我正在尝试在我的 sqlit 数据库中插入数据,但我得到了 android SQLiteConstraintException:错误代码 19:约束失败异常。我看到这个主题有很多问题,我已经阅读并尝试了很多问题,但是仍然存在异常,我想知道这个异常是否是由自动递增 food_id 值引起的,因为插入语句返回 -1 ,并且我想知道为什么自从第一次插入 id 正确完成但后来所有插入都失败后发生此异常,为什么会发生此错误,以及我该如何解决?请帮我..
DBAdapter 类中的创建语句
private static final String Meal_TABLE_CREATE= "create table IF NOT EXISTS Meal (Date text not null , "+
"Time text not null,MealType text not null,"+ " primary key(Date,Time ,MealType) );" ;
private static final String FOOD_TABLE_CREATE= "create table IF NOT EXISTS Food (_id INTEGER primary key AUTOINCREMENT , "+
"Food_Name text not null,Calories integer not null,"+ "VB12 integer not null,Cholesterol integer not null,"+
"Protein integer not null,Iron integer not null,Sodium integer not null,Fat_Mono integer not null,Fat_Sat integer not null,carbohydrate integer not null);" ;
private static final String MealFOOD_TABLE_CREATE= "create table IF NOT EXISTS MealFood (Date text not null , "+
"Time text not null,MealType text not null,"+"Food_ID integer not null , primary key(Date,Time ,MealType,Food_ID) );" ;
插入方法
// insert meal to the meal table
public long SaveMeal(String date , String time , String mealType)
{
ContentValues content = new ContentValues();
content.put(KEY_MDATE,date);
content.put(KEY_MTIME,time);
content.put(KEY_MEALTYPE,mealType);
return db.insert(MEAL_TABLE_NAME, null, content);
}
// insert Food to the Food table
public long SaveFood(String name,int calories,int Vit_B12,int cholesterol,int protein ,int iron ,int sodium,int Fat_Mono,int Fat_Sat,int carbohydrate)
{
ContentValues content = new ContentValues();
content.put(KEY_FOODNAME,name);
content.put(KEY_CALORIES,calories);
content.put(KEY_VB12,Vit_B12);
content.put(KEY_CHOLESTEROL,cholesterol);
content.put(KEY_PROTEIN,protein);
content.put(KEY_IRON,iron);
content.put(KEY_SODIUM,sodium);
content.put(KEY_FAT_MONO,Fat_Mono);
content.put(KEY_FAT_Sat,Fat_Sat);
content.put(KEY_CARBOHYDRATE,carbohydrate);
return db.insert(FOOD_TABLE_NAME, null, content);
}
// get food id by its name
public int getFoodIDByName(String name) throws SQLException
{ int id;
Cursor cursor = null;
try{
cursor=db.query(true,FOOD_TABLE_NAME, new String[]{KEY_FOODID}, KEY_FOODNAME+ " = '" + name + "'", null, null, null, null,null);
if (cursor != null) {
cursor.moveToFirst();
}
id=0;
while (cursor.moveToNext())
id=cursor.getInt(cursor.getColumnIndex(KEY_FOODID));
}
finally{
cursor.close();
cursor.deactivate();
}
return id;
}
// insert mealFood to mealFood table
public long SaveMealFood(String date , String time , String mealType, int Food_id)
{
ContentValues content = new ContentValues();
content.put(KEY_MFDATE,date);
content.put(KEY_MFTIME,time);
content.put(KEY_MFMEALTYPE,mealType);
content.put(KEY_MFFOODID,Food_id);
return db.insert(MEALFOOD_TABLE_NAME, null, content);
}
爪哇代码
DBAdapter dbAdapter=new DBAdapter(SaveMeal.this);
dbAdapter.open();
Food n;
String m;
int FoodIDByName;
for(int i = 0; i <MealActivity.array.size(); i++){
m=MealActivity.array.get(i).toString();
Log.e("tag", m);//selected food name
for (int j = 0; j < MealActivity.tempList.size(); j++){
n=MealActivity.tempList.get(j);
if(n.getFOOD_NAME().equals(m)){
//save food
long food_id = dbAdapter.SaveFood(n.getFOOD_NAME(),n.getCALORIES(),n.getFOOD_VITAMIN_B12(),n.getCHOLESTEROL(),n.getFOOD_PROTEIN(),n.getFOOD_IRON(),n.getFOOD_SODIUM(),
n.getFOOD_MONO_UNSATURATED_FAT(),n.getFOOD_SATURATED_FAT(),n.getFOOD_TOTAL_CARBOHYDRATE());
Log.e("tag", food_id+" food inserting done");
//save meal
long meal_id= dbAdapter.SaveMeal( meal_date,meal_time,Meal.MEAL_TYPE);
Log.e("tag",meal_id+" meal inserting done");
//save meal_food
FoodIDByName=dbAdapter.getFoodIDByName(n.FOOD_NAME);
Log.e("tag",FoodIDByName+" food_id");
long meal_food_id=dbAdapter.SaveMealFood(meal_date,meal_time,Meal.MEAL_TYPE,FoodIDByName);
Log.e("tag",meal_food_id+" meal_food inserting done");
dbAdapter.close();
此行的结果 Log.e("tag", food_id+" food inserting done"); 在我的日志中是-1
我的日志
Database(657):at android.database.sqlite.SQLiteStatement.native_execute(Native Method)
Database(657):at android.database.sqlite.SQLiteStatement.execute (SQLiteStatement.java:55)
Database(657):at android.database.sqlite.SQLiteDatabase.insert(SQLiteDatabase.java:1410)
-1 food inserting done
18 meal inserting done
0 food_id
13 meal_food inserting done