java - Android - 我如何在 SQL 数据库中搜索信息

Question

我想知道如何搜索存储在我的数据库中的特定信息。假设我想搜索存储在 iName 中的信息，我该怎么做？我需要做某种 sql 查询吗？ 很抱歉提出这样一个基本问题，但我对整个 android 场景都是陌生的。谢谢你

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_NAME ="persons_name";
public static final String KEY_HOTNESS ="persons_hotness";

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_ROWID + " INTEGER PRIMARY KEY AUTOINCREMENT, " +
            KEY_NAME + " TEXT NOT NULL, " +
            KEY_HOTNESS + " 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 createEntry(String name, String hotness) {
// TODO Auto-generated method stub
ContentValues cv = new ContentValues();
cv.put(KEY_NAME, name);
cv.put(KEY_HOTNESS, hotness);
return ourDatabase.insert(DATABASE_TABLE, null, cv);

}
public String getData() {
// TODO Auto-generated method stub
String [] columns = new String[]{ KEY_ROWID, KEY_NAME, KEY_HOTNESS};
Cursor c = ourDatabase.query(DATABASE_TABLE, columns, null, null, null, null, null);
String result = "";

int iRow = c.getColumnIndex(KEY_ROWID);
int iName = c.getColumnIndex(KEY_NAME);
int iHotness = c.getColumnIndex(KEY_HOTNESS);

for(c.moveToFirst(); !c.isAfterLast(); c.moveToNext()) {


    result = result + c.getString(iRow) + " "+ c.getString(iName) + " " + c.getString(iHotness) + "\n";
}



return result;
}
}

Answer 1

您需要编写一个类似于您已有的 getData() 的函数，但将名称传递给它...例如:

public Cursor getData(String name) {
    ...
    Cursor c = ourDatabase.query(DATABASE_TABLE, columns, KEY_NAME + "=?", new String[] { name }, null, null, null);
    ...
}