mysqld 升級到8以上遇到的問題

coav4u

(1)
, ~4 \2 M5 J( E2 |* K* `* Rphp連到mysql出現2行errors : (discuz網頁出現的是連接到mysql錯誤表格,需自行寫一隻連接mysql的php程式來測試)
: [) l! U+ P6 w# W0 x4 G# i* B, f
3 g! u) d9 z( Tmysqli_real_connect(): Server sent charset (255) unknown to the client. Please, report to the developers
mysqli_real_connect(): (HY000/2054): Server sent charset unknown to the client. Please, report to the developers
: W4 t6 @# g6 Q原因:
$ R; z+ B4 [+ m  K+ S在MySQL 8.0.21中，caching_sha2_password是默認的身份驗證插件，而不是以往的mysql_native_password。所以和php不相容。可以降級php，也可以修改MySQL的配置。 吾人決定修改MySQL的配置:
, f0 J% Y4 d& R6 I1 ?8 ?vi /etc/my.cnf  加入下列:
% B  z( x7 A" S  i9 Q[mysqld]
4 Q9 O( `' I2 k8 k' p" A
& e: Z# ]7 i. l( R: |% Xcharacter-set-server=utf8
default_authentication_plugin=mysql_native_password
( l5 R; d5 m) j) `validate_password.policy=LOW
) _7 J& I  P! R; C$ Q. A2 c[mysql]
default-character-set=utf8

[client]
default-character-set=utf8
/ S( b3 y# S  g7 [/ ~7 V9 Q- J  l. u
然後重啟mysqld
service mysqld restart

, Q5 v* K8 R/ C0 u重啟後可能須做下列動作:
: _+ E  t9 i4 q2 n0 w9 kmysql -u roor -p  
SHOW VARIABLES LIKE 'validate_password%';
SET GLOBAL validate_password_policy=LOW;ALTER USER 'root'@'localhost' IDENTIFIED WITH mysql_native_password BY '你的密碼';搞定!!

註: mysqld啟動時,在/var/log/mysql/mysqld.log紀錄著:註: 可以先寫支php程式以測試 ~~~

1. <?
   8 n3 Y) P' l; v
2. $hostname = "x.x.x.x";
   2 n  u' C% d9 z$ R( N
3. $database = "db_name";
   
4. $username = "user_name";
   
5. $password = "pwd";
   3 w3 w& S) Y7 K8 @6 b; s9 y. q
6. 
   , |1 u3 q/ o! w  v
7. $conn = mysqli_connect($hostname, $username, $password,$database) or trigger_error(mysql_error(),E_USER_ERROR);
   
8. mysqli_query($conn ,"SET NAMES utf8");
   
9. 
   
10. $sql = "select count(*) as total from " .  "table_name";
    
11. $rec = mysqli_fetch_assoc(mysqli_query( $conn,$sql));
    
12. echo $rec['total'];
    & w/ @: |8 I; @% r! z
13. mysqli_close($conn);
    / s0 e, n2 D' w3 b% \
14. ?>

複製代碼

遊客，本帖隱藏的內容需要積分高於 999999999999 才可瀏覽，您當前積分為 0

5 r' ]* H0 `- q9 O2 ]9 Y3 E

當php 7.2.24  connect to mysql server,出現 :

1. PHP Fatal error:  Uncaught Error: Call to undefined function mysqli_connect() in /test/connectmysql8.php:9
   $ l% w" B* A9 b9 ^" a
2. Stack trace:
   
3. #0 {main}
   
4.   thrown in /test/connectmysql8.php on line 9
   
5. 
   
6. Fatal error: Uncaught Error: Call to undefined function mysqli_connect() in /test/connectmysql8.php:9
     G% D. [8 g; ?
7. Stack trace:
   & N) y" s1 m: y4 u. C# U
8. #0 {main}
   
9.   thrown in /test/connectmysql8.php on line 9

複製代碼

這是版本相依的問題,只要 yum install php-mysqlnd  或 yum install php-mysqli 即可

5 W9 x$ v' i. f5 z0 N- B
" n5 ]1 \  O+ V! i; X[Warning] [MY-013242] [Server] --character-set-server: 'utf8' is currently an alias for the character set UTF8MB3, but will be an alias for UTF8MB4 in a future release. Please consider using UTF8MB4 in order to be unambiguous.
' N( Z. g; `5 I說明: 千萬不能照它建議用"UTF8MB4",否則無法成功啟動

(2)
(1064) You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near 'system>0' at line 1
SELECT COUNT(*) FROM common_usergroup WHERE type='special' and system>0
9 ]" ?# g4 q9 W/ b' V' i' G$ ]
(1064) You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near 'groups = '' AND starttime<=1532077291 AND (endtime>=1532077291 OR endtime=0) ORD' at line 1
4 C9 |8 E4 z! s. O  PSELECT * FROM forum_announcement WHERE type!=2 AND groups = '' AND starttime<=1532077291 AND (endtime>=1532077291 OR endtime=0) ORDER BY displayorder, starttime DESC, id DESC LIMIT 1

因為MySQL 8.0+將system和groups作為了關鍵字，所以不能直接在SQL中將system和groups這兩個詞作為數據庫、數據表、數據表字段中的任意一種使用，如果數據庫名或數據表名或數據表字段名使用了system或groups作為名字，必須使用一對反引號引用起來。寫作`system`或`groups`。
8 g* o( b4 l+ D1 d1 V
第一個錯誤需要找到Discuz!目錄中的source\class\table\table_common_usergroup.php，
" D; E9 U# z$ \  Z! }7 D將文件中所有的system全部改成`system`，保存後重新上傳到服務器的相同目錄即可。
, ]$ ~& O3 p; S' c8 U8 h
第二個錯誤需要找到Discuz!目錄下中的source\class\table\table_forum_announcement.php，
2 X0 \$ x4 q; b0 z! ^7 P2 m將文件中所有的groups全部改為`groups`，保存後重新上傳到服務器的相同目錄即可。

如果在MySQL 8+環境下安裝Discuz!，在安裝前需要給install\data\install.sql文件中沒有加引號的所有system逐一添加一對反引號保存重新上傳到服務器的相同目錄，否則也會出現SQL語法錯誤。

, J& ~1 K( X2 i& q; B! I為了避免語法錯誤，在寫SQL語句時，一定要為所有的數據庫名、數據表名、數據表字段名全部添加一對反引號，像Discuz!這樣的寫法是很不妥的。
$ Y" |/ K7 H! I) v, |& _以上參考:   升級到 MySQL 8.0+ 後Discuz! 更新緩存時出現SQL語法錯誤



) Y# Y  M3 k/ m) \