[코틀린을 활용한 안드로이드 프로그래밍] 12장 직접 풀어보기 12-2

[Gradle 설정]

1

id 'kotlin-android-extensions'

cs

<MainActivity>

package com.cookandroid.project12_2
 
import android.content.Context
import android.database.sqlite.SQLiteDatabase
import android.database.sqlite.SQLiteOpenHelper
import androidx.appcompat.app.AppCompatActivity
import android.os.Bundle
import android.widget.Toast
import kotlinx.android.synthetic.main.activity_main.*
 
class MainActivity : AppCompatActivity() {
    lateinit var myHelper : myDBHelper
    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContentView(R.layout.activity_main)
 
        title = "가수 그룹 관리 DB"
        myHelper = myDBHelper(this)
        btnInit.setOnClickListener {
            var sqlDB = myHelper.writableDatabase
            myHelper.onUpgrade(sqlDB, 1, 2)
            sqlDB.close()
        }
 
        btnInsert.setOnClickListener {
            var sqlDB = myHelper.writableDatabase
            sqlDB.execSQL("INSERT INTO groupTBL VALUES('"+ edtName.text.toString() + "' ,"+edtNumber.text.toString() + " ); "  )
            sqlDB.close()
            Toast.makeText(applicationContext, "입력됨", Toast.LENGTH_SHORT).show()
        }
        btnSelect.setOnClickListener {
            var sqlDB = myHelper.readableDatabase
            var cursor = sqlDB.rawQuery("SELECT * FROM groupTBL;", null)
 
            var strNames = "그룹이름" + "\r\n" + "-----" +"\r\n"
            var strNumbers = "인원" + "\r\n" + "-----" +"\r\n"
 
            while(cursor.moveToNext()){
                strNames += cursor.getString(0) + "\r\n"
                strNumbers += cursor.getString(1) + "\r\n"
            }
 
            tvNameResult.text = strNames
            tvNumberResult.text = strNumbers
 
            cursor.close()
            sqlDB.close()
 
        }
 
        btnUpdate.setOnClickListener {
            var sqlDB = myHelper.writableDatabase
            var afterNumber = edtNumber.text.toString().toInt()
            var targetName = edtName.text.toString()
            sqlDB.execSQL("UPDATE groupTBL SET gNumber = '${afterNumber}' WHERE gName = '${targetName}';")
 
            Toast.makeText(applicationContext, "수정됨", Toast.LENGTH_SHORT).show()
            btnSelect.callOnClick()
        }
 
        btnDelete.setOnClickListener {
            var sqlDB = myHelper.writableDatabase
            var targetName = edtName.text.toString()
            sqlDB.execSQL("DELETE FROM groupTBL WHERE gName = '${targetName}';")
            Toast.makeText(applicationContext, "삭제됨", Toast.LENGTH_SHORT).show()
            btnSelect.callOnClick()
        }
 
    }
 
    inner class myDBHelper(context: Context) :SQLiteOpenHelper(context, "groupDB", null, 1){
        override fun onCreate(db: SQLiteDatabase?) {
            db!!.execSQL("CREATE TABLE groupTBL(gName CHAR(20) PRIMARY KEY, gNumber INTEGER)")
        }
 
        override fun onUpgrade(db: SQLiteDatabase?, oldVersion: Int, newVersion: Int) {
            db!!.execSQL("DROP TABLE IF EXISTS groupTBL")
            onCreate(db)
        }
 
    }
}

 

<activity_main.xml>

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical">
 
    <LinearLayout
        android:layout_width="match_parent"
        android:layout_height="0dp"
        android:layout_weight="1"
        android:orientation="horizontal">
        <TextView
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="이름 : "/>
        <EditText
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_weight="1"
            android:id="@+id/edtName"/>
    </LinearLayout>
    <LinearLayout
        android:layout_width="match_parent"
        android:layout_height="0dp"
        android:layout_weight="1"
        android:orientation="horizontal">
        <TextView
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="인원 : "/>
        <EditText
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_weight="1"
            android:id="@+id/edtNumber"/>
    </LinearLayout>
 
    <LinearLayout
        android:layout_width="match_parent"
        android:layout_height="0dp"
        android:layout_weight="1"
        android:orientation="horizontal">
 
        <Button
            android:layout_weight="1"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="초기"
            android:id="@+id/btnInit"/>
        <Button
            android:layout_weight="1"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="입력"
            android:id="@+id/btnInsert"/>
        <Button
            android:layout_weight="1"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="수정"
            android:id="@+id/btnUpdate"/>
        <Button
            android:layout_weight="1"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="삭제"
            android:id="@+id/btnDelete"/>
 
        <Button
            android:layout_weight="1"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="조회"
            android:id="@+id/btnSelect"/>
 
 
    </LinearLayout>
    <LinearLayout
        android:gravity="center"
        android:background="#00FF00"
        android:layout_width="match_parent"
        android:layout_height="0dp"
        android:layout_weight="8"
        android:orientation="horizontal">
        <TextView
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_weight="1"
            android:id="@+id/tvNameResult"/>
        <TextView
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_weight="1"
            android:id="@+id/tvNumberResult"/>
    </LinearLayout>
 
</LinearLayout>