Java android.database.sqlite.SQLiteConstraintException:唯一约束失败无法理解错误说明
我在Android Studio中遇到了上面提到的错误消息。我的数据库很简单 第1列:名称文本主键 第二栏:价格文本 我已经在StackOverflow中查看了相同问题的答案,但无法解决错误 我在这里引用我的DataBaseHelper类和insertActivity:Java android.database.sqlite.SQLiteConstraintException:唯一约束失败无法理解错误说明,java,android,sqlite,android-sqlite,Java,Android,Sqlite,Android Sqlite,我在Android Studio中遇到了上面提到的错误消息。我的数据库很简单 第1列:名称文本主键 第二栏:价格文本 我已经在StackOverflow中查看了相同问题的答案,但无法解决错误 我在这里引用我的DataBaseHelper类和insertActivity: private static final String DATABASE_NAME = "ItemDatabase"; private static final int DATABASE_V
private static final String DATABASE_NAME = "ItemDatabase";
private static final int DATABASE_VERSION = 1;
private static final String TABLE_NAME = "Items";
private static final String COLUMN_NAME = "Name";
private static final String COLUMN_PRICE = "Price";
DataBaseHelper(Context context)
{
super(context, DATABASE_NAME, null, DATABASE_VERSION);
}
@Override
public void onCreate(SQLiteDatabase sqLiteDatabase) {
sqLiteDatabase.execSQL("CREATE TABLE IF NOT EXISTS "+ TABLE_NAME + "(" + COLUMN_NAME + " TEXT NOT NULL PRIMARY KEY, " + COLUMN_PRICE + " TEXT);");
}
@Override
public void onUpgrade(SQLiteDatabase sqLiteDatabase, int i, int i1) {
String sql = "DROP TABLE IF EXISTS " + TABLE_NAME + ";";
sqLiteDatabase.execSQL(sql);
onCreate(sqLiteDatabase);
}
boolean addItem(String itemName, String itemPrice) {
ContentValues contentValues = new ContentValues();
contentValues.put(COLUMN_NAME, itemName);
contentValues.put(COLUMN_PRICE, itemPrice);
SQLiteDatabase db = this.getWritableDatabase();
boolean b = db.insert(TABLE_NAME, null, contentValues) != -1;
db.close();
return b;
}
Cursor getPrice(String itemName) {
SQLiteDatabase db = this.getReadableDatabase();
return db.rawQuery(" SELECT Price FROM Items WHERE Name= ? ", new String[]{itemName});
}
Cursor updatePrice(String itemName, String itemPrice)
{
SQLiteDatabase db = this.getReadableDatabase();
return db.rawQuery(" UPDATE Items SET Price= ? WHERE Name= ? ", new String[]{itemPrice,itemName});
}
public List<String> getName(){
List<String> list = new ArrayList<String>();
String selectQuery = "SELECT * FROM " + TABLE_NAME;
SQLiteDatabase db = this.getReadableDatabase();
Cursor cursor = db.rawQuery(selectQuery, null);
if (cursor.moveToFirst()) {
do {
list.add(cursor.getString(0));
} while (cursor.moveToNext());
}
cursor.close();
db.close();
return list;
}
}
错误:
W/System.err: at android.database.sqlite.SQLiteConnection.nativeExecuteForChangedRowCount(Native Method)
at android.database.sqlite.SQLiteConnection.executeForChangedRowCount(SQLiteConnection.java:746)
W/System.err: at android.database.sqlite.SQLiteSession.executeForChangedRowCount(SQLiteSession.java:754)
at android.database.sqlite.SQLiteStatement.executeUpdateDelete(SQLiteStatement.java:64)
at android.database.sqlite.SQLiteDatabase.executeSql(SQLiteDatabase.java:1770)
at android.database.sqlite.SQLiteDatabase.execSQL(SQLiteDatabase.java:1698)
at com.anirbit.anirbitadak.nirman.DataBaseHelper.addItem(DataBaseHelper.java:45)
W/System.err: at com.anirbit.anirbitadak.nirman.insertActivity$1.onClick(insertActivity.java:39)
at android.view.View.performClick(View.java:6597)
at android.view.View.performClickInternal(View.java:6574)
at android.view.View.access$3100(View.java:778)
at android.view.View$PerformClick.run(View.java:25881)
W/System.err: at android.os.Handler.handleCallback(Handler.java:873)
at android.os.Handler.dispatchMessage(Handler.java:99)
W/System.err: at android.os.Looper.loop(Looper.java:164)
at android.app.ActivityThread.main(ActivityThread.java:6649)
at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:493)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:826)```
这些线路:
final String Name=itemName.getText().toString();
final String Price=itemPrice.getText().toString();
将EditText
sitemName
和itemPrice
的文本分配给变量Name
和itemPrice
,当insertActivity
加载时(可能它们只是空字符串),并且永远不会更改它们。因此,当您单击按钮时,侦听器会调用
dataBaseHelper.addItem(Name,Price)
尝试在表中插入相同的值,这会导致出现错误,因为列Name
是表的主键,所以它必须是唯一的。
您必须做的是在侦听器中移动这些行:
buttonInsert.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
final String Name=itemName.getText().toString();
final String Price=itemPrice.getText().toString();
try {
................................................
}
因此,当您单击按钮时,将从编辑文本中检索正确的值,然后将其插入表中。这些行:
final String Name=itemName.getText().toString();
final String Price=itemPrice.getText().toString();
将EditText
sitemName
和itemPrice
的文本分配给变量Name
和itemPrice
,当insertActivity
加载时(可能它们只是空字符串),并且永远不会更改它们。
因此,当您单击按钮时,侦听器会调用dataBaseHelper.addItem(Name,Price)
尝试在表中插入相同的值,这会导致出现错误,因为列Name
是表的主键,所以它必须是唯一的。
您必须做的是在侦听器中移动这些行:
buttonInsert.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
final String Name=itemName.getText().toString();
final String Price=itemPrice.getText().toString();
try {
................................................
}
因此,当您单击按钮时,将从EditText
s中检索正确的值,然后将其插入表中