我目前正在从事Android类项目。我对数据库中的插入语句有一些麻烦;我正在使用SQLite。当我运行该应用程序时,我的数据库已正确创建,但未插入值。我试图将自己介绍给在线提案和解决方案,并尝试实施它,但无济于事。
请我需要帮助。谢谢。
DBHandler.java
package ck.edu.com.birch;
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 java.text.SimpleDateFormat;
import java.util.Date;
public class DBHandler {
String TAG = "Tennis Tracker";
String DB_NAME = "TennisEFREI.db";
String DB_TABLE = "statistics";
int DB_VERSION = 1;
String SQL_CREATE = "CREATE TABLE " + DB_TABLE +
" (_id INTEGER PRIMARY KEY AUTOINCREMENT, " +
"playerOnename TEXT NOT NULL, " +
"playerTwoname TEXT NOT NULL, " +
"winner TEXT NOT NULL, " +
"wonPointsPlayer1 INTEGER NOT NULL, " +
"wonPointsPlayer2 INTEGER NOT NULL, " +
"wonSetsPlayer1 INTEGER NOT NULL, " +
"wonSetsPlayer2 INTEGER NOT NULL, " +
"acePlayer1 INTEGER, " +
"acePlayer2 INTEGER, " +
"winPlayer1 INTEGER, " +
"winPlayer2 INTEGER, " +
"errorPlayer1 INTEGER, " +
"errorPlayer2 INTEGER, " +
"date TIMESTAMP DEFAULT CURRENT_TIMESTAMP)";
String SQL_DROP = "DROP TABLE IF EXISTS " + DB_TABLE;
DatabaseHelper databaseHelper;
private SQLiteDatabase db;
public DBHandler(Context context) {
databaseHelper = new DatabaseHelper(context);
}
class DatabaseHelper extends SQLiteOpenHelper {
DatabaseHelper(Context context) {
super(context, DB_NAME, null, DB_VERSION);
}
@Override
public void onCreate(SQLiteDatabase db) {
db.execSQL(SQL_CREATE);
}
@Override
public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
db.execSQL(SQL_DROP);
onCreate(db);
}
}
public void open() throws SQLException {
db = databaseHelper.getWritableDatabase();
}
public void close() {
databaseHelper.close();
}
public long insertStatistics(String playerOnename, String playerTwoname, String winner, int wonPointsPlayer1, int wonPointsPlayer2, int wonSetsPlayer1, int wonSetsPlayer2, int acePlayer1, int acePlayer2, int winPlayer1, int winPlayer2, int errorPlayer1, int errorPlayer2) {
SimpleDateFormat simpleDateFormat = new SimpleDateFormat("dd/MM/yyyy");
String date = simpleDateFormat.format(new Date());
ContentValues contentValues = new ContentValues();
contentValues.put("playerOnename", playerOnename);
contentValues.put("playerTwoname", playerTwoname);
contentValues.put("winner", winner);
contentValues.put("wonPointsPlayer1", wonPointsPlayer1);
contentValues.put("wonPointsPlayer2", wonPointsPlayer2);
contentValues.put("wonSetsPlayer1", wonSetsPlayer1);
contentValues.put("wonSetsPlayer2", wonPointsPlayer2);
contentValues.put("acePlayer1", acePlayer1);
contentValues.put("acePlayer2", acePlayer2);
contentValues.put("winPlayer1", winPlayer1);
contentValues.put("winPlayer2", winPlayer2);
contentValues.put("errorPlayer1", errorPlayer1);
contentValues.put("errorPlayer2", errorPlayer2);
contentValues.put("date", date);
Log.d(TAG, "VALUES : " + contentValues);
return db.insert(DB_TABLE, null, contentValues);
}
}
SQLite没有为存储日期和/或时间预留存储类。相反,内置的SQLite Date And Time Functions能够将日期和时间存储为TEXT,REAL或INTEGER值:
- TEXT作为ISO8601字符串(“ YYYY-MM-DD HH:MM:SS.SSS”)。
- REAL作为儒略日数,是公元前4714年11月24日格林威治中午以来的天数。根据多久的公历。
- INTEGER作为Unix时间,自1970-01-01 00:00:00 UTC以来的秒数。
因此,请以这种格式转换日期,然后尝试将表的日期列数据类型插入或设置为文本(我不推荐)。