Android studio sqlite 查询意外错误

Question

在此查询中出现意外错误，我不知道如何解决这个问题，请帮助我。

我运行在 sql 浏览器中这个查询有效，但我不知道如何输入 android 格式方法 select PARTY，从 voter_table 中按 PARTY 分组计数（PARTY）；

public class DatabaseHelper extends SQLiteOpenHelper {
    public static final String DATABASE_NAME = "Vote.db";
    public static final String TABLE_NAME = "voter_table";
    public static final String COL_1 = "ID";
    public static final String COL_2 = "PARTY";
    public static final String COL_3 = "USERNAME";
public int getCountData() {
        SQLiteDatabase db = this.getWritableDatabase();
        Cursor res1 = db.rawQuery("select" +COL_2+", count("+COL_2+") from" +TABLE_NAME+ "group by" +COL_2;);
        res1.moveToFirst();
        int recCount = res1.getInt(0);
        res1.close();
        db.close();
        return recCount;
    }

Answer 1

试试这个

static final String TABLE_NAME = "voter_table";
    public static final String COL_1 = "ID";
    public static final String COL_2 = "PARTY";
    public static final String COL_3 = "USERNAME";
    String query = "SELECT " +COL_2 +",COUNT(" +COL_2 +") FROM " + TABLE_NAME + " GROUP BY " + COL_2 ;

Android studio sqlite 查询意外错误

Android studio sqlite query unexpected error

sqlite

android

android-sqlite

android-studio