diff --git a/htdocs/admin/system/database-tables.php b/htdocs/admin/system/database-tables.php
index fd361b504fc4c..62bf71af96c8b 100644
--- a/htdocs/admin/system/database-tables.php
+++ b/htdocs/admin/system/database-tables.php
@@ -53,12 +53,17 @@
 	$db->query($sql);
 }
 if ($action == 'convertutf8') {
-	$sql = "ALTER TABLE ".$db->sanitize($table)." CHARACTER SET utf8 COLLATE utf8_unicode_ci";	// Set the default value on table
+	$collation = 'utf8_unicode_ci';
+	$defaultcollation = $db->getDefaultCollationDatabase();
+	if (preg_match('/general/', $defaultcollation)) {
+		$collation = 'utf8_general_ci';
+	}
+	$sql = "ALTER TABLE ".$db->sanitize($table)." CHARACTER SET utf8 COLLATE ".$db->sanitize($collation);	// Set the default value on table
 	$resql1 = $db->query($sql);
 	if (!$resql1) {
 		setEventMessages($db->lasterror(), null, 'warnings');
 	} else {
-		$sql = "ALTER TABLE ".$db->sanitize($table)." CONVERT TO CHARACTER SET utf8 COLLATE utf8_unicode_ci";	// Switch fields (may fails due to foreign key)
+		$sql = "ALTER TABLE ".$db->sanitize($table)." CONVERT TO CHARACTER SET utf8 COLLATE ".$db->sanitize($collation);	// Switch fields (may fails due to foreign key)
 		$resql2 = $db->query($sql);
 		if (!$resql2) {
 			setEventMessages($db->lasterror(), null, 'warnings');
@@ -66,12 +71,17 @@
 	}
 }
 if ($action == 'convertutf8mb4') {
-	$sql = "ALTER TABLE ".$db->sanitize($table)." CHARACTER SET utf8mb4 COLLATE utf8mb4_unicode_ci";	// Set the default value on table
+	$collation = 'utf8mb4_unicode_ci';
+	$defaultcollation = $db->getDefaultCollationDatabase();
+	if (preg_match('/general/', $defaultcollation)) {
+		$collation = 'utf8mb4_general_ci';
+	}
+	$sql = "ALTER TABLE ".$db->sanitize($table)." CHARACTER SET utf8mb4 COLLATE ".$db->sanitize($collation);	// Set the default value on table
 	$resql1 = $db->query($sql);
 	if (!$resql1) {
 		setEventMessages($db->lasterror(), null, 'warnings');
 	} else {
-		$sql = "ALTER TABLE ".$db->sanitize($table)." CONVERT TO CHARACTER SET utf8mb4 COLLATE utf8mb4_unicode_ci";	// Switch fields (may fails due to foreign key)
+		$sql = "ALTER TABLE ".$db->sanitize($table)." CONVERT TO CHARACTER SET utf8mb4 COLLATE ".$db->sanitize($collation);	// Switch fields (may fails due to foreign key)
 		$resql2 = $db->query($sql);
 		if (!$resql2) {
 			setEventMessages($db->lasterror(), null, 'warnings');
diff --git a/htdocs/admin/system/database.php b/htdocs/admin/system/database.php
index 51f5a4afbee1b..d6fd9155172cd 100644
--- a/htdocs/admin/system/database.php
+++ b/htdocs/admin/system/database.php
@@ -29,11 +29,34 @@
 
 $langs->load("admin");
 
+$action = GETPOST('action', 'aZ09');
+
 if (!$user->admin) {
 	accessforbidden();
 }
 
 
+/*
+ * Actions
+ */
+
+if ($action == 'convertutf8unicode') {			// Test on permission already done.
+	$sql = "ALTER DATABASE ".$db->sanitize($table[0])." CHARACTER SET utf8 COLLATE utf8_unicode_ci";
+	$db->query($sql);
+}
+if ($action == 'convertutf8mb4unicode') {		// Test on permission already done.
+	$sql = "ALTER DATABASE ".$db->sanitize($table[0])." CHARACTER SET utf8mb4 COLLATE utf8mb4_unicode_ci";
+	$db->query($sql);
+}
+if ($action == 'convertutf8general') {			// Test on permission already done.
+	$sql = "ALTER DATABASE ".$db->sanitize($table[0])." CHARACTER SET utf8 COLLATE utf8_general_ci";
+	$db->query($sql);
+}
+if ($action == 'convertutf8mb4general') {		// Test on permission already done.
+	$sql = "ALTER DATABASE ".$db->sanitize($table[0])." CHARACTER SET utf8mb4 COLLATE utf8mb4_general_ci";
+	$db->query($sql);
+}
+
 
 /*
  * View
@@ -59,14 +82,33 @@
 print '<tr class="oddeven"><td width="300">'.$langs->trans("Password").'</td><td>'.preg_replace('/./i', '*', $dolibarr_main_db_pass).'</td></tr>'."\n";
 print '<tr class="oddeven"><td width="300">'.$langs->trans("DBStoringCharset").'</td><td>'.$db->getDefaultCharacterSetDatabase();
 if ($db->type == 'mysqli') {
-	print ' '.$form->textwithpicto('', $langs->transnoentitiesnoconv("HelpMariaDBToGetValue", "SHOW VARIABLES LIKE 'character_set_database'").'<br>'.$langs->transnoentitiesnoconv("HelpMariaDBToGetPossibleValues", "SHOW CHARSET"));
+	print ' '.$form->textwithpicto('', $langs->transnoentitiesnoconv("HelpMariaDBToGetValue", "<br>SHOW VARIABLES LIKE 'character_set_database' (cached)<br>You can avoid cache effect with:<br>SELECT DEFAULT_CHARACTER_SET_NAME FROM information_schema.SCHEMATA WHERE SCHEMA_NAME = '".$conf->db->name."'").'<br>'.$langs->transnoentitiesnoconv("HelpMariaDBToGetPossibleValues", "<br>SHOW CHARSET"));
 	// We can use $db->getDefaultCharacterSetDatabase(),  $db->getListOfCharacterSet(),
 }
 print '</td></tr>'."\n";
-print '<tr class="oddeven"><td width="300">'.$langs->trans("DBSortingCharset").'</td><td>'.$db->getDefaultCollationDatabase();
+print '<tr class="oddeven"><td width="300">'.$langs->trans("DBSortingCharset").'</td><td>';
+$defaultcollation = $db->getDefaultCollationDatabase();
+print dolPrintHTML($defaultcollation);
 if ($db->type == 'mysqli') {
-	print ' '.$form->textwithpicto('', $langs->transnoentitiesnoconv("HelpMariaDBToGetValue", "SHOW VARIABLES LIKE 'collation_database'").'<br>'.$langs->transnoentitiesnoconv("HelpMariaDBToGetPossibleValues", "SHOW COLLATION"));
+	if ($defaultcollation != $dolibarr_main_db_collation) {
+		print img_warning('The database default value of collation '.$defaultcollation.' differs from conf setup '.$dolibarr_main_db_collation);
+	}
+	print ' '.$form->textwithpicto('', $langs->transnoentitiesnoconv("HelpMariaDBToGetValue", "<br>SHOW VARIABLES LIKE 'collation_database' (cached)<br>You can avoid cache effect with:<br>SELECT DEFAULT_COLLATION_NAME FROM information_schema.SCHEMATA WHERE SCHEMA_NAME = '".$conf->db->name."'").'<br>'.$langs->transnoentitiesnoconv("HelpMariaDBToGetPossibleValues", "<br>SHOW COLLATION"));
 	// We can use $db->getDefaultCollationDatabase(), $db->getListOfCollation();
+
+	print ' &nbsp; &nbsp; &nbsp; <span class="opacitymedium small">'.$langs->trans("ConvertInto");
+	if (!in_array($defaultcollation, array("utf8_unicode_ci"))) {
+		print ' &nbsp; <a class="reposition" href="'.DOL_URL_ROOT.'/admin/system/database.php?action=convertutf8unicode&token='.newToken().'">utf8 unicode</a>';
+	}
+	if (!in_array($defaultcollation, array("utf8_general_ci"))) {
+		print ' &nbsp;  <a class="reposition" href="'.DOL_URL_ROOT.'/admin/system/database.php?action=convertutf8general&token='.newToken().'">utf8 general</a>';
+	}
+	if (!in_array($defaultcollation, array("utf8mb4_unicode_ci"))) {
+		print ' &nbsp; <a class="reposition" href="'.DOL_URL_ROOT.'/admin/system/database.php?action=convertutf8mb4unicode&&token='.newToken().'">utf8mb4 unicode</a>';
+	}
+	if (!in_array($defaultcollation, array("utf8mb4_general_ci"))) {
+		print ' &nbsp; <a class="reposition" href="'.DOL_URL_ROOT.'/admin/system/database.php?action=convertutf8mb4general&&token='.newToken().'">utf8mb4 general</a>';
+	}
 }
 print '</td></tr>'."\n";
 print '</table>';
diff --git a/htdocs/admin/system/dbtable.php b/htdocs/admin/system/dbtable.php
index 203d41b805d42..68d2b98cdf58e 100644
--- a/htdocs/admin/system/dbtable.php
+++ b/htdocs/admin/system/dbtable.php
@@ -56,8 +56,17 @@
 				$sql = "ALTER TABLE ".$db->sanitize($table)." MODIFY ".$db->sanitize($row[0])." ".$row[1]." CHARACTER SET utf8";		// We must not sanitize the $row[1]
 				$db->query($sql);
 
-				$sql = "ALTER TABLE ".$db->sanitize($table)." MODIFY ".$db->sanitize($row[0])." ".$row[1]." COLLATE utf8_unicode_ci";	// We must not sanitize the $row[1]
-				$db->query($sql);
+				$collation = 'utf8_unicode_ci';
+				$defaultcollation = $db->getDefaultCollationDatabase();
+				if (preg_match('/general/', $defaultcollation)) {
+					$collation = 'utf8_general_ci';
+				}
+
+				$sql = "ALTER TABLE ".$db->sanitize($table)." MODIFY ".$db->sanitize($row[0])." ".$row[1]." COLLATE ".$db->sanitize($collation);	// We must not sanitize the $row[1]
+				$reslq2 = $db->query($sql);
+				if (!$resql2) {
+					setEventMessages($db->lasterror(), null, 'warnings');
+				}
 
 				break;
 			}
@@ -77,8 +86,17 @@
 				$sql = "ALTER TABLE ".$db->sanitize($table)." MODIFY ".$db->sanitize($row[0])." ".$row[1]." CHARACTER SET utf8mb4";		// We must not sanitize the $row[1]
 				$db->query($sql);
 
-				$sql = "ALTER TABLE ".$db->sanitize($table)." MODIFY ".$db->sanitize($row[0])." ".$row[1]." COLLATE utf8mb4_unicode_ci";	// We must not sanitize the $row[1]
-				$db->query($sql);
+				$collation = 'utf8mb4_unicode_ci';
+				$defaultcollation = $db->getDefaultCollationDatabase();
+				if (preg_match('/general/', $defaultcollation)) {
+					$collation = 'utf8mb4_general_ci';
+				}
+
+				$sql = "ALTER TABLE ".$db->sanitize($table)." MODIFY ".$db->sanitize($row[0])." ".$row[1]." COLLATE ".$db->sanitize($collation);	// We must not sanitize the $row[1]
+				$resql2 = $db->query($sql);
+				if (!$resql2) {
+					setEventMessages($db->lasterror(), null, 'warnings');
+				}
 
 				break;
 			}
diff --git a/htdocs/core/db/mysqli.class.php b/htdocs/core/db/mysqli.class.php
index 1592aee417fdb..b0776c70842d3 100644
--- a/htdocs/core/db/mysqli.class.php
+++ b/htdocs/core/db/mysqli.class.php
@@ -106,6 +106,8 @@ public function __construct($type, $host, $user, $pass, $name = '', $port = 0)
 			dol_syslog(get_class($this)."::DoliDBMysqli Connect error: ".$this->error, LOG_ERR);
 		}
 
+		$disableforcecharset = 0;	// Set to 1 to test without charset forcing
+
 		// If server connection is ok, we try to connect to the database
 		if ($this->connected && $name) {
 			if ($this->select_db($name)) {
@@ -119,7 +121,6 @@ public function __construct($type, $host, $user, $pass, $name = '', $port = 0)
 					$clientmustbe = 'utf8';
 				}
 
-				$disableforcecharset = 0;	// Set to 1 to test without charset forcing
 				if (empty($disableforcecharset) && $this->db->character_set_name() != $clientmustbe) {
 					try {
 						dol_syslog(get_class($this)."::DoliDBMysqli You should set the \$dolibarr_main_db_character_set and \$dolibarr_main_db_collation for the PHP to the same as the database default, so to ".$this->db->character_set_name(). " or upgrade database default to ".$clientmustbe.".", LOG_WARNING);
@@ -174,7 +175,7 @@ public function __construct($type, $host, $user, $pass, $name = '', $port = 0)
 					$clientmustbe = 'utf8';
 				}
 
-				if ($this->db->character_set_name() != $clientmustbe) {
+				if (empty($disableforcecharset) && $this->db->character_set_name() != $clientmustbe) {
 					$this->db->set_charset($clientmustbe); // This set utf8_unicode_ci
 
 					$collation = $conf->db->dolibarr_main_db_collation;
diff --git a/htdocs/install/repair.php b/htdocs/install/repair.php
index 43d9dcf422f83..a7272675d7eda 100644
--- a/htdocs/install/repair.php
+++ b/htdocs/install/repair.php
@@ -1347,10 +1347,16 @@
 				continue;
 			}
 
+			$collation = 'utf8_unicode_ci';
+			$defaultcollation = $db->getDefaultCollationDatabase();
+			if (preg_match('/general/', $defaultcollation)) {
+				$collation = 'utf8_general_ci';
+			}
+
 			print '<tr><td colspan="2">';
 			print $table[0];
 			$sql1 = "ALTER TABLE ".$db->sanitize($table[0])." ROW_FORMAT=dynamic";
-			$sql2 = "ALTER TABLE ".$db->sanitize($table[0])." CONVERT TO CHARACTER SET utf8 COLLATE utf8_unicode_ci";
+			$sql2 = "ALTER TABLE ".$db->sanitize($table[0])." CONVERT TO CHARACTER SET utf8 COLLATE ".$db->sanitize($collation);
 			print '<!-- '.$sql1.' -->';
 			print '<!-- '.$sql2.' -->';
 			if ($force_utf8_on_tables == 'confirmed') {
@@ -1471,10 +1477,16 @@
 				continue;
 			}
 
+			$collation = 'utf8mb4_unicode_ci';
+			$defaultcollation = $db->getDefaultCollationDatabase();
+			if (preg_match('/general/', $defaultcollation)) {
+				$collation = 'utf8mb4_general_ci';
+			}
+
 			print '<tr><td colspan="2">';
 			print $table[0];
 			$sql1 = "ALTER TABLE ".$db->sanitize($table[0])." ROW_FORMAT=dynamic";
-			$sql2 = "ALTER TABLE ".$db->sanitize($table[0])." CONVERT TO CHARACTER SET utf8mb4 COLLATE utf8mb4_unicode_ci";
+			$sql2 = "ALTER TABLE ".$db->sanitize($table[0])." CONVERT TO CHARACTER SET utf8mb4 COLLATE ".$db->sanitize($collation);
 			print '<!-- '.$sql1.' -->';
 			print '<!-- '.$sql2.' -->';
 			if ($force_utf8mb4_on_tables == 'confirmed') {