修改字段字符集 mysql 修改锁表 show processlist; 查看进程 Waiting for table metadata lock

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ALTER TABLE `question`

MODIFY COLUMN `title` varchar(50) CHARACTER SET utf8mb4 COLLATE utf8mb4_unicode_ci NOT NULL COMMENT '修改字符集为utf8mb4，兼容表情符' AFTER `sid`,
MODIFY COLUMN `content` text CHARACTER SET utf8mb4 COLLATE utf8mb4_unicode_ci NOT NULL COMMENT '问题内容' AFTER `title`;

ALTER TABLE `answer`
MODIFY COLUMN `content` text CHARACTER SET utf8mb4 COLLATE utf8mb4_unicode_ci NOT NULL COMMENT '修改字符集为utf8mb4，兼容表情符' AFTER `qid`;

修改过程中锁表

‘

修改锁表

不能写，可读

sou456执行
show processlist; ： 7247418 sou456 116.204.67.22:64059 sou456 Query 0 starting show processlist

show processlist;

Id User Host db Command Time State Info
3root127.0.0.1:61037Sleep6
59replicator11.192.74.135:62486Binlog Dump GTID716448Master has sent all binlog to slave; waiting for more updates
63event_schedulerlocalhostDaemon716448Waiting on empty queue
66system userConnect716448Waiting for master to send event
67system userConnect0Slave has read all relay log; waiting for more updates
68system userConnect716448Waiting for an event from Coordinator
69system userConnect716448Waiting for an event from Coordinator
70system userConnect716448Waiting for an event from Coordinator
71system userConnect716448Waiting for an event from Coordinator
72system userConnect716448Waiting for an event from Coordinator
73system userConnect716448Waiting for an event from Coordinator
74system userConnect716448Waiting for an event from Coordinator
75system userConnect716448Waiting for an event from Coordinator
6666579sou456116.204.67.22:62348sou456Sleep1194
7205158sou45647.93.175.119:37612sou456Query33Waiting for table metadata lockINSERT INTO answer (qid, content, created) VALUES (12639882,'明教被围攻光明顶时，杨逍他
7205159sou45647.93.175.119:37614sou456Query31Waiting for table metadata lockINSERT INTO answer (qid, content, created) VALUES (22570569,'你要注册哪里的公司，名称首
7205160sou45647.93.175.119:37620sou456Query32Waiting for table metadata lockINSERT INTO answer (qid, content, created) VALUES (8105944,'直线y=x将椭圆x^2+3y^2=6y分成两�
7205161sou45647.93.175.119:37624sou456Sleep288
7205162sou45647.93.175.119:37628sou456Sleep160
7205163sou45647.93.175.119:37630sou456Query33Waiting for table metadata lockINSERT INTO answer (qid, content, created) VALUES (21245198,'\n\n体内有病毒，打疫苗已没�
7205164sou45647.93.175.119:37634sou456Query33Waiting for table metadata lockINSERT INTO answer (qid, content, created) VALUES (21205223,'不需要很标准。而且还没达�
7205165sou45647.93.175.119:37636sou456Query36Waiting for table metadata lockINSERT INTO answer (qid, content, created) VALUES (19597350,'省内算是好点的去年校考除�
7205166sou45647.93.175.119:37644sou456Query24Waiting for table metadata lockINSERT INTO answer (qid, content, created) VALUES (10410136,'1÷（1200+1300）\n=1÷1120\n=120（�
7205167sou45647.93.175.119:37648sou456Query31Waiting for table metadata lockINSERT INTO answer (qid, content, created) VALUES (20306253,'需要除～这些茶垢都是一些金
7205168sou45647.93.175.119:37652sou456Query33Waiting for table metadata lockINSERT INTO answer (qid, content, created) VALUES (16579337,'zisedebing01 加我好友么么哒！�
7205169sou45647.93.175.119:37656sou456Query30Waiting for table metadata lockINSERT INTO answer (qid, content, created) VALUES (19813119,'中国猎头第一网云猎头网云�
7205170sou45647.93.175.119:37660sou456Query32Waiting for table metadata lockINSERT INTO answer (qid, content, created) VALUES (14752370,'家里已有的太阳能热水器和电
7205171sou45647.93.175.119:37662sou456Query30Waiting for table metadata lockINSERT INTO answer (qid, content, created) VALUES (22389438,'就算能维权我也绝不可能对自
7205172sou45647.93.175.119:37668sou456Query30Waiting for table metadata lockINSERT INTO answer (qid, content, created) VALUES (21481917,'一切没有直照的，都有可能，
7205173sou45647.93.175.119:37672sou456Sleep152
7205174sou45647.93.175.119:37676sou456Query25Waiting for table metadata lockINSERT INTO answer (qid, content, created) VALUES (18807626,'把和你提供的手机号相关绑定
7205175sou45647.93.175.119:37680sou456Query26Waiting for table metadata lockINSERT INTO answer (qid, content, created) VALUES (22571707,'专卖店好，更靠谱，有时候店
7205176sou45647.93.175.119:37684sou456Query32Waiting for table metadata lockINSERT INTO answer (qid, content, created) VALUES (21915487,'菜单---设置---禁止后台运行，
7205177sou45647.93.175.119:37688sou456Query35Waiting for table metadata lockINSERT INTO answer (qid, content, created) VALUES (22373473,'岁运并临，三刑逢冲，不论身
7205178sou45647.93.175.119:37692sou456Query33Waiting for table metadata lockINSERT INTO answer (qid, content, created) VALUES (22439945,'海水珍珠，珍珠母贝只有内层
7205179sou45647.93.175.119:37696sou456Sleep160
7205180sou45647.93.175.119:37702sou456Query29Waiting for table metadata lockINSERT INTO answer (qid, content, created) VALUES (8355248,'那可不行，小心刷不上变砖。\
7205181sou45647.93.175.119:37706sou456Sleep161
7205182sou45647.93.175.119:37710sou456Query27Waiting for table metadata lockINSERT INTO answer (qid, content, created) VALUES (18675950,'目前还没有开通南昌到万安的
7205183sou45647.93.175.119:37714sou456Sleep155
7205184sou45647.93.175.119:37718sou456Query31Waiting for table metadata lockINSERT INTO answer (qid, content, created) VALUES (21708714,'\n\n公交线路：地铁1号线，全�
7205185sou45647.93.175.119:37724sou456Query37Waiting for table metadata lockINSERT INTO answer (qid, content, created) VALUES (22126040,'\n商道枭雄 txt全集小说附件已
7205186sou45647.93.175.119:37728sou456Query32Waiting for table metadata lockINSERT INTO answer (qid, content, created) VALUES (5040365,'12月开的发票1月份是可以报销�
7205187sou45647.93.175.119:37732sou456Query31Waiting for table metadata lockINSERT INTO answer (qid, content, created) VALUES (19769818,'杭州西湖十景，除了在湖中的
7205188sou45647.93.175.119:37736sou456Query31Waiting for table metadata lockINSERT INTO answer (qid, content, created) VALUES (20947211,'2款都是真品不过相对而言下�
7205189sou45647.93.175.119:37740sou456Query33Waiting for table metadata lockINSERT INTO answer (qid, content, created) VALUES (13972030,'好望角和锦绣中华一小时30元�
7205190sou45647.93.175.119:37744sou456Sleep163
7205191sou45647.93.175.119:37746sou456Query29Waiting for table metadata lockINSERT INTO answer (qid, content, created) VALUES (20714602,'做人要诚实，真想干这行，打
7205192sou45647.93.175.119:37748sou456Query24Waiting for table metadata lockINSERT INTO answer (qid, content, created) VALUES (13722950,'技术兵好，有技术就比没技术
7205193sou45647.93.175.119:37756sou456Query38Waiting for table metadata lockINSERT INTO answer (qid, content, created) VALUES (8298037,'也被称为针距,3.50mm/3.81mm/5.00mm/
7205194sou45647.93.175.119:37758sou456Query33Waiting for table metadata lockINSERT INTO answer (qid, content, created) VALUES (22423891,'我现在就在金矿搞金矿技术工
7205195sou45647.93.175.119:37762sou456Sleep155
7205196sou45647.93.175.119:37766sou456Query25Waiting for table metadata lockINSERT INTO answer (qid, content, created) VALUES (22802318,'\n\n驾车路线：全程约128.0公里
7205197sou45647.93.175.119:37772sou456Sleep162
7205198sou45647.93.175.119:37776sou456Query32Waiting for table metadata lockINSERT INTO answer (qid, content, created) VALUES (17946519,'全自动制砖生产线的制砖工作
7205199sou45647.93.175.119:37780sou456Sleep159
7205200sou45647.93.175.119:37782sou456Query28Waiting for table metadata lockINSERT INTO answer (qid, content, created) VALUES (14329682,'有的，没有就电不到老鼠了，
7205201sou45647.93.175.119:37788sou456Query33Waiting for table metadata lockINSERT INTO answer (qid, content, created) VALUES (12291951,'太多了。去国产的公司吧。中
7205202sou45647.93.175.119:37790sou456Query27Waiting for table metadata lockINSERT INTO answer (qid, content, created) VALUES (18539477,'选择闪送，重量不重的话，3�
7205203sou45647.93.175.119:37794sou456Query33Waiting for table metadata lockINSERT INTO answer (qid, content, created) VALUES (14984492,'玉髓本就很不值钱，几十元的
7205204sou45647.93.175.119:37800sou456Query31Waiting for table metadata lockINSERT INTO answer (qid, content, created) VALUES (15807360,'\n\nNaHSO4溶于水电解出Na+ H+和S
7205205sou45647.93.175.119:37804sou456Sleep287
7205207sou45647.93.175.119:37812sou456Query24Waiting for table metadata lockINSERT INTO answer (qid, content, created) VALUES (8407840,'是纯白的衣服吗？用蓝色的墨�
7205208sou45647.93.175.119:37816sou456Query31Waiting for table metadata lockINSERT INTO answer (qid, content, created) VALUES (22168479,'展开全部\n\n\n壹拾万元叁仟叁
7205209sou45647.93.175.119:37818sou456Query29Waiting for table metadata lockINSERT INTO answer (qid, content, created) VALUES (17201988,'\n\n不属于特殊工种，跟一般�
7205210sou45647.93.175.119:37824sou456Query31Waiting for table metadata lockINSERT INTO answer (qid, content, created) VALUES (22454659,'到校报道之后吧，毕竟还要你
7205211sou45647.93.175.119:37826sou456Query32Waiting for table metadata lockINSERT INTO answer (qid, content, created) VALUES (21916452,'你好，CEA是用来诊断癌症的一
7205212sou45647.93.175.119:37832sou456Query24Waiting for table metadata lockINSERT INTO answer (qid, content, created) VALUES (19302052,'应该类似受精卵吧，如果孵化
7205213sou45647.93.175.119:37834sou456Query32Waiting for table metadata lockINSERT INTO answer (qid, content, created) VALUES (22093736,'简介：淮北市中银佳信房地产
7205214sou45647.93.175.119:37838sou456Query35Waiting for table metadata lockINSERT INTO answer (qid, content, created) VALUES (20807767,'装到脚架上，用快门线，手动
7205215sou45647.93.175.119:37842sou456Query32Waiting for table metadata lockINSERT INTO answer (qid, content, created) VALUES (20967190,'简介：注册号：****所在地：�
7205216sou45647.93.175.119:37848sou456Query32Waiting for table metadata lockINSERT INTO answer (qid, content, created) VALUES (22691597,'测绘的行业资质管理在国土局
7205217sou45647.93.175.119:37850sou456Sleep159
7205218sou45647.93.175.119:37856sou456Query25Waiting for table metadata lockINSERT INTO answer (qid, content, created) VALUES (22320865,'PC上安装MAC操作系统，硬件的�
7205219sou45647.93.175.119:37860sou456Query31Waiting for table metadata lockINSERT INTO answer (qid, content, created) VALUES (21240597,'康熙粉彩。大概二万元左右。
7205220sou45647.93.175.119:37864sou456Query33Waiting for table metadata lockINSERT INTO answer (qid, content, created) VALUES (21955440,'这里不可以放号码\n你可以去�
7205221sou45647.93.175.119:37868sou456Query33Waiting for table metadata lockINSERT INTO answer (qid, content, created) VALUES (20577875,'C.髋关节伸、膝关节伸、踝关�
7205222sou45647.93.175.119:37872sou456Query31Waiting for table metadata lockINSERT INTO answer (qid, content, created) VALUES (22202868,'鱼肉所含的蛋白质是完全蛋白
7205223sou45647.93.175.119:37876sou456Query33Waiting for table metadata lockINSERT INTO answer (qid, content, created) VALUES (18872795,'你打算找什么样的工作呢我�
7205224sou45647.93.175.119:37880sou456Sleep288
7205225sou45647.93.175.119:37884sou456Query33Waiting for table metadata lockINSERT INTO answer (qid, content, created) VALUES (22054651,'您好，感谢您对拉卡拉的关注
7205226sou45647.93.175.119:37888sou456Query27Waiting for table metadata lockINSERT INTO answer (qid, content, created) VALUES (17575594,'100多人的工厂还没有厂规，那
7205227sou45647.93.175.119:37892sou456Query31Waiting for table metadata lockINSERT INTO answer (qid, content, created) VALUES (8263635,'树木增粗，树皮加厚，采用氯�
7205228sou45647.93.175.119:37894sou456Query32Waiting for table metadata lockINSERT INTO answer (qid, content, created) VALUES (22344481,'你要是去集红堂，可以选择白
7205229sou45647.93.175.119:37900sou456Query32Waiting for table metadata lockINSERT INTO answer (qid, content, created) VALUES (22760712,'很多前扣和测扣的都是很难开
7205230sou45647.93.175.119:37902sou456Query23Waiting for table metadata lockINSERT INTO answer (qid, content, created) VALUES (18867043,'长相很重要的。道不是漂亮与
7205231sou45647.93.175.119:37908sou456Query33Waiting for table metadata lockINSERT INTO answer (qid, content, created) VALUES (22635591,'ur commitment to eachothe',1545208893),
7205232sou45647.93.175.119:37912sou456Query21Waiting for table metadata lockINSERT INTO answer (qid, content, created) VALUES (22867652,'(3-4i)(3+4i)\n=9-16i^2\n=9+16\n=25',154
7205233sou45647.93.175.119:37916sou456Query29Waiting for table metadata lockINSERT INTO answer (qid, content, created) VALUES (22064566,'你好朋友,根据你的提问,考虑�
7205234sou45647.93.175.119:37920sou456Query32Waiting for table metadata lockINSERT INTO answer (qid, content, created) VALUES (14552279,'您好您能提供给我一份吗？�
7205235sou45647.93.175.119:37924sou456Query31Waiting for table metadata lockINSERT INTO answer (qid, content, created) VALUES (14246988,'股市涨涨跌跌乃正常现象，保
7205236sou45647.93.175.119:37928sou456Query31Waiting for table metadata lockINSERT INTO answer (qid, content, created) VALUES (22685629,'温控盒子装上雾化器之后不能
7205237sou45647.93.175.119:37932sou456Query27Waiting for table metadata lockINSERT INTO answer (qid, content, created) VALUES (21764462,'现在是吞咽困难吗？专业机构
7205238sou45647.93.175.119:37934sou456Query29Waiting for table metadata lockINSERT INTO answer (qid, content, created) VALUES (20506921,'之所以说发酵是微生物的呼吸
7205239sou45647.93.175.119:37940sou456Query30Waiting for table metadata lockINSERT INTO answer (qid, content, created) VALUES (17900816,'1，剪力图正负号：使截面顺�
7205240sou45647.93.175.119:37944sou456Query31Waiting for table metadata lockINSERT INTO answer (qid, content, created) VALUES (17534131,'最简单的办法是去他临近的楼
7205241sou45647.93.175.119:37948sou456Sleep288
7205242sou45647.93.175.119:37952sou456Sleep288
7205243sou45647.93.175.119:37954sou456Sleep155
7205244sou45647.93.175.119:37958sou456Query24Waiting for table metadata lockINSERT INTO answer (qid, content, created) VALUES (22520720,'\n通辽市翰博一品有6楼以下的
7205245sou45647.93.175.119:37964sou456Query31Waiting for table metadata lockINSERT INTO answer (qid, content, created) VALUES (19922361,'Ag(NH3)2OH用于鉴别还原性基团�
7205246sou45647.93.175.119:37968sou456Sleep287
7205247sou45647.93.175.119:37972sou456Query25Waiting for table metadata lockINSERT INTO answer (qid, content, created) VALUES (14232576,'不一定，最好到银行鉴定一下
7205248sou45647.93.175.119:37976sou456Query23Waiting for table metadata lockINSERT INTO answer (qid, content, created) VALUES (16990773,'前男友住在哪里怎么了呢？？
7205249sou45647.93.175.119:37980sou456Query22Waiting for table metadata lockINSERT INTO answer (qid, content, created) VALUES (21137574,'脱发和睡眠有一定的关系\n和�
7205250sou45647.93.175.119:37984sou456Query33Waiting for table metadata lockINSERT INTO answer (qid, content, created) VALUES (22272922,'买箱子还要去淘宝，外边贵吗
7205251sou45647.93.175.119:37988sou456Query33Waiting for table metadata lockINSERT INTO answer (qid, content, created) VALUES (22662557,'对孩子用心点，别把新都放在
7205252sou45647.93.175.119:37992sou456Query36Waiting for table metadata lockINSERT INTO answer (qid, content, created) VALUES (20758030,'找个地接是很容易的事情好吧
7205253sou45647.93.175.119:37996sou456Query29Waiting for table metadata lockINSERT INTO answer (qid, content, created) VALUES (22415330,'选中车牌后,一般7个工作日就�
7205254sou45647.93.175.119:38000sou456Query32Waiting for table metadata lockINSERT INTO answer (qid, content, created) VALUES (21355345,'多吃蔬菜是关键，每顿能吃一
7205255sou45647.93.175.119:38004sou456Sleep160
7205256sou45647.93.175.119:38008sou456Query29Waiting for table metadata lockINSERT INTO answer (qid, content, created) VALUES (18947593,'\n公交线路：252路，全程约3.4�
7205257sou45647.93.175.119:38012sou456Query27Waiting for table metadata lockINSERT INTO answer (qid, content, created) VALUES (15760059,'这个给你参考：\n各国对工频�
7205279aurora11.192.74.172:52332Sleep16
7205394sou45639.107.154.222:52890sou456Query121Waiting for table metadata lockINSERT INTO answer (qid, content,created) VALUES (12748646,'不好说但是据说挺有钱赚',1545
7205606sou45639.107.154.222:56310sou456Query121Waiting for table metadata lockINSERT INTO answer (qid, content,created) VALUES (20298954,'可以的，要什么尺寸直接切。'
7205666sou45639.107.154.222:57296sou456Query120Waiting for table metadata lockINSERT INTO answer (qid, content,created) VALUES (22597748,'用代码过去吧，我就是这样的�
7205749sou45639.107.154.222:58752sou456Query121Waiting for table metadata lockINSERT INTO answer (qid, content,created) VALUES (9300737,'以科技智能与材质的精细，使�
7205867sou45639.107.154.222:32932sou456Query120Waiting for table metadata lockINSERT INTO answer (qid, content,created) VALUES (14375004,'酸是因为鸡肉在冰箱冷藏室放�
7205935sou45639.107.154.222:34150sou456Query119Waiting for table metadata lockINSERT INTO answer (qid, content,created) VALUES (20167572,'这个还是听取医生的建议吧。'
7205943sou45639.107.154.222:34438sou456Query121Waiting for table metadata lockINSERT INTO answer (qid, content,created) VALUES (15438223,'是真的，感觉不错，每天一个�
7206367sou45647.93.175.119:55246sou456Query120Waiting for table metadata lockINSERT INTO answer (qid, content,created) VALUES (22606027,'成都\n大型高二45座\n296\n105\n7:0
7206473sou45647.93.175.119:56380sou456Query121Waiting for table metadata lockINSERT INTO answer (qid, content,created) VALUES (21339575,'在11月12号，挺多老人哭了！',1
7206533sou45639.107.154.222:45856sou456Query117Waiting for table metadata lockINSERT INTO answer (qid, content,created) VALUES (18618882,'战俘列车\n二次世界大战期间�
7206610sou45639.107.154.222:47142sou456Query121Waiting for table metadata lockINSERT INTO answer (qid, content,created) VALUES (22751508,'一定要躲Q\n你的Q有延迟，不要
7206692sou45639.107.154.222:48408sou456Query117Waiting for table metadata lockINSERT INTO answer (qid, content,created) VALUES (21665129,'宋江三打祝家庄、三请：刘备�
7207012sou45647.93.175.161:39394sou456Query121Waiting for table metadata lockINSERT INTO answer (qid, content,created) VALUES (21196713,'直径:800CM=8M\ns=3.14*4*4=50.24\n\nL=3
7207110sou45647.93.175.161:40646sou456Query121Waiting for table metadata lockINSERT INTO answer (qid, content,created) VALUES (18399900,'买一个熏眼睛的眼罩效果也挺�
7207210sou45647.93.175.161:41886sou456Query121Waiting for table metadata lockINSERT INTO answer (qid, content,created) VALUES (15790011,'\n\n这还不感动那真是日了狗\n\
7207432sou45647.93.175.161:44912sou456Query117Waiting for table metadata lockINSERT INTO answer (qid, content,created) VALUES (12925677,'新能源是环保水平较高的能源�
7207833sou45647.93.175.119:55904sou456Query117Waiting for table metadata lockINSERT INTO answer (qid, content,created) VALUES (22723232,'\n\n给你也没用的，雷石歌库都
7207878sou45647.93.175.119:39636sou456Query115Waiting for table metadata lockINSERT INTO answer (qid, content,created) VALUES (20444634,'个人认为15万买标致408比东风A9
7207949sou45647.93.175.119:54542sou456Query116Waiting for table metadata lockINSERT INTO answer (qid, content,created) VALUES (21699789,'一、消费维权需要提交的证据\
7208184sou456116.204.67.22:65491sou456Query117Waiting for table metadata lockINSERT INTO answer (qid, content,created) VALUES (16924307,'光明新区实行的是开发区管委�
7208433sou456116.204.67.22:49365sou456Query118Waiting for table metadata lockINSERT INTO answer (qid, content,created) VALUES (21787659,'做传单，然后去发，在工厂区�
7208448sou456116.204.67.22:49372sou456Sleep9743
7208474sou456116.204.67.22:49378sou456Query121Waiting for table metadata lockINSERT INTO answer (qid, content,created) VALUES (5667631,'我个人反对这种“心脏记忆说�
7214452sou456116.204.67.22:50242sou456Query117Waiting for table metadata lockINSERT INTO answer (qid, content,created) VALUES (21956149,'你是需要哪种呀?国标标准的还
7214457sou456116.204.67.22:50250sou456Query122Waiting for table metadata lockINSERT INTO answer (qid, content,created) VALUES (16072952,'\n\n你好，我也需要这个音乐，
7214486sou456116.204.67.22:50260sou456Query112Waiting for table metadata lockINSERT INTO answer (qid, content,created) VALUES (10374950,'不会了.\n只能涨不能跌了.\n国�
7214879sou45639.107.154.222:47854sou456Query122Waiting for table metadata lockINSERT INTO answer (qid, content,created) VALUES (21826619,'一般三层结构的冰箱,中间零度
7215495sou456116.204.67.22:50694sou456Query103Waiting for table metadata lockINSERT INTO answer (qid, content,created) VALUES (11109623,'笔心为石墨合成的,笔杆为木头
7247418sou456116.204.67.22:64059sou456Query0startingshow processlist
7257190aurora11.192.114.100:58448Sleep2821
7257191aurora11.218.166.161:48102Sleep2818
7257192aurora11.192.114.100:58454Sleep2818
7257196aurora11.192.114.100:58461Sleep2808
7257198aurora11.218.166.161:48112information_schemaSleep2811
7257200aurora11.218.166.161:48116Sleep2809
7257203aurora11.218.166.161:48120Sleep2808
7257204aurora11.218.166.161:48122Sleep2808
7257213aurora11.192.114.100:58480Sleep2629
7257217aurora11.218.166.161:48142Sleep2126
7257225aurora11.192.114.100:58500Sleep2793
7257663sou456116.204.67.22:63110sou456Sleep2348
7257995sou456116.204.67.22:63846sou456Sleep1929
7258698sou456116.204.67.22:49773sou456Sleep1193
7258905sou456100.104.72.200:42153sou456Sleep973
7259561sou456100.104.72.200:42899sou456Query122copy to tmp tableALTER TABLE `answer`
MODIFY COLUMN `content` text CHARACTER SET utf8mb4 COLLATE utf8mb4_unicode_ci

Waiting for table metadata lock

等待元数据锁

线下数据库测试

同线上阿里rds-mysql

alter table 原理

通过复制表到临时表，来实现表字段修改；

ALTER TABLE `answer`
MODIFY COLUMN `content` text CHARACTER SET utf8mb4 COLLATE utf8mb4_unicode_ci NOT NULL COMMENT '修改字符集为utf8mb4，兼容表情符' AFTER `qid`;

show processlist;

Id User Host db Command Time State Info
4event_schedulerlocalhostDaemon523672Waiting on empty queue
4355rootDESKTOP-RVB6E5F:54581sou456Query48copy to tmp tableALTER TABLE `answer`
MODIFY COLUMN `content` text CHARACTER SET utf8mb4 COLLATE utf8mb4_unicode_ci
4358rootDESKTOP-RVB6E5F:54678Sleep10
4359rootDESKTOP-RVB6E5F:54679sou456Sleep10
4360rootDESKTOP-RVB6E5F:54681sou456Sleep9
4361rootDESKTOP-RVB6E5F:54708sou456Query0startingshow processlist