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android - 我无法使用房间结果从 Sqlite 获取数据结果为 0

问题描述

我有一个使用房间的应用程序。我试图用这个从数据库中获取数据，但结果为 0。我在 db 中有一条记录。我正在调试，但我看不到错误。我还应该控制什么？

//实体类 Apartment.class

@Entity(tableName = "Apartment")
public class Apartment {
@PrimaryKey(autoGenerate = true)
private int id;
@ColumnInfo(name = "barcode")
private String barcode;
@ColumnInfo(name = "image", typeAffinity = ColumnInfo.BLOB)
private byte[] image;
@ColumnInfo(name = "information")
private String information;

public int getId() {
    return id;
}

public void setId(int id) {
    this.id = id;
}

public String getBarcode() {
    return barcode;
}

public void setBarcode(String barcode) {
    this.barcode = barcode;
}

public byte[] getImage() {
    return image;
}

public void setImage(byte[] image) {
    this.image = image;
}

public String getInformation() {
    return information;
}

public void setInformation(String information) {
    this.information = information;
}

道类的样子

ApartmentDao


@Dao
public interface ApartmentDAO {
String barcodeno=variable.barcode;
@Query("SELECT * FROM Apartment WHERE barcode LIKE '%' ||8681715340340||'%'")
List<Apartment> getwithbarcode();

AppDatabase 类看起来像：

AppDatabase.class

 @Database(entities = {Apartment.class}, version = 1)
 public abstract class AppDatabase extends RoomDatabase {
 public abstract ApartmentDAO apartmentDAO();

 }


 I called here look like
 MyActivity.class


 AppDatabase db=Room.databaseBuilder(getApplicationContext(), AppDatabase.class, "RealEstateDb")
           .allowMainThreadQueries()
           .build();

  List<Apartment> apartment=db.apartmentDAO().getwithbarcode();

我究竟做错了什么？您的帮助将不胜感激。

标签： androidandroid-sqliteandroid-roomandroidx

解决方案

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