diff --git a/htdocs/blockedlog/class/blockedlog.class.php b/htdocs/blockedlog/class/blockedlog.class.php
index a7be2fb3630..83ab700f59a 100644
--- a/htdocs/blockedlog/class/blockedlog.class.php
+++ b/htdocs/blockedlog/class/blockedlog.class.php
@@ -796,7 +796,7 @@ class BlockedLog
 	{
 
 		$res = $this->db->query("UPDATE ".MAIN_DB_PREFIX."blockedlog SET certified=1 WHERE rowid=".((int) $this->id));
-		if ($res === false) {
+		if (!$res) {
 			return false;
 		}
 
diff --git a/htdocs/compta/facture/class/facture-rec.class.php b/htdocs/compta/facture/class/facture-rec.class.php
index 100334e046a..19f70554637 100644
--- a/htdocs/compta/facture/class/facture-rec.class.php
+++ b/htdocs/compta/facture/class/facture-rec.class.php
@@ -1977,7 +1977,7 @@ class FactureLigneRec extends CommonInvoiceLine
 			$sql = 'DELETE FROM '.MAIN_DB_PREFIX.$this->table_element.' WHERE rowid='.((int) $this->id);
 
 			$res = $this->db->query($sql);
-			if ($res === false) {
+			if (!$res) {
 				$error++;
 				$this->errors[] = $this->db->lasterror();
 			}
diff --git a/htdocs/core/class/commonobject.class.php b/htdocs/core/class/commonobject.class.php
index 534679554c2..c7d99fae998 100644
--- a/htdocs/core/class/commonobject.class.php
+++ b/htdocs/core/class/commonobject.class.php
@@ -1273,7 +1273,7 @@ abstract class CommonObject
 			$sql .= " LEFT JOIN ".MAIN_DB_PREFIX."socpeople t on ec.fk_socpeople = t.rowid";
 		}
 		$sql .= " WHERE ec.element_id = ".((int) $this->id);
-		$sql .= " AND ec.fk_c_type_contact=tc.rowid";
+		$sql .= " AND ec.fk_c_type_contact = tc.rowid";
 		$sql .= " AND tc.element = '".$this->db->escape($this->element)."'";
 		if ($code) {
 			$sql .= " AND tc.code = '".$this->db->escape($code)."'";
@@ -8740,7 +8740,7 @@ abstract class CommonObject
 			$sql .= " VALUES (".implode(", ", $values).")";		// $values can contains 'abc' or 123
 
 			$res = $this->db->query($sql);
-			if ($res === false) {
+			if (!$res) {
 				$error++;
 				if ($this->db->lasterrno() == 'DB_ERROR_RECORD_ALREADY_EXISTS') {
 					$this->errors[] = "ErrorRefAlreadyExists";
@@ -8992,7 +8992,7 @@ abstract class CommonObject
 		$this->db->begin();
 		if (!$error) {
 			$res = $this->db->query($sql);
-			if ($res === false) {
+			if (!$res) {
 				$error++;
 				$this->errors[] = $this->db->lasterror();
 			}
diff --git a/htdocs/core/db/Database.interface.php b/htdocs/core/db/Database.interface.php
index c6769ad0619..e349072ddec 100644
--- a/htdocs/core/db/Database.interface.php
+++ b/htdocs/core/db/Database.interface.php
@@ -227,7 +227,7 @@ interface Database
 	 *                            		Note that with Mysql, this parameter is not used as Myssql can already commit a transaction even if one request is in error, without using savepoints.
 	 * @param   string 	$type 			Type of SQL order ('ddl' for insert, update, select, delete or 'dml' for create, alter...)
 	 * @param	int		$result_mode	Result mode
-	 * @return  resource                Resultset of answer
+	 * @return  bool|resource			Resultset of answer or false
 	 */
 	public function query($query, $usesavepoint = 0, $type = 'auto', $result_mode = 0);
 
diff --git a/htdocs/core/db/pgsql.class.php b/htdocs/core/db/pgsql.class.php
index 7cf0a5d905a..74abf7a1e36 100644
--- a/htdocs/core/db/pgsql.class.php
+++ b/htdocs/core/db/pgsql.class.php
@@ -495,7 +495,7 @@ class DoliDBPgsql extends DoliDB
 	 * @param	int		$usesavepoint	0=Default mode, 1=Run a savepoint before and a rollback to savepoint if error (this allow to have some request with errors inside global transactions).
 	 * @param   string	$type           Type of SQL order ('ddl' for insert, update, select, delete or 'dml' for create, alter...)
 	 * @param	int		$result_mode	Result mode (not used with pgsql)
-	 * @return	false|resource			Resultset of answer
+	 * @return	bool|resource			Resultset of answer
 	 */
 	public function query($query, $usesavepoint = 0, $type = 'auto', $result_mode = 0)
 	{
diff --git a/htdocs/core/db/sqlite3.class.php b/htdocs/core/db/sqlite3.class.php
index d1d6a4b680a..10f9c021c0d 100644
--- a/htdocs/core/db/sqlite3.class.php
+++ b/htdocs/core/db/sqlite3.class.php
@@ -394,7 +394,7 @@ class DoliDBSqlite3 extends DoliDB
 	 * 									Note that with Mysql, this parameter is not used as Myssql can already commit a transaction even if one request is in error, without using savepoints.
 	 *  @param  string	$type           Type of SQL order ('ddl' for insert, update, select, delete or 'dml' for create, alter...)
 	 * @param	int		$result_mode	Result mode (not used with sqlite)
-	 *	@return	SQLite3Result			Resultset of answer
+	 *	@return	bool|SQLite3Result		Resultset of answer
 	 */
 	public function query($query, $usesavepoint = 0, $type = 'auto', $result_mode = 0)
 	{
@@ -407,6 +407,7 @@ class DoliDBSqlite3 extends DoliDB
 		$this->error = '';
 
 		// Convert MySQL syntax to SQLite syntax
+		$reg = array();
 		if (preg_match('/ALTER\s+TABLE\s*(.*)\s*ADD\s+CONSTRAINT\s+(.*)\s*FOREIGN\s+KEY\s*\(([\w,\s]+)\)\s*REFERENCES\s+(\w+)\s*\(([\w,\s]+)\)/i', $query, $reg)) {
 			// Ajout d'une clef étrangère à la table
 			// procédure de remplacement de la table pour ajouter la contrainte