Differences

This shows you the differences between two versions of the page.

--- v5:session:session_index [2023/03/23 18:09] – Remove NOTOC dregad
+++ v5:session:session_index [2023/03/27 13:14] – [MySQL or PDO MySQL] explain reason for using binary collation dregad
@@ Line 148: / Line 148: @@
 ==== MySQL or PDO MySQL ====
-  CREATE TABLE sessions2(
+<code>
-	  sesskey VARCHAR( 64 ) NOT NULL DEFAULT '',
+CREATE TABLE sessions2 (
-	  expiry DATETIME NOT NULL ,
+  sesskey VARCHAR( 64 ) COLLATE utf8mb4_bin NOT NULL DEFAULT '',
-	  expireref VARCHAR( 250 ) DEFAULT '',
+  expiry DATETIME NOT NULL ,
-	  created DATETIME NOT NULL ,
+  expireref VARCHAR( 250 ) DEFAULT '',
-	  modified DATETIME NOT NULL ,
+  created DATETIME NOT NULL ,
-	  sessdata LONGTEXT,
+  modified DATETIME NOT NULL ,
-	  PRIMARY KEY ( sesskey ) ,
+  sessdata LONGTEXT,
-	  INDEX sess2_expiry( expiry ),
+  PRIMARY KEY ( sesskey ) ,
-	  INDEX sess2_expireref( expireref )
+  INDEX sess2_expiry( expiry ),
-  )
+  INDEX sess2_expireref( expireref )
+)
+</code>
+<WRAP info>
+When [[https://www.php.net/manual/en/session.configuration.php#ini.session.sid-bits-per-character|session.sid_bits_per_character]] php.ini setting is set to 6, the //Session ID// can contain both upper and lowercase letters.
+Collisions could occur in this case, due to MySQL performing case-insensitive searches by default.
+To avoid that, the //sesskey// column should use binary (or a case-sensitive) collation.
+</WRAP>
 ==== PostgreSQL ====