常連

注目の的

社会貢献

質問力

React.FC型を使用するメリットは何でしょうか？
例えば以下の①と②の違いは何でしょうか？

```
type SeachFormProps = {
    productId: string,
    fromDate: string,
    toDate: string,
}

// ①
const SeachForm: Function = (props: SeachFormProps) => {

// ②
const SeachForm: React.FC<SeachFormProps> = (props) => {
```

React.FC型を使用するメリット

Go初心者です。
勉強のために `Echo` `GORM`を使ったAPIを作っています。

ただいま usersテーブル に入っているレコードをパラメータで送られたきた id から一つ特定して取得する処理を書いています。 Railsでいう users_contoroller の `show`アクションのような処理を作りたいです。
しかし、１回目の`GET`では成功するクエリが2回目以降失敗してしまい困っています。(下記で説明)
どなたか解決策をご教授頂けますと幸いですm(_ _)m


ディレクトリ構造は以下のようになります

```
.
|-- controllers
|   `-- users.go
|-- db
|   `-- connect.go
|-- main.go
`-- models
    `-- user.go
```

各ファイルのは以下のようになっています。

↓ main.go
```
package main

import (
	"github.com/labstack/echo"
	"github.com/labstack/echo/middleware"
	"echo_first/controllers"
)

func main() {
	e := echo.New()
	e.Use(middleware.Logger())
	e.Use(middleware.Recover())

	// ルーティング
	e.GET("user/:id", users_controller.Show())

	// サーバー起動
	e.Logger.Fatal(e.Start(":3000"))
}

```

↓ models/user.go
```
package model

type User struct {
	Id int
	Name string
	Birth_day int
}
```

↓ db/connect.go
```
package dbconnect

import (
  "github.com/jinzhu/gorm"
	_ "github.com/jinzhu/gorm/dialects/mysql"
	"fmt"
)

func Connect() *gorm.DB{
	db, err := gorm.Open("mysql", "hogeuser:@/hogehoge?charset=utf8&parseTime=True&loc=Local")

	if err != nil {
		fmt.Print("データベース接続に失敗しました。")
	}
	db.LogMode(true)
	return db
}

```

↓ conrollers/user.go
```
package users_controller

import (
	"github.com/labstack/echo"
	"net/http"
	"fmt"
	"echo_first/models"
	"echo_first/db"
)


func Show() echo.HandlerFunc{
	db := dbconnect.Connect()
	user := new(model.User)
	return func(c echo.Context) error{
		user_id := c.Param("id")
		result := db.First(&user, "id = ?", user_id)
		if result.RecordNotFound() {
			fmt.Println("レコードが見つかりません")
		}
		return c.JSON(http.StatusOK, result)
	}
}
```



サーバーを起動立ち上げ１回目のGETリクエスト `user/1`では以下のようにデータを取得できます。
```
[25.45ms]  SELECT * FROM `users`  WHERE (id = '1') ORDER BY `users`.`id` ASC LIMIT 1  
[1 rows affected or returned ]
```

しかし２回目のGETリクエスト `user/2`ではSQLがおかしく、データを取得できません。
```
[29.71ms]  SELECT * FROM `users`  WHERE `users`.`id` = 1 AND ((id = '2')) ORDER BY `users`.`id` ASC LIMIT 1  
[0 rows affected or returned ] 
レコードが見つかりません
```

データベースのコネクションの問題なのか、GORMのクエリの問題なのか分からず躓いてしまいました。
データベースのコネクションの問題の場合はどこで db.Closeするのか分かりません...。リクエストの度にデータベースに接続して Closeする？？のでしょうか。。
どなたかご教授お願い致します（ ;  ; ）

[Go] echo, GORMを使ったREST API実装についての質問

### 前提・実現したいこと

下記サイトを参考にlaravel-adminのインストールを試みましたが、
[https://tac-blog.tech/index.php/2018/09/24/install-laravel-admin/](https://tac-blog.tech/index.php/2018/09/24/install-laravel-admin/)

php artisan admin:install
とするとエラーが発生します。

お分かりになる方教えていただければ幸いです。
何卒宜しくお願い致します。

### 発生している問題・エラーメッセージ

```
/httpdocs/laravel$ php artisan admin:install

In Connection.php line 664:
                                                                               
  could not find driver (SQL: select * from information_schema.tables where t  
  able_schema = homestead and table_name = migrations)                         
                                                                               

In PDOConnection.php line 47:
                         
  could not find driver  
                         

In PDOConnection.php line 43:
                         
  could not find driver  
                         

```



### 試したこと

.envの設定は下記になっています。

DB_CONNECTION=mysql
DB_HOST=localhost
DB_PORT=3306
DB_DATABASE=laravel
DB_USERNAME=laravel_user
DB_PASSWORD=pass

phpinfoは下記になっています。

PDO drivers	mysql, odbc, pgsql, sqlite
pdo_mysql	mysqlnd 5.0.12-dev - 20150407 - $Id: d8daadaf41e3cd81d7c6ae96c6091fd15b2c9382 $

### 補足情報（FW/ツールのバージョンなど）

サーバー：GMOクラウド VPS
Laravel Framework 5.5.48
php 7.1.0
mysql  Ver 15.1 Distrib 5.5.52-MariaDB, for Linux (x86_64) using readline 5.1

laravel-adminインストール時エラーが起きます。

### はじめに

React + Redux + Material-UI で簡単なアプリケーションを開発しています。
現在はMaterial-UIのDrawerを実装しているのですが、
connect()でComponentに渡した関数を使用すると下記のようなエラーが発生します。
どなたかご教授お願い致します。


### 発生している問題・エラーメッセージ

```
TypeError: this.props.handleToggleDrawer is not a function
onClick
src/components/header/NavIcon.js:79
  76 | <IconButton
  77 |     color="inherit"
  78 |     aria-label="Menu"
> 79 |     onClick={() => this.props.handleToggleDrawer()}
  80 | ^   className={classes.navIcon}
  81 | >
  82 |     <MenuIcon />
```

### 該当のソースコード

```actions/NavIconAction
/**
 * action/NavIconAction.js
 */
import { TOGGLE_DRAWER } from "../utils/actionTypes";

export const toggleDrawer = () => {
    return {
        type: TOGGLE_DRAWER,
    }
}
```


```reducer
/**
 * reducers/NavIconReducer.js
 */
import * as actionTypes from '../utils/actionTypes'

const initialState = {
    open: false,
}

export default function NavIconReducer(state = initialState, action) {
    switch (action.type) {
        case actionTypes.TOGGLE_DRAWER:
            console.log('open: ' + !state.open)
            return Object.assign({}, state, {
                open: !state.open,
            })
        default:
            return state
    }
}
```


```reducer/index.js
/**
 * reducers/index.js
 */
import { combineReducers } from 'redux';
import NavIconReducer from './NavIconReducer';
import ShareIconReducer from './ShareIconReducer';
import NotificationReducer from './NotificationReducer';

const reducers = combineReducers({
    NavIconReducer,
    ShareIconReducer,
    NotificationReducer
});

export default reducers;
```


```container
/**
 * containers/NavIconContainer.js
 */
import { connect } from 'react-redux';
import { toggleDrawer } from '../actions/NavIconAction'
import NavIcon from '../components/header/NavIcon'

const mapStateToProps = state => ({
    open: state.NavIconReducer.open,
})

const mapDispatchToProps = dispatch => {
    return{
        handleToggleDrawer: () => dispatch(toggleDrawer())
    }
}

export default connect(mapStateToProps, mapDispatchToProps)(NavIcon)
```


```component
/**
 * components/header/NavIcon.js
 */
import React from 'react'
import { withStyles } from '@material-ui/core/styles'
import MenuIcon from '@material-ui/icons/Menu'
import Hidden from '@material-ui/core/Hidden'
import Drawer from '@material-ui/core/Drawer'
import Divider from '@material-ui/core/Divider'
import List from '@material-ui/core/List'
import ListItem from '@material-ui/core/ListItem'
import ListItemText from '@material-ui/core/ListItemText'
import InfoIcon from '@material-ui/icons/Info';
import HomeIcon from '@material-ui/icons/Home';
import AccountCircle from '@material-ui/icons/AccountCircle';
import LockOpen from '@material-ui/icons/LockOpen';
import HowToReg from '@material-ui/icons/HowToReg';
import { ListItemIcon } from '@material-ui/core';
import IconButton from '@material-ui/core/IconButton';

const drawerWidth = 250 // Width for Drawer

const styles = theme => ({
    navIcon: {
        [theme.breakpoints.up('md')]: {
            display: 'none',
        },
    },
    drawer: {
    },
    drawerPaper: {
        width: drawerWidth,
    },
});

class NavIcon extends React.Component {
    render() {
        const { theme, classes } = this.props

        const drawer = (
            <div>
                <Divider />
                <List>
                    <ListItem button>
                        <ListItemIcon><InfoIcon /></ListItemIcon>
                        <ListItemText primary="***** とは" />
                    </ListItem>
                </List>
                <Divider />
                <List>
                    <ListItem button>
                        <ListItemIcon><HomeIcon /></ListItemIcon>
                        <ListItemText primary="トップページ" />
                    </ListItem>
                </List>
                <List>
                    <ListItem button>
                        <ListItemIcon><AccountCircle /></ListItemIcon>
                        <ListItemText primary="マイページ" />
                    </ListItem>
                </List>
                <List>
                    <ListItem button>
                        <ListItemIcon><LockOpen /></ListItemIcon>
                        <ListItemText primary="ログイン" />
                    </ListItem>
                </List>
                <List>
                    <ListItem button>
                        <ListItemIcon><HowToReg /></ListItemIcon>
                        <ListItemText primary="新規会員登録" />
                    </ListItem>
                </List>
            </div>
        )

        return (
            <div>
                <IconButton
                    color="inherit"
                    aria-label="Menu"
                    onClick={() => this.props.handleToggleDrawer()}
                    className={classes.navIcon}
                >
                    <MenuIcon />
                </IconButton>
                <nav className={classes.drawer} aria-label="link">
                    <Hidden mdUp> {/* md未満 */}
                        <Drawer
                            variant="temporary"
                            anchor={theme.direction === 'rtl' ? 'right' : 'left'}
                            open={this.props.open}
                            onClose={() => this.props.handleToggleDrawer()}
                            classes={{
                                paper: classes.drawerPaper,
                            }}
                            ModalProps={{
                                keepMounted: true, // Better open performance on mobile.
                            }}
                        >
                            {drawer}
                        </Drawer>
                    </Hidden>
                    <Hidden smDown implementation="css"> {/* md以上 */}
                        <Drawer
                            variant="permanent"
                            open
                            classes={{
                                paper: classes.drawerPaper,
                            }}
                        >
                            {drawer}
                        </Drawer>
                    </Hidden>
                </nav>
            </div>
        )
    }
}

export default withStyles(styles, { withTheme: true })(NavIcon)
```



```
/**
 * components/header/index.js
 */
import React from 'react'
import { withStyles } from '@material-ui/core/styles'
import AppBar from '@material-ui/core/AppBar'
import Toolbar from '@material-ui/core/ToolBar'
import Typography from '@material-ui/core/Typography';
import NavIcon from './NavIcon'
import ShareIcon from './ShareIcon'
import logo from '../../logo.png'

const drawerWidth = 250 // Width for Drawer

const styles = theme => ({
    appBar: {
        width: '100%',
        marginLeft: drawerWidth,
        [theme.breakpoints.up('md')]: {
            width: `calc(100% - ${drawerWidth}px)`,
        },
    },
    toolBar: {
    },
    title: {
        margin: 'auto',
    },
    logo: {
        width: 20,
        paddingRight: 5,
    },
})

const Header = ({ classes }) => (
    <div className={classes.header}>
        <AppBar className={classes.appBar}>
            <Toolbar className={classes.toolBar}>
                <NavIcon />
                <Typography className={classes.title}>
                    <img src={logo} alt="Header logo" className={classes.logo} />
                    ぐるめなう
                </Typography>
            </Toolbar>
        </AppBar>
    </div>
)

export default withStyles(styles, { withTheme: true })(Header)
```



```App
/**
 * App.js
 */
import React from 'react';
import { Route, Switch } from 'react-router-dom'
import { makeStyles } from '@material-ui/core/styles'
import CssBaseline from '@material-ui/core/CssBaseline'
import Header from './components/header'
import About from './components/about'
import Top from './components/top'
import MyPage from './components/mypage'
import Login from './components/login'
import Signup from './components/signup'

const useStyles = makeStyles(() => ({
    root: {
    },
}))

function App() {
    const classes = useStyles();

    return (
        <CssBaseline>
            <div className={classes.root}>
                <Header />
                <Switch>
                    <Route exact path="/" component={Top} />
                    <Route exact path="/mypage" component={MyPage} />
                    <Route exact path="/login" component={Login} />
                    <Route exact path="/signup" component={Signup} />
                    <Route exact path="/about" component={About} />
                </Switch>
            </div>
        </CssBaseline>
    );
}

export default App;
```

```index.js
/**
 * index.js
 */
import React from 'react'
import ReactDOM from 'react-dom'
import { Provider } from 'react-redux';
import App from './App'
import { createStore } from 'redux';
import reducers from './reducers';

const store = createStore(reducers)

ReactDOM.render(
    <Provider store={store}>
        <App />
    </Provider>,
    document.getElementById('root')
)
```

### 試したこと

MenuIconをクリックすると上記のエラーが発生します。

React+Redux+Material-UI error : is not a function

### 前提・実現したいこと

Dockerでlaravelの環境を構築するのに、" php artisan migrate " をすると以下のエラーが起こってしまいます。

### 発生している問題・エラーメッセージ

```
   Illuminate\Database\QueryException  : SQLSTATE[HY000] [1045] Access denied for user 'default'@'172.19.0.5' (using password: YES) (SQL: select * from information_schema.tables where table_schema = default and table_name = migrations and table_type = 'BASE TABLE')

  at /var/www/vendor/laravel/framework/src/Illuminate/Database/Connection.php:665
    661|         // If an exception occurs when attempting to run a query, we'll format the error
    662|         // message to include the bindings with SQL, which will make this exception a
    663|         // lot more helpful to the developer instead of just the database's errors.
    664|         catch (Exception $e) {
  > 665|             throw new QueryException(
    666|                 $query, $this->prepareBindings($bindings), $e
    667|             );
    668|         }
    669| 

  Exception trace:

  1   PDOException::("SQLSTATE[HY000] [1045] Access denied for user 'default'@'172.19.0.5' (using password: YES)")
      /var/www/vendor/laravel/framework/src/Illuminate/Database/Connectors/Connector.php:70

  2   PDO::__construct("mysql:host=mysql;port=3306;dbname=default", "default", "root", [])
      /var/www/vendor/laravel/framework/src/Illuminate/Database/Connectors/Connector.php:70

  3   Illuminate\Database\Connectors\Connector::createPdoConnection("mysql:host=mysql;port=3306;dbname=default", "default", "root", [])
      /var/www/vendor/laravel/framework/src/Illuminate/Database/Connectors/Connector.php:46

  4   Illuminate\Database\Connectors\Connector::createConnection("mysql:host=mysql;port=3306;dbname=default", [])
      /var/www/vendor/laravel/framework/src/Illuminate/Database/Connectors/MySqlConnector.php:24

  5   Illuminate\Database\Connectors\MySqlConnector::connect()
      /var/www/vendor/laravel/framework/src/Illuminate/Database/Connectors/ConnectionFactory.php:182

  6   Illuminate\Database\Connectors\ConnectionFactory::Illuminate\Database\Connectors\{closure}()
      /var/www/vendor/laravel/framework/src/Illuminate/Database/Connection.php:920

  7   call_user_func(Object(Closure))
      /var/www/vendor/laravel/framework/src/Illuminate/Database/Connection.php:920

  8   Illuminate\Database\Connection::getPdo()
      /var/www/vendor/laravel/framework/src/Illuminate/Database/Connection.php:945

  9   Illuminate\Database\Connection::getReadPdo()
      /var/www/vendor/laravel/framework/src/Illuminate/Database/Connection.php:400

  10  Illuminate\Database\Connection::getPdoForSelect()
      /var/www/vendor/laravel/framework/src/Illuminate/Database/Connection.php:326

  11  Illuminate\Database\Connection::Illuminate\Database\{closure}("select * from information_schema.tables where table_schema = ? and table_name = ? and table_type = 'BASE TABLE'")
      /var/www/vendor/laravel/framework/src/Illuminate/Database/Connection.php:658

  12  Illuminate\Database\Connection::runQueryCallback("select * from information_schema.tables where table_schema = ? and table_name = ? and table_type = 'BASE TABLE'", Object(Closure))
      /var/www/vendor/laravel/framework/src/Illuminate/Database/Connection.php:625

  13  Illuminate\Database\Connection::run("select * from information_schema.tables where table_schema = ? and table_name = ? and table_type = 'BASE TABLE'", Object(Closure))
      /var/www/vendor/laravel/framework/src/Illuminate/Database/Connection.php:334

  14  Illuminate\Database\Connection::select("select * from information_schema.tables where table_schema = ? and table_name = ? and table_type = 'BASE TABLE'")
      /var/www/vendor/laravel/framework/src/Illuminate/Database/Schema/MySqlBuilder.php:18

  15  Illuminate\Database\Schema\MySqlBuilder::hasTable("migrations")
      /var/www/vendor/laravel/framework/src/Illuminate/Database/Migrations/DatabaseMigrationRepository.php:169

  16  Illuminate\Database\Migrations\DatabaseMigrationRepository::repositoryExists()
      /var/www/vendor/laravel/framework/src/Illuminate/Database/Migrations/Migrator.php:585

  17  Illuminate\Database\Migrations\Migrator::repositoryExists()
      /var/www/vendor/laravel/framework/src/Illuminate/Database/Console/Migrations/MigrateCommand.php:91

  18  Illuminate\Database\Console\Migrations\MigrateCommand::prepareDatabase()
      /var/www/vendor/laravel/framework/src/Illuminate/Database/Console/Migrations/MigrateCommand.php:63

  19  Illuminate\Database\Console\Migrations\MigrateCommand::handle()
      /var/www/vendor/laravel/framework/src/Illuminate/Container/BoundMethod.php:32

  20  call_user_func_array([])
      /var/www/vendor/laravel/framework/src/Illuminate/Container/BoundMethod.php:32

  21  Illuminate\Container\BoundMethod::Illuminate\Container\{closure}()
      /var/www/vendor/laravel/framework/src/Illuminate/Container/BoundMethod.php:90

  22  Illuminate\Container\BoundMethod::callBoundMethod(Object(Illuminate\Foundation\Application), Object(Closure))
      /var/www/vendor/laravel/framework/src/Illuminate/Container/BoundMethod.php:34

  23  Illuminate\Container\BoundMethod::call(Object(Illuminate\Foundation\Application), [])
      /var/www/vendor/laravel/framework/src/Illuminate/Container/Container.php:591

  24  Illuminate\Container\Container::call()
      /var/www/vendor/laravel/framework/src/Illuminate/Console/Command.php:192

  25  Illuminate\Console\Command::execute(Object(Symfony\Component\Console\Input\ArgvInput), Object(Illuminate\Console\OutputStyle))
      /var/www/vendor/symfony/console/Command/Command.php:255

  26  Symfony\Component\Console\Command\Command::run(Object(Symfony\Component\Console\Input\ArgvInput), Object(Illuminate\Console\OutputStyle))
      /var/www/vendor/laravel/framework/src/Illuminate/Console/Command.php:179

  27  Illuminate\Console\Command::run(Object(Symfony\Component\Console\Input\ArgvInput), Object(Symfony\Component\Console\Output\ConsoleOutput))
      /var/www/vendor/symfony/console/Application.php:915

  28  Symfony\Component\Console\Application::doRunCommand(Object(Illuminate\Database\Console\Migrations\MigrateCommand), Object(Symfony\Component\Console\Input\ArgvInput), Object(Symfony\Component\Console\Output\ConsoleOutput))
      /var/www/vendor/symfony/console/Application.php:272

  29  Symfony\Component\Console\Application::doRun(Object(Symfony\Component\Console\Input\ArgvInput), Object(Symfony\Component\Console\Output\ConsoleOutput))
      /var/www/vendor/symfony/console/Application.php:148

  30  Symfony\Component\Console\Application::run(Object(Symfony\Component\Console\Input\ArgvInput), Object(Symfony\Component\Console\Output\ConsoleOutput))
      /var/www/vendor/laravel/framework/src/Illuminate/Console/Application.php:90

  31  Illuminate\Console\Application::run(Object(Symfony\Component\Console\Input\ArgvInput), Object(Symfony\Component\Console\Output\ConsoleOutput))
      /var/www/vendor/laravel/framework/src/Illuminate/Foundation/Console/Kernel.php:131

  32  Illuminate\Foundation\Console\Kernel::handle(Object(Symfony\Component\Console\Input\ArgvInput), Object(Symfony\Component\Console\Output\ConsoleOutput))
      /var/www/artisan:37

```

### 該当のソースコード

```ここに言語名を入力
DB_CONNECTION=mysql
DB_HOST=127.0.0.1
DB_PORT=3306
DB_DATABASE=mybbs
DB_USERNAME=root
DB_PASSWORD=root
```

### 試したこと

エラーを調べながら変更などしましたが、エラーが一向に変わりませんでした。

よろしくお願いします。