假设我想比较 sqlite 数据库中的变量,如果屏幕上显示的文本与其相同,则在屏幕上打印错误。我尝试了 if (info.getData == info.getData ) then print error
但这不起作用,如果有人知道如何做,请告诉我
TextView tv = (TextView) findViewById(R.id.tvSQLinfo);
HotOrNot info = new HotOrNot(this);
info.open();
String data = info.getData();
info.close();
tv.setText(data);
if(info.getData().equals(info.getData())){
tv.setText("hey");
// this prints error
}
代码:
package f.s.l;
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.SQLiteDatabase.CursorFactory;
import android.database.sqlite.SQLiteOpenHelper;
public class HotOrNot {
public static final String KEY_ROWID ="_id";
public static final String KEY_DAY ="persons_day";
private static final String DATABASE_NAME ="HotOrNotdb";
private static final String DATABASE_TABLE ="peopleTable";
private static final int DATABASE_VERSION =1;
private DbHelper ourHelper;
private final Context ourContext;
private SQLiteDatabase ourDatabase;
private static class DbHelper extends SQLiteOpenHelper{
public DbHelper(Context context) {
super(context, DATABASE_NAME, null, DATABASE_VERSION);
// TODO Auto-generated constructor stub
}
@Override
public void onCreate(SQLiteDatabase db) {
// TODO Auto-generated method stub
db.execSQL("CREATE TABLE " + DATABASE_TABLE + " (" +
KEY_DAY + " TEXT NOT NULL);"
);
}
@Override
public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
// TODO Auto-generated method stub
db.execSQL("DROP TABLE IF EXISTS " + DATABASE_TABLE);
onCreate(db);
}
}
public HotOrNot(Context c){
ourContext =c;
}
public HotOrNot open() throws SQLException{
ourHelper = new DbHelper(ourContext);
ourDatabase = ourHelper.getWritableDatabase();
return this;
}
public void close(){
ourHelper.close();
}
public long createEntry1(String day) {
// TODO Auto-generated method stub
ContentValues cv = new ContentValues();
cv.put(KEY_DAY, day);
return ourDatabase.insert(DATABASE_TABLE, null, cv);
}
public String getData() {
// TODO Auto-generated method stub
String [] columns = new String[]{KEY_DAY};
Cursor c = ourDatabase.query(DATABASE_TABLE, columns, null, null, null, null, null);
String result = "";
int iDay = c.getColumnIndex(KEY_DAY);
for(c.moveToFirst(); !c.isAfterLast(); c.moveToNext()) {
result = result +c.getString(iDay) +"\n";
}
return result;
}
}
最佳答案
在Java中,如果要比较字符串,则需要使用equals
方法。对于你的情况,像这样:
if (info.getData().equals(info.getData()) {
// do something
}
同样,如果你不关心大小写,你可以这样做:
if (info.getData().equalsIgnoreCase(info.getData()) {
// do something
}
关于android - 比较 SQLite 中的变量,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/9855801/