如何在android工作室的不同活动中将数据插入sqlite的单行数据库中

Question

我做了一个帮手 class 名字叫baby

public class Baby {
    private int baby_id;
    private String baby_name;
    private String birthdate;
    private String gender;
    private String age;
    private String height;
    private String weight;
    private String sleep;
    private String medicate;


    public int getBaby_id() {
        return baby_id;
    }

    public void setBaby_id(int baby_id) {
        this.baby_id = baby_id;
    }

    public String getBaby_name() {
        return baby_name;
    }

    public void setBaby_name(String baby_name) {
        this.baby_name = baby_name;
    }

    public String getBirthdate() {
        return birthdate;
    }

    public void setBirthdate(String birthdate) {
        this.birthdate = birthdate;
    }

    public String getGender() {
        return gender;
    }

    public void setGender(String gender) {
        this.gender = gender;
    }

    public String getAge() {
        return age;
    }

    public void setAge(String age) {
        this.age = age;
    }

    public String getHeight() {
        return height;
    }

    public void setHeight(String height) {
        this.height = height;
    }

    public String getWeight() {
        return weight;
    }

    public void setWeight(String weight) {
        this.weight = weight;
    }

    public String getSleep() {
        return sleep;
    }

    public void setSleep(String sleep) {
        this.sleep = sleep;
    }

    public String getMedicate() {
        return medicate;
    }

    public void setMedicate(String medicate) {
        this.medicate = medicate;
    }
}

和数据库活动

private static final int DATABASE_VERSION = 10;
private static final String DATABASE_NAME = "BabyDetails.db";
private static final String TABLE_BABY = "baby";
private static final String COLUMN_BABY_ID = "baby_id";
private static final String COLUMN_BABY_NAME = "baby_name";
private static final String COLUMN_BABY_DATE = "birthdate";
private static final String COLUMN_BABY_GENDER = "gender";
private static final String COLUMN_BABY_AGE = "Age_group";
private static final String COLUMN_BABY_HEIGHT = "height";
private static final String COLUMN_BABY_WEIGHT = "weight";
private static final String COLUMN_BABY_SLEEP = "sleep";
private static final String COLUMN_BABY_MEDICATE = "medicate";


private String CREATE_BABY_TABLE = "CREATE TABLE "+ TABLE_BABY + "(" +
    COLUMN_BABY_ID + " INTEGER  PRIMARY KEY AUTOINCREMENT , " + COLUMN_BABY_NAME + " TEXT, "
    + COLUMN_BABY_DATE + " TEXT, " + COLUMN_BABY_GENDER + " TEXT, " + COLUMN_BABY_AGE + " TEXT, "
    +COLUMN_BABY_HEIGHT+ " TEXT, " + COLUMN_BABY_WEIGHT + " TEXT, " +COLUMN_BABY_SLEEP+ " TEXT, "
    +COLUMN_BABY_MEDICATE+ " TEXT " + ")";


private String DROP_BABY_TABLE = "DROP TABLE IF EXISTS " + TABLE_BABY;

public DbaseBaby( Context context) {
    super(context,DATABASE_NAME,null,DATABASE_VERSION);
}

@Override
public void onCreate(SQLiteDatabase db) {

    db.execSQL(CREATE_BABY_TABLE);
}

@Override
public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {

    db.execSQL(DROP_BABY_TABLE);
    onCreate(db);
}


public void addBaby(@NonNull Baby baby){
    SQLiteDatabase db= this.getWritableDatabase();
    ContentValues values = new ContentValues();
    values.put(COLUMN_BABY_NAME,baby.getBaby_name());
    values.put(COLUMN_BABY_DATE,baby.getBirthdate());
    values.put(COLUMN_BABY_GENDER,baby.getGender());
    values.put(COLUMN_BABY_AGE,baby.getAge());
    values.put(COLUMN_BABY_HEIGHT,baby.getHeight());
    values.put(COLUMN_BABY_WEIGHT,baby.getWeight());
    values.put(COLUMN_BABY_SLEEP,baby.getSleep());
    values.put(COLUMN_BABY_MEDICATE,baby.getMedicate());
    db.insert(TABLE_BABY,null, values);
    db.close();
}


public Cursor getData(){
    SQLiteDatabase db = this.getReadableDatabase();

    Cursor cursor = db.rawQuery(" SELECT * FROM " + TABLE_BABY , null );

    return cursor;
}

以及我插入姓名、生日、性别和年龄的注册活动

try {
    baby.setBaby_name(et_baby.getText().toString());
    baby.setBirthdate(et_date.getText().toString());
    baby.setGender(radioButton.getText().toString());
    baby.setAge("0-3 years");
    dbaseBaby.addBaby(baby);
} catch (Exception e) {
    e.printStackTrace();
}

我想插入高度的活动是

dbaseBaby = new DbaseBaby( Heightone.this);
baby = new Baby();
try {
    baby.setHeight(height.getText().toString()+ "cm");
    dbaseBaby.addBaby(baby);
} catch (Exception e) {
    e.printStackTrace();
}

但是我无法将数据插入一行，注册活动的数据存储在第一行，高度活动的高度存储在第二行 rest 的列设置为 Null。知道在哪里我做错了。

Answer 1

你好，

在第一个活动中你正在创建一个 object 的婴儿并将它插入到数据库（没有高度属性）在第二个活动中你正在创建另一个 object 表格婴儿并将它插入到数据库中（这次只是高度属性和其他为空）实际上你为数据库运行两个独立的插入命令？！（数据库应该如何理解您需要为最后插入的对象添加高度属性？）

解决方案：在第二个活动中，您应该更新以前添加的记录（在第一个活动中）而不是在数据库中添加新的婴儿项目（在第一个活动中使用最后添加的项目的 ID 并在第二个活动中更新该行）

编辑：

每次将新项目添加到 DB addBaby 方法时，都会返回一个长值作为表中添加项目的 ID，您需要捕获它，因此您在SQLiteOpenHelper class中的这个新的addBaby() ：

 public Long addBaby(@NonNull Baby baby){
    SQLiteDatabase db= this.getWritableDatabase();
    ContentValues values = new ContentValues();
    values.put(COLUMN_BABY_NAME,baby.getBaby_name());
    values.put(COLUMN_BABY_DATE,baby.getBirthdate());
    values.put(COLUMN_BABY_GENDER,baby.getGender());
    values.put(COLUMN_BABY_AGE,baby.getAge());
    values.put(COLUMN_BABY_HEIGHT,baby.getHeight());
    values.put(COLUMN_BABY_WEIGHT,baby.getWeight());
    values.put(COLUMN_BABY_SLEEP,baby.getSleep());
    values.put(COLUMN_BABY_MEDICATE,baby.getMedicate());
    Long id = db.insert(TABLE_BABY,null, values);
    db.close();
    return id;
}

每次您将新婴儿添加到表中时，都会像这样返回id ：

   try {
    baby.setBaby_name(et_baby.getText().toString());
    baby.setBirthdate(et_date.getText().toString());
    baby.setGender(radioButton.getText().toString());
    baby.setAge("0-3 years");
    Long id = dbaseBaby.addBaby(baby);
} catch (Exception e) {
    e.printStackTrace();
}

当导航到第二个活动时，将检索到的ID放入意图中并发送到下一个活动：

 Intent intent = new Intent(this,SecondActivity.class);
 intent.putExtra("added_id",id);
 startActivity(intent);

现在在你的SQLiteOpenHelper class 中添加updateHeight 方法：

public void updateHeight(Long id, String height) {
    sqLiteDatabase = this.getWritableDatabase();
    ContentValues cv = new ContentValues();
    cv.put(COLUMN_BABY_HEIGHT,height);
    sqLiteDatabase.update(TableName, cv, "baby_id = ?", new String[]{String.valueOf(id)});

}

最后，您可以在第二个活动中从 intent 中读取 id 并通过此 id，更新最后插入的行并为其添加高度属性：

    dbaseBaby = new DbaseBaby(Heightone.this);
    baby = new Baby();
    Long id = getIntent().getLongExtra("added_id", 0);
    String height = "50cm";
    dbaseBaby.updateHeight(id, height);