Android SQLite rawQuery()方法
我创建了一个表,其中有三列Android SQLite rawQuery()方法,android,sqlite,android-sqlite,Android,Sqlite,Android Sqlite,我创建了一个表,其中有三列id、name和规程。 我想查找给定学科的学生姓名 以下是我的方法: String findstudent(String disc){ SQLiteDatabase sqLiteDatabase = this.getReadableDatabase(); String find = "SELECT * FROM "+ TABLE_STUDENTS + " WHERE "+KEY_DISCIPLINE +" = " +disc ; Cursor
id
、name
和规程
。
我想查找给定学科的学生姓名
以下是我的方法:
String findstudent(String disc){
SQLiteDatabase sqLiteDatabase = this.getReadableDatabase();
String find = "SELECT * FROM "+ TABLE_STUDENTS + " WHERE "+KEY_DISCIPLINE +" = " +disc ;
Cursor cursor = sqLiteDatabase.rawQuery(find,null);
cursor.moveToFirst();
String found =cursor.getString(1);
return found;
}
当我使用它时,应用程序停止工作。尝试以下操作:
String findstudent(String disc){
Cursor cursor;
cursor = this.db.query(TABLE_STUDENTS,null, KEY_DISCIPLINE +" = "+ disc, null, null, null, null,null );
cursor.moveToFirst();
String found =cursor.getString(0);
return found;
}
希望能有帮助
public Cursor findstudent(String disc){
SQLiteDatabase sqLiteDatabase = this.getReadableDatabase();
String[] find = new String[]{ col1,col2,col3};//all fields in db in need
String order=col1;
Cursor c=db.query(TABLE_STUDENTS, find, KEY_DISCIPLINE +" = " +disc, null, null, null, order);
c.moveToFirst();
db.close();
return c;
}
活动中包括以下内容:
DataBaseHandler db = new DataBaseHandler(this);
try {
Cursor c = db.displayName(your_disc);
startManagingCursor(c);
if (!c.moveToFirst()) {
System.out.println("!Move " + posnumber);
} else {
String idname = c.getString(c
.getColumnIndex(DataBaseHandler.KEY_NAME));
System.out.println("null:");
System.out.println("Move " + idname);
return true;
}
c.close();
stopManagingCursor(c);
} catch (Exception ex) {
}
我不确定。但是,你可以这样尝试
Cursor.moveToFirst();
do{
//get the data
String found =cursor.getString(cursor.getColumnIndexOrThrow("COLUMN NAME"));
}while(Cursor.moveNext);
请尝试以下代码:
String find = "SELECT *<enter code here>
FROM "+ TABLE_STUDENTS + "
WHERE "+KEY_DISCIPLINE +" = '" + disc + "'" ;
String find=“选择*
来自“+表_学生+”
式中“+钥匙+纪律+”=“+disc+”;
如果您的应用程序停止工作,请检查并在此处发布Logcat输出。首先,请在使用完cursor.close()后调用它。thnx,仍然不工作。。