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下面是我得到的錯誤：Android Studio中，SQLite的，沒有這樣的列，發行
java.lang.RuntimeException: Unable to start activity ComponentInfo{groceryproject.jacob.com.recipelist/groceryproject.jacob.com.recipelist.RecipeList}: android.database.sqlite.SQLiteException: no such column: prep_time (code 1): , while compiling: SELECT id, recipe_name, servings, prep_time, cook_time, ingredients, directions FROM recipes WHERE id=?
這是我所卸載的應用程序，並清除所有數據進行確認後，我沒有以前的數據庫搞砸了我。下面是我的數據庫類代碼：
package groceryproject.jacob.com.recipelist;
/**
* Created by Jacob on 11/12/2016.
*/
import java.util.ArrayList;
import java.util.Arrays;
import java.util.List;
import android.content.ContentValues;
import android.content.Context;
import android.database.Cursor;
import android.database.sqlite.SQLiteDatabase;
import android.database.sqlite.SQLiteOpenHelper;
public class RecipeDB extends SQLiteOpenHelper {
// All Static variables
// Database Version
private static final int DATABASE_VERSION = 1;
// Database Name
private static final String DATABASE_NAME = "recipeManager";
// Contacts table name
private static final String TABLE_RECIPES = "recipes";
// Contacts Table Columns names
private static final String KEY_ID = "id";
private static final String KEY_NAME = "recipe_name";
private static final String KEY_COOK_TIME = "cook_time";
private static final String KEY_PREP_TIME = "prep_time";
private static final String KEY_SERVINGS = "servings";
private static final String KEY_INGREDIENTS = "ingredients";
private static final String KEY_DIRECTIONS = "directions";
public RecipeDB(Context context) {
super(context, DATABASE_NAME, null, DATABASE_VERSION);
}
@Override
public void onCreate(SQLiteDatabase db) {
String CREATE_CONTACTS_TABLE = "CREATE TABLE " + TABLE_RECIPES + "("
+ KEY_ID + " INTEGER PRIMARY KEY," + KEY_NAME + " TEXT,"
+ KEY_SERVINGS + " TEXT," + " TEXT," + KEY_COOK_TIME + " TEXT,"
+ KEY_INGREDIENTS + " TEXT," + KEY_DIRECTIONS + " TEXT" + ")";
db.execSQL(CREATE_CONTACTS_TABLE);
}
@Override
public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
// Drop older table if existed
db.execSQL("DROP TABLE IF EXISTS " + TABLE_RECIPES);
// Create tables again
onCreate(db);
}
void addRecipe(Recipe recipe) {
SQLiteDatabase db = this.getWritableDatabase();
ContentValues values = new ContentValues();
values.put(KEY_NAME, recipe.getRecipeName()); // Contact Name
values.put(KEY_SERVINGS, recipe.getServings()); // Contact Phone
values.put(KEY_PREP_TIME, recipe.getPrepTime());
values.put(KEY_COOK_TIME, recipe.getCookTime());
//Next few lines turns an array list of strings into one string seperated by tabs
String directionsConcat = "";
String ingedientsConcat = "";
if(recipe.getIngredients() != null) {
StringBuilder ingred = new StringBuilder();
for (String s : recipe.getIngredients()) {
ingred.append(s);
ingred.append("\t");
}
ingedientsConcat = ingred.toString();
}
if(recipe.getDirections() != null) {
StringBuilder direct = new StringBuilder();
for (String s : recipe.getDirections()) {
direct.append(s);
direct.append("\t");
}
directionsConcat = direct.toString();
}
values.put(KEY_INGREDIENTS, ingedientsConcat);
values.put(KEY_DIRECTIONS, directionsConcat);
db.insert(TABLE_RECIPES, null, values);
db.close(); // Closing database connection
}
Recipe getRecipe(int id) {
SQLiteDatabase db = this.getReadableDatabase();
Cursor cursor = db.query(TABLE_RECIPES, new String[] { KEY_ID,
KEY_NAME, KEY_SERVINGS, KEY_PREP_TIME, KEY_COOK_TIME, KEY_INGREDIENTS, KEY_DIRECTIONS },
KEY_ID + "=?", new String[] { String.valueOf(id) }, null, null, null, null); //This line is where the error points to
if (cursor != null)
cursor.moveToFirst();
List<String> directionsList = new ArrayList<>();
List<String> ingredientsList = new ArrayList<>();
String ingredients = cursor.getString(5);
String directions = cursor.getString(6);
if (directions != null){
if(directions.contains("\t")) {
directionsList = Arrays.asList(directions.split("\t"));
}
else{
directionsList = Arrays.asList(directions);
}
}
if (ingredients != null){
if(ingredients.contains("\t")) {
ingredientsList = Arrays.asList(ingredients.split("\t"));
}
else{
ingredientsList = Arrays.asList(ingredients);
}
}
Recipe recipe = new Recipe(Integer.parseInt(cursor.getString(0)), cursor.getString(1), cursor.getString(2),
cursor.getString(3), cursor.getString(4), ingredientsList, directionsList);
return recipe;
}
public List<Recipe> getAllRecipes() {
List<Recipe> recipeList = new ArrayList<Recipe>();
String selectQuery = "SELECT * FROM " + TABLE_RECIPES;
SQLiteDatabase db = this.getWritableDatabase();
Cursor cursor = db.rawQuery(selectQuery, null);
if (cursor.moveToFirst()) {
do {
Recipe recipe = new Recipe();
recipe.setID(Integer.parseInt(cursor.getString(0)));
recipe.setRecipeName(cursor.getString(1));
recipe.setServingSize(cursor.getString(2));
recipe.setPrepTime(cursor.getString(3));
recipe.setCookTime(cursor.getString(4));
List<String> directionsList = new ArrayList<>();
List<String> ingredientsList = new ArrayList<>();
String ingredients = cursor.getString(5);
String directions = cursor.getString(6);
if (directions != null){
if(directions.contains("\t")) {
directionsList = Arrays.asList(directions.split("\t"));
}
else{
directionsList = Arrays.asList(directions);
}
}
if (ingredients != null){
if(ingredients.contains("\t")) {
ingredientsList = Arrays.asList(ingredients.split("\t"));
}
else{
ingredientsList = Arrays.asList(ingredients);
}
}
recipe.setIngredients(ingredientsList);
recipe.setDirections(directionsList);
recipeList.add(recipe);
} while (cursor.moveToNext());
}
return recipeList;
}
public int updateRecipe(Recipe recipe) {
SQLiteDatabase db = this.getWritableDatabase();
ContentValues values = new ContentValues();
values.put(KEY_NAME, recipe.getRecipeName()); // Contact Name
values.put(KEY_SERVINGS, recipe.getServings()); // Contact Phone
values.put(KEY_PREP_TIME, recipe.getPrepTime());
values.put(KEY_COOK_TIME, recipe.getCookTime());
//Next few lines turns an array list of strings into one string seperated by tabs
String directionsConcat = "";
String ingedientsConcat = "";
if(recipe.getIngredients() != null) {
StringBuilder ingred = new StringBuilder();
for (String s : recipe.getIngredients()) {
ingred.append(s);
ingred.append("\t");
}
ingedientsConcat = ingred.toString();
}
if(recipe.getDirections() != null) {
StringBuilder direct = new StringBuilder();
for (String s : recipe.getDirections()) {
direct.append(s);
direct.append("\t");
}
directionsConcat = direct.toString();
}
values.put(KEY_INGREDIENTS, ingedientsConcat);
values.put(KEY_DIRECTIONS, directionsConcat);
// updating row
return db.update(TABLE_RECIPES, values, KEY_ID + " = ?",
new String[] { String.valueOf(recipe.getID()) });
}
public void deleteRecipe(Recipe recipe) {
SQLiteDatabase db = this.getWritableDatabase();
db.delete(TABLE_RECIPES, KEY_ID + " = ?",
new String[] { String.valueOf(recipe.getID()) });
db.close();
}
public int getRecipeCount() {
String countQuery = "SELECT * FROM " + TABLE_RECIPES;
SQLiteDatabase db = this.getReadableDatabase();
Cursor cursor = db.rawQuery(countQuery, null);
cursor.close();
// return count
return cursor.getCount();
}
}
當我打電話getRecipe()從我的主Activity類的問題造成的：
package groceryproject.jacob.com.recipelist;
import android.app.Activity;
import android.content.ContentValues;
import android.content.Context;
import android.content.Intent;
import android.database.sqlite.SQLiteDatabase;
import android.os.Parcelable;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.support.v7.widget.LinearLayoutManager;
import android.support.v7.widget.RecyclerView;
import android.util.Log;
import android.view.View;
import android.widget.Button;
import java.util.ArrayList;
import java.util.List;
public class RecipeList extends AppCompatActivity{
private RecyclerView mRecyclerView;
private RecyclerView.Adapter mAdapter;
private RecyclerView.LayoutManager mLayoutManager;
private int REQUEST_CODE=1;
//private SQLiteDatabase mDatabase;
//TODO: Create a new taskbar
//TODO: Create a navigaton bar.
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
RecipeDB dbHelper = new RecipeDB(this);
/*
if(savedInstanceState != null){
recipes = savedInstanceState.getParcelableArrayList("savedRecipes");
}
*/
ArrayList<String> one = new ArrayList<>();
one.add("Test");
Recipe testRecipe = new Recipe("Name", "Four slices", "40", "80", one, one);
dbHelper.addRecipe(testRecipe);
Recipe testTwo = dbHelper.getRecipe(1); //This is where it breaks
List<Recipe> recipes = dbHelper.getAllRecipes();
recipes.add(testTwo); //This is to prove the adapter is working
String log = "No results";
for (Recipe rn : recipes){
log = "Id: " + rn.getID() + ", Name: " + rn.getRecipeName();
}
Log.d("Name, ", log);
//This log is printing no results when the app actually runs
setContentView(R.layout.activity_recipe_list);
mRecyclerView = (RecyclerView) findViewById(R.id.list_recycler_view);
mLayoutManager = new LinearLayoutManager(this);
mRecyclerView.setLayoutManager(mLayoutManager);
mAdapter = new MyAdapter(recipes);
mRecyclerView.setAdapter(mAdapter);
}
在getRecipe()光標線是在錯誤日誌指向。它只發生在我打電話給getRecipe()時。如果我要創建一個名爲getAllRecipes()的列表，並將其傳遞給適配器，它在啓動時不會崩潰，但ArrayList也是空的。
我知道適配器的工作原理，因爲如果我手動將它添加到數組列表食譜，它會正確顯示在屏幕上。這是造成這個問題的數據庫。
我一直在這個工作了幾天，並試圖在許多類似的問題上看到，所以我只是覺得卡住了。任何建議表示讚賞。
謝謝，我覺得有點傻。是的，聯繫人是一個陌生的名字。由於這是我第一次使用SQL，我一直在關注一個教程。我完全依據指南第一次創建了這個類，但無法使其工作。所以我在經過幾天的失敗之後複製並翻譯了（錯過了這個）。我只是沒有意識到我的答案如此接近......再次感謝你！ – knokout1
有一堆庫讓SQLite變得更容易。例如，RealmDB是一個很受歡迎的程序。 SugarORM也是如此 –