 19 ++++++++++--
 lib/dml/pgsql_native_moodle_database.php  |  8 ++++--
 lib/dml/tests/dml_test.php                | 35 ++++++++++++++---------
 4 files changed, 48 insertions(+), 18 deletions(-)

diff --git a/lib/dml/moodle_database.php b/lib/dml/moodle_database.php
index 874182345be..1b72c00955c 100644
--- a/lib/dml/moodle_database.php
+++ b/lib/dml/moodle_database.php
@@ -2341,10 +2341,12 @@ abstract class moodle_database {
     /**
      * Returns the driver specific syntax (SQL part) for matching regex positively or negatively (inverted matching).
      * Eg: 'REGEXP':'NOT REGEXP' or '~*' : '!~*'
+     *
      * @param bool $positivematch
+     * @param bool $casesensitive
      * @return string or empty if not supported
      */
-    public function sql_regex($positivematch=true) {
+    public function sql_regex($positivematch = true, $casesensitive = false) {
         return '';
     }
 
diff --git a/lib/dml/mysqli_native_moodle_database.php b/lib/dml/mysqli_native_moodle_database.php
index 1934699c1f3..2232e2c09c2 100644
--- a/lib/dml/mysqli_native_moodle_database.php
+++ b/lib/dml/mysqli_native_moodle_database.php
@@ -1738,10 +1738,25 @@ class mysqli_native_moodle_database extends moodle_database {
     /**
      * Return regex positive or negative match sql
      * @param bool $positivematch
+     * @param bool $casesensitive
      * @return string or empty if not supported
      */
-    public function sql_regex($positivematch=true) {
-        return $positivematch ? 'REGEXP' : 'NOT REGEXP';
+    public function sql_regex($positivematch = true, $casesensitive = false) {
+        $collation = '';
+        if ($casesensitive) {
+            if (substr($this->get_dbcollation(), -4) !== '_bin') {
+                $collationinfo = explode('_', $this->get_dbcollation());
+                $collation = 'COLLATE ' . $collationinfo[0] . '_bin ';
+            }
+        } else {
+            if ($this->get_dbcollation() == 'utf8_bin') {
+                $collation = 'COLLATE utf8_unicode_ci ';
+            } else if ($this->get_dbcollation() == 'utf8mb4_bin') {
+                $collation = 'COLLATE utf8mb4_unicode_ci ';
+            }
+        }
+
+        return $collation . ($positivematch ? 'REGEXP' : 'NOT REGEXP');
     }
 
     /**
diff --git a/lib/dml/pgsql_native_moodle_database.php b/lib/dml/pgsql_native_moodle_database.php
index aaac5c87ef8..44d298c03a6 100644
--- a/lib/dml/pgsql_native_moodle_database.php
+++ b/lib/dml/pgsql_native_moodle_database.php
@@ -1260,8 +1260,12 @@ class pgsql_native_moodle_database extends moodle_database {
         return true;
     }
 
-    public function sql_regex($positivematch=true) {
-        return $positivematch ? '~*' : '!~*';
+    public function sql_regex($positivematch = true, $casesensitive = false) {
+        if ($casesensitive) {
+            return $positivematch ? '~' : '!~';
+        } else {
+            return $positivematch ? '~*' : '!~*';
+        }
     }
 
     /**
diff --git a/lib/dml/tests/dml_test.php b/lib/dml/tests/dml_test.php
index 87865851c35..866625da722 100644
--- a/lib/dml/tests/dml_test.php
+++ b/lib/dml/tests/dml_test.php
@@ -4347,6 +4347,9 @@ class core_dml_testcase extends database_driver_testcase {
     public function test_sql_regex() {
         $DB = $this->tdb;
         $dbman = $DB->get_manager();
+        if (!$DB->sql_regex_supported()) {
+            $this->markTestSkipped($DB->get_name().' does not support regular expressions');
+        }
 
         $table = $this->get_test_table();
         $tablename = $table->getName();
@@ -4356,27 +4359,33 @@ class core_dml_testcase extends database_driver_testcase {
         $table->add_key('primary', XMLDB_KEY_PRIMARY, array('id'));
         $dbman->create_table($table);
 
-        $DB->insert_record($tablename, array('name'=>'lalala'));
+        $DB->insert_record($tablename, array('name'=>'LALALA'));
         $DB->insert_record($tablename, array('name'=>'holaaa'));
         $DB->insert_record($tablename, array('name'=>'aouch'));
 
+        // Regex /a$/i (case-insensitive).
         $sql = "SELECT * FROM {{$tablename}} WHERE name ".$DB->sql_regex()." ?";
         $params = array('a$');
-        if ($DB->sql_regex_supported()) {
-            $records = $DB->get_records_sql($sql, $params);
-            $this->assertCount(2, $records);
-        } else {
-            $this->assertTrue(true, 'Regexp operations not supported. Test skipped');
-        }
+        $records = $DB->get_records_sql($sql, $params);
+        $this->assertCount(2, $records);
 
+        // Regex ! (not) /.a/i (case insensitive).
         $sql = "SELECT * FROM {{$tablename}} WHERE name ".$DB->sql_regex(false)." ?";
         $params = array('.a');
-        if ($DB->sql_regex_supported()) {
-            $records = $DB->get_records_sql($sql, $params);
-            $this->assertCount(1, $records);
-        } else {
-            $this->assertTrue(true, 'Regexp operations not supported. Test skipped');
-        }
+        $records = $DB->get_records_sql($sql, $params);
+        $this->assertCount(1, $records);
+
+        // Regex /a$/ (case-sensitive).
+        $sql = "SELECT * FROM {{$tablename}} WHERE name ".$DB->sql_regex(true, true)." ?";
+        $params = array('a$');
+        $records = $DB->get_records_sql($sql, $params);
+        $this->assertCount(1, $records);
+
+        // Regex ! (not) /.a/ (case sensitive).
+        $sql = "SELECT * FROM {{$tablename}} WHERE name ".$DB->sql_regex(false, true)." ?";
+        $params = array('.a');
+        $records = $DB->get_records_sql($sql, $params);
+        $this->assertCount(2, $records);
 
     }