Question

我有一个有两列的表。

第一列有一个日期列表，第二列有一个日期列表。

ERROR in ./libs/ample-admin/ampleadmin-minimal/less/common.less
Module build failed: ModuleNotFoundError: Module not found: Error: Can't resolve './icons/font-awesome/less/icons/font-awesome/fonts/fontawesome-webfont.eot' in '/home/sujeet/projects/src/module-front/libs/ample-admin/ampleadmin-minimal/less'
    at factoryCallback (/home/sujeet/projects/src/module-front/node_modules/webpack/lib/Compilation.js:276:40)
    at factory (/home/sujeet/projects/src/module-front/node_modules/webpack/lib/NormalModuleFactory.js:237:20)
    at resolver (/home/sujeet/projects/src/module-front/node_modules/webpack/lib/NormalModuleFactory.js:60:20)
    at asyncLib.parallel.e (/home/sujeet/projects/src/module-front/node_modules/webpack/lib/NormalModuleFactory.js:127:20)
    at /home/sujeet/projects/src/module-front/node_modules/async/dist/async.js:3874:9
    at /home/sujeet/projects/src/module-front/node_modules/async/dist/async.js:473:16
    at iteratorCallback (/home/sujeet/projects/src/module-front/node_modules/async/dist/async.js:1048:13)
    at /home/sujeet/projects/src/module-front/node_modules/async/dist/async.js:958:16
    at /home/sujeet/projects/src/module-front/node_modules/async/dist/async.js:3871:13
    at resolvers.normal.resolve (/home/sujeet/projects/src/module-front/node_modules/webpack/lib/NormalModuleFactory.js:119:22)
    at onError (/home/sujeet/projects/src/module-front/node_modules/enhanced-resolve/lib/Resolver.js:65:10)
    at loggingCallbackWrapper (/home/sujeet/projects/src/module-front/node_modules/enhanced-resolve/lib/createInnerCallback.js:31:19)
    at runAfter (/home/sujeet/projects/src/module-front/node_modules/enhanced-resolve/lib/Resolver.js:158:4)
    at innerCallback (/home/sujeet/projects/src/module-front/node_modules/enhanced-resolve/lib/Resolver.js:146:3)
    at loggingCallbackWrapper (/home/sujeet/projects/src/module-front/node_modules/enhanced-resolve/lib/createInnerCallback.js:31:19)
    at next (/home/sujeet/projects/src/module-front/node_modules/tapable/lib/Tapable.js:252:11)
    at /home/sujeet/projects/src/module-front/node_modules/enhanced-resolve/lib/UnsafeCachePlugin.js:40:4
    at loggingCallbackWrapper (/home/sujeet/projects/src/module-front/node_modules/enhanced-resolve/lib/createInnerCallback.js:31:19)
    at runAfter (/home/sujeet/projects/src/module-front/node_modules/enhanced-resolve/lib/Resolver.js:158:4)
    at innerCallback (/home/sujeet/projects/src/module-front/node_modules/enhanced-resolve/lib/Resolver.js:146:3)
    at loggingCallbackWrapper (/home/sujeet/projects/src/module-front/node_modules/enhanced-resolve/lib/createInnerCallback.js:31:19)
    at next (/home/sujeet/projects/src/module-front/node_modules/tapable/lib/Tapable.js:252:11)
    at innerCallback (/home/sujeet/projects/src/module-front/node_modules/enhanced-resolve/lib/Resolver.js:144:11)
    at loggingCallbackWrapper (/home/sujeet/projects/src/module-front/node_modules/enhanced-resolve/lib/createInnerCallback.js:31:19)
    at next (/home/sujeet/projects/src/module-front/node_modules/tapable/lib/Tapable.js:249:35)
    at resolver.doResolve.createInnerCallback (/home/sujeet/projects/src/module-front/node_modules/enhanced-resolve/lib/DescriptionFilePlugin.js:44:6)
    at loggingCallbackWrapper (/home/sujeet/projects/src/module-front/node_modules/enhanced-resolve/lib/createInnerCallback.js:31:19)
    at afterInnerCallback (/home/sujeet/projects/src/module-front/node_modules/enhanced-resolve/lib/Resolver.js:168:10)
    at loggingCallbackWrapper (/home/sujeet/projects/src/module-front/node_modules/enhanced-resolve/lib/createInnerCallback.js:31:19)
    at next (/home/sujeet/projects/src/module-front/node_modules/tapable/lib/Tapable.js:252:11)
 @ ./libs/ample-admin/ampleadmin-minimal/less/common.less
 @ ./src/apps/home/home.app.js

我希望这两列能够计算出20天的日期，以获得2018/01/21并进入第3列。如何做到这一点，所以每次使用新行更新表时，它会自动将两者放在一起。

Answer 1

在MySQL 5.7.something +中，您可以创建一个生成的列：

alter table t add (col1 + interval col2 day);

在早期版本中，您可以使用视图：

create view v_t as
    select t.*, (col1 + interval col2 day) as col3
    from t;

MySQL - 自动添加第3列中的日期天数

1 个答案: