WordPress数据库错误:Lost connection to MySQL server

问题描述：

PHP message: WordPress数据库 xxx… 发生 Lost connection to MySQL server during query错误，这是由 xxx ….。

其他表现，访问网页时提示： 建立数据库连接时出错 。

问题原因：

通常是因为数据库软件跟数据库本身版本不匹配导致，比如数据库软件升级，或者数据库迁移，这时候，某些表结构发生变化，从而导致访问数据库出错。

打开/var/lib/mysql/xxx.err文件，通常会发现如下内容：

[ERROR] mysqld: Table './dbname/wp_options' is marked as crashed and should be repaired [Warning] Checking table:   './dbname/wp_options' [ERROR] mysqld: Table './dbname/wp_users' is marked as crashed and should be repaired [Warning] Checking table:   './dbname/wp_users' 。。。。。

解决方案：

解决方案通常是通过mysql_upgrade检查修复数据库中的表。示例如下：

[root@vimsky ~]# mysql_upgrade -u root -p
Enter password:  
Phase 1/4: Fixing views 
Phase 2/4: Fixing table and database names 
Phase 3/4: Checking and upgrading tables Processing databases information_schema mywordpressblogsDB 
mywordpressblogsDB.wp_commentmeta                            OK 
mywordpressblogsDB.wp_comments                               OK 
mywordpressblogsDB.wp_cptch_images                           OK 
mywordpressblogsDB.wp_cptch_packages                         OK 
mywordpressblogsDB.wp_cptch_whitelist                        OK 
mywordpressblogsDB.wp_gravatars                              OK 
mywordpressblogsDB.wp_links                                  OK 
mywordpressblogsDB.wp_options                                OK 
mywordpressblogsDB.wp_postmeta                               OK 
mywordpressblogsDB.wp_posts                                  OK 
mywordpressblogsDB.wp_supsystic_tbl_columns                  OK 
mywordpressblogsDB.wp_supsystic_tbl_diagrams                 OK 
mywordpressblogsDB.wp_supsystic_tbl_rows                     OK 
mywordpressblogsDB.wp_supsystic_tbl_tables                   OK 
mywordpressblogsDB.wp_term_relationships                     OK 
mywordpressblogsDB.wp_term_taxonomy                          OK 
mywordpressblogsDB.wp_termmeta                               OK 
mywordpressblogsDB.wp_terms                                  OK 
mywordpressblogsDB.wp_usermeta                               OK 
mywordpressblogsDB.wp_users                                  OK 
mywordpressblogsDB.wp_wp_rp_tags                             OK 
mysql mysql.columns_priv                                 OK 
mysql.db                                           OK 
mysql.event                                        OK 
mysql.func                                         OK 
mysql.help_category                                OK 
mysql.help_keyword                                 OK 
mysql.help_relation                                OK 
mysql.help_topic                                   OK 
mysql.host                                         OK 
mysql.ndb_binlog_index                             OK 
mysql.plugin                                       OK 
mysql.proc                                         OK 
mysql.procs_priv                                   OK 
mysql.proxies_priv                                 OK 
mysql.servers                                      OK 
mysql.tables_priv                                  OK 
mysql.time_zone                                    OK 
mysql.time_zone_leap_second                        OK 
mysql.time_zone_name                               OK 
mysql.time_zone_transition                         OK 
mysql.time_zone_transition_type                    OK 
mysql.user                                         OK 
performance_schema test Phase 4/4: Running 'mysql_fix_privilege_tables' OK 
[root@vimsky ~]#