mysqld 升級到8以上遇到的問題

coav4u

(1)
4 M# _! m  u. C" M  B5 vphp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)
9 K- J& V6 l: P8 I' g/ M. _
3 c& [' ^8 N. [0 y0 Jmysqli_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
原因:
. s& V; A- s+ t; y! n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:
7 |+ r% ~5 C) I- D) s2 A6 j! ~* }7 Wvi /etc/my.cnf  加入下列:
[mysqld]

6 h0 c! U. ^6 P/ l& Jcharacter-set-server=utf8
9 b6 L: Z  o& s! `( Z: c! s8 adefault_authentication_plugin=mysql_native_password
validate_password.policy=LOW
* O8 I& k2 h/ s  }; O$ s[mysql]
8 ]- \6 M  Z7 k+ Z+ mdefault-character-set=utf8

" B  M8 G" S# w  i[client]
default-character-set=utf8
, d: p+ |: O. b
/ t* J. r. \  \6 k% O- O* m- z然後重啟mysqld
7 t! c0 y( @: v' ?/ s4 eservice mysqld restart

重啟後可能須做下列動作:
mysql -u roor -p  
, C* Z7 Q& j- o" _- ?6 ]- uSHOW VARIABLES LIKE 'validate_password%';
+ N5 ^/ I6 ]# O. {SET GLOBAL validate_password_policy=LOW;ALTER USER 'root'@'localhost' IDENTIFIED WITH mysql_native_password BY '你的密碼';搞定!!

, a! `6 I5 g, r. x2 u& P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. <?
   
2. $hostname = "x.x.x.x";
   
3. $database = "db_name";
   
4. $username = "user_name";
   9 D5 D; N8 K& F0 D4 u& v
5. $password = "pwd";
   
6. 
   
7. $conn = mysqli_connect($hostname, $username, $password,$database) or trigger_error(mysql_error(),E_USER_ERROR);
   - w: {% F2 q& V$ k2 i6 y
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));
    / ~: X5 @; s0 G; ~! [! c2 s0 U
12. echo $rec['total'];
    6 h  g- e+ K' d$ H/ H  i( D, r
13. mysqli_close($conn);
    0 F* `% }3 ?, ]8 h* G( E. k& 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

! O0 b! D: U( o
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
   
2. Stack trace:
   * b: w( i. e# Q) O- {
3. #0 {main}
   & r- ~( n& i( l/ B5 K& V
4.   thrown in /test/connectmysql8.php on line 9
   ( h! }- W6 ?3 ?& }" I( j3 @
5. 
   
6. Fatal error: Uncaught Error: Call to undefined function mysqli_connect() in /test/connectmysql8.php:9
   
7. Stack trace:
   
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

- x( x4 S, |" A* m/ _
. }/ m' S' Q" a/ d[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.
說明: 千萬不能照它建議用"UTF8MB4",否則無法成功啟動
6 J. t! Y0 W2 c5 p9 E* ?9 A6 ~
(2)
2 j$ g( ?: R, e. Y( p  k(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
- q( |7 J% p9 M( J
: B2 Z; {6 K/ i" _# c(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
SELECT * 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 Q+ n, c* J! P- m4 S/ ]# a第一個錯誤需要找到Discuz!目錄中的source\class\table\table_common_usergroup.php，
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。
) s' Q) a) H6 N, B0 z
5 _+ T, s3 V! K2 S: |7 Q  T' |! O第二個錯誤需要找到Discuz!目錄下中的source\class\table\table_forum_announcement.php，
' x9 i& m/ C, K* k7 C8 X8 I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。

1 \1 Q. K, i" `3 l4 v* |5 d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。
& C3 A5 Q1 i/ o. H
. P: L& T& w0 a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。
2 q% e! K/ N% `7 \& u0 ]) 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

# R3 w. Q! O  M! w) s
- G) Z" |9 C7 m6 `: ?
' @! X- d1 E% n6 ~; w9 c