也许这个问题是重复的，但我找不到与我的代码类似的答案。
我想在插入之前检查数据库值。
如果存在值，我想跳过并继续下一次插入。
这是我的插入
public void insertPlayer1Songlist() {
createPlayer1("Song Title 1", "Artist 1", "Vol 1","","0","12341");
createPlayer1("Song Title 2", "Artist 2", "Vol 2","","0","12342");
createPlayer1("Song Title 3", "Artist 3", "Vol 3","","0","12343");
createPlayer1("Song Title 4", "Artist 4", "Vol 4","","0","12344");
createPlayer1("Song Title 5", "Artist 5", "Vol 5","","0","12345");
createPlayer1("Song Title 6", "Artist 6", "Vol 6","","0","12346");
createPlayer1("Song Title 7", "Artist 7", "Vol 7","","0","12347");
createPlayer1("Song Title 8", "Artist 8", "Vol 8","","0","12348");
createPlayer1("Song Title 9", "Artist 9", "Vol 9","","0","12349");
createPlayer1("Song Title 10", "Artist 10", "Vol 10","","0","12310");
createPlayer1("Song Title 11", "Artist 11", "Vol 11","","0","12311");
createPlayer1("Song Title 12", "Artist 12", "Vol 12","","0","12312");
}
这里是我想检查数据库中是否已有值的地方..
public long createPlayer1(String title,
String artist, String volume,
String type, String favorite, String number) {
ContentValues initialValues = new ContentValues();
initialValues.put(KEY_TITLE, title);
initialValues.put(KEY_ARTIST, artist);
initialValues.put(KEY_VOLUME, volume);
initialValues.put(KEY_TYPE, type);
initialValues.put(KEY_FAVORITE, favorite);
initialValues.put(KEY_NUMBER, number);
return mDb.insert(SQLITE_TABLE, null, initialValues);
}
我想检查数字是否已存入数据库。
如果是，我想跳过并继续使用此代码。
return mDb.insert(SQLITE_TABLE, null, initialValues);
完整代码..
package com.magicstarme.virtualsongbook;
import android.content.ContentValues;
import android.content.Context;
import android.database.Cursor;
import android.database.SQLException;
import android.database.sqlite.SQLiteDatabase;
import android.database.sqlite.SQLiteOpenHelper;
import android.util.Log;
import android.widget.Toast;
/**
* Created by Joe on 7/7/2016.
*/
public class FragmentOne_DbAdapter {
public static final String KEY_ROWID = "_id";
public static final String KEY_TITLE = "title";
public static final String KEY_ARTIST = "artist";
public static final String KEY_VOLUME = "volume";
public static final String KEY_TYPE = "type";
public static final String KEY_FAVORITE = "favorite";
public static final String KEY_NUMBER = "number";
private static final String TAG = "FragmentOne_DbAdapter";
private DatabaseHelper mDbHelper;
private SQLiteDatabase mDb;
private static final String DATABASE_NAME = "Virtualsongbook";
private static final String SQLITE_TABLE = "Player1";
private static final int DATABASE_VERSION = 1;
private final Context mCtx;
private static final String DATABASE_CREATE =
"CREATE TABLE if not exists " + SQLITE_TABLE + " (" +
KEY_ROWID + " integer PRIMARY KEY autoincrement," +
KEY_TITLE + "," +
KEY_ARTIST + "," +
KEY_VOLUME + "," +
KEY_TYPE + "," +
KEY_FAVORITE + "," +
KEY_NUMBER + ")";
private static class DatabaseHelper extends SQLiteOpenHelper {
DatabaseHelper(Context context) {
super(context, DATABASE_NAME, null, DATABASE_VERSION);
}
@Override
public void onCreate(SQLiteDatabase db) {
Log.w(TAG, DATABASE_CREATE);
db.execSQL(DATABASE_CREATE);
}
@Override
public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
Log.w(TAG, "Upgrading database from version " + oldVersion + " to "
+ newVersion + ", which will destroy all old data");
db.execSQL("DROP TABLE IF EXISTS " + SQLITE_TABLE);
onCreate(db);
}
}
public FragmentOne_DbAdapter(Context ctx) {
this.mCtx = ctx;
}
public FragmentOne_DbAdapter open() throws SQLException {
mDbHelper = new DatabaseHelper(mCtx);
mDb = mDbHelper.getWritableDatabase();
return this;
}
public void close() {
if (mDbHelper != null) {
mDbHelper.close();
}
}
private boolean isRecordExistInDatabase(String tableName, String field, String value) {
Cursor c = mDb.rawQuery("SELECT * FROM " + tableName + " WHERE " + field + "=" + value, null);
if (c.moveToFirst()) {
//Record exist
c.close();
return true;
}
//Record available
c.close();
return false;
}
public long createPlayer1(String title,
String artist, String volume,
String type, String favorite, String number) {
if(isRecordExistInDatabase(SQLITE_TABLE, KEY_NUMBER, number)){
return 0;
}
ContentValues initialValues = new ContentValues();
initialValues.put(KEY_TITLE, title);
initialValues.put(KEY_ARTIST, artist);
initialValues.put(KEY_VOLUME, volume);
initialValues.put(KEY_TYPE, type);
initialValues.put(KEY_FAVORITE, favorite);
initialValues.put(KEY_NUMBER, number);
return mDb.insert(SQLITE_TABLE, null, initialValues);
}
public boolean deleteAllPlayer1() {
int doneDelete = 0;
doneDelete = mDb.delete(SQLITE_TABLE, null , null);
Log.w(TAG, Integer.toString(doneDelete));
return doneDelete > 0;
}
public Cursor fetchPlayer1ByTitle(String titleText) throws SQLException {
Log.w(TAG, titleText);
Cursor mCursor = null;
if (titleText == null || titleText.length () == 0) {
mCursor = mDb.query(SQLITE_TABLE, new String[] {KEY_ROWID,
KEY_TITLE, KEY_ARTIST, KEY_VOLUME, KEY_TYPE, KEY_FAVORITE, KEY_NUMBER},
null, null, null, null, null);
}
else {
mCursor = mDb.query(true, SQLITE_TABLE, new String[] {KEY_ROWID,
KEY_TITLE, KEY_ARTIST, KEY_VOLUME, KEY_TYPE, KEY_FAVORITE, KEY_NUMBER},
KEY_TITLE + " like '%" + titleText + "%'", null,
null, null, null, null);
}
if (mCursor != null) {
mCursor.moveToFirst();
}
return mCursor;
}
public Cursor fetchAllPlayer1() {
Cursor mCursor = mDb.query(SQLITE_TABLE, new String[] {KEY_ROWID,
KEY_TITLE, KEY_ARTIST, KEY_VOLUME, KEY_TYPE, KEY_FAVORITE, KEY_NUMBER},
null, null, null, null, null);
if (mCursor != null) {
mCursor.moveToFirst();
}
return mCursor;
}
public boolean updateItemFavorite(long rowId, String favorite) {
int doneUpdate = 0;
ContentValues values = new ContentValues();
values.put(KEY_FAVORITE, favorite);
//doneUpdate = mDb.update(SQLITE_TABLE, values, KEY_ROWID + " = ?", new String[] { String.valueOf(rowId) });
doneUpdate = mDb.update(SQLITE_TABLE, values, KEY_ROWID + "=" + rowId,null);
Log.w(TAG, Integer.toString(doneUpdate));
return doneUpdate > 0;
//return mDb.update(SQLITE_TABLE, values, KEY_ROWID+"="+rowId,null);
}
public void insertPlayer1Songlist() {
//TYPE
//0 - NONE
//1 - NEW
createPlayer1("Song Title 1", "Artist 1", "Vol 1","0","0","12341");
createPlayer1("Song Title 2", "Artist 2", "Vol 2","0","0","12342");
createPlayer1("Song Title 3", "Artist 3", "Vol 3","0","0","12343");
createPlayer1("Song Title 4", "Artist 4", "Vol 4","0","0","12344");
createPlayer1("Song Title 5", "Artist 5", "Vol 5","0","0","12345");
createPlayer1("Song Title 6", "Artist 6", "Vol 6","0","0","12346");
createPlayer1("Song Title 7", "Artist 7", "Vol 7","0","0","12347");
createPlayer1("Song Title 8", "Artist 8", "Vol 8","0","0","12348");
createPlayer1("Song Title 9", "Artist 9", "Vol 9","0","0","12349");
createPlayer1("Song Title 10", "Artist 10", "Vol 10","0","0","12310");
createPlayer1("Song Title 11", "Artist 11", "Vol 11","0","0","12311");
createPlayer1("Song Title 12", "Artist 12", "Vol 12","0","0","12312");
/*createPlayer1("Song Title 1", "Artist 1", "Vol 1","0","0","12341");
createPlayer1("Song Title 1", "Artist 1", "Vol 1","0","0","12341");
createPlayer1("Song Title 1", "Artist 1", "Vol 1","0","0","12341");
createPlayer1("Song Title 1", "Artist 1", "Vol 1","0","0","12341");
createPlayer1("Song Title 2", "Artist 2", "Vol 2","0","0","12342");
createPlayer1("Song Title 2", "Artist 2", "Vol 2","0","0","12342");
createPlayer1("Song Title 2", "Artist 2", "Vol 2","0","0","12342");
createPlayer1("Song Title 2", "Artist 2", "Vol 2","0","0","12342");
createPlayer1("Song Title 2", "Artist 2", "Vol 2","0","0","12342");
createPlayer1("Song Title 12", "Artist 12", "Vol 12","0","0","12312");
createPlayer1("Song Title 12", "Artist 12", "Vol 12","0","0","12312");
createPlayer1("Song Title 12", "Artist 12", "Vol 12","0","0","12312");
createPlayer1("Song Title 12", "Artist 12", "Vol 12","0","0","10000");*/
}
}
请帮助我，
感谢。
答案 0 :(得分：1)
Y答案 1 :(得分：0)
public boolean rowIdExists(String StrId) {
SQLiteDatabase db = this.getWritableDatabase();
Cursor cursor = db.rawQuery("select id from " + TABLE_USER
+ " where id=?", new String[]{StrId});
boolean exists = (cursor.getCount() > 0);
return exists;
}
public void insertuserrate(String Str[], Context cxt) {
// TODO Auto-generated method stub
String strId = "";
try {
SQLiteDatabase db = this.getWritableDatabase();
ContentValues values = new ContentValues();
{
values.put(KEY_RID, Str[0]);
values.put(ALL_name, Str[1]);
if (rowIdExists(Str[0])) {
db.update(TABLE_USER, values, "id " + "=" + Str[0], null);
} else {
db.insert(TABLE_USER, null, values);
}
//database connection
}
try {
db.close();
} catch (Exception e) {
e.printStackTrace();
}
} catch (Exception e) {
e.printStackTrace();
}
}
答案 2 :(得分：0)
您可以检查数据库中是否存在数字，如下所示：
public long createPlayer1(String title,
String artist, String volume,
String type, String favorite, String number) {
String query = "SELECT * FROM " + SQLITE_TABLE;
Cursor cursor = mDb.rawQuery(query, null);
int ColumeNumber = cursor.getColumnIndex("Number"); // your column title in the table
while (cursor.moveToNext()) {
String num = cursor.getString(ColumeNumber);
if(num.equals(number)) return -1; // has existed, so not insert and return now
}
cursor.close();
ContentValues initialValues = new ContentValues();
initialValues.put(KEY_TITLE, title);
initialValues.put(KEY_ARTIST, artist);
initialValues.put(KEY_VOLUME, volume);
initialValues.put(KEY_TYPE, type);
initialValues.put(KEY_FAVORITE, favorite);
initialValues.put(KEY_NUMBER, number);
return mDb.insert(SQLITE_TABLE, null, initialValues);
}