如何使用ormLite在android中的现有实体中添加新字段?
作者:互联网
OLENT ENTITY:我有一个实体,我忘了在某些字段上添加@DatabaseField注释
@DatabaseTable
public class Card {
@DatabaseField(generatedId = true)
private int id;
@DatabaseField(unique = true)
private String cardNumber;
@DatabaseField
private String nameOnCard;
private String ccv;
private String validFrom;
private String validTill;
private String pin;
//Required by ormLite
public Card() {
}
//skipped the getter setters below
}
我有一个写配置的类,这里是代码.
package net.udevs.db;
import com.j256.ormlite.android.apptools.OrmLiteConfigUtil;
import net.udevs.entity.Card;
public class OrmLiteSqlLiteConfigGenerator extends OrmLiteConfigUtil {
private final static Class<?>[] entityClasses=new Class[]{EmailAccount.class, Card.class};
public static void main(String... args) throws Exception{
writeConfigFile("ormlite_config.txt",entityClasses);
}
}
生成的配置文件低于&通过查看它我知道数据库中的字段没有更新.
#
# generated on 2016/01/14 01:13:56
#
# --table-start--
dataClass=net.udevs.entity.Card
tableName=card
# --table-fields-start--
# --field-start--
fieldName=id
generatedId=true
# --field-end--
# --field-start--
fieldName=cardNumber
unique=true
# --field-end--
# --field-start--
fieldName=nameOnCard
# --field-end--
# --table-fields-end--
# --table-end--
#################################
NEW ENTITY:现在我添加了缺少的@DatabaseField注释.
public class Card {
@DatabaseField(generatedId = true)
private int id;
@DatabaseField(unique = true)
private String cardNumber;
@DatabaseField
private String nameOnCard;
@DatabaseField
private String ccv;
@DatabaseField
private String validFrom;
@DatabaseField
private String validTill;
@DatabaseField
private String pin;
public Card() {
}
public Card(int id, String cardNumber, String nameOnCard, String ccv, String validFrom, String validTill, String pin) {
this.id = id;
this.cardNumber = cardNumber;
this.nameOnCard = nameOnCard;
this.ccv = ccv;
this.validFrom = validFrom;
this.validTill = validTill;
this.pin = pin;
}
//skipped the getter setters below
}
&安培;然后我再次运行OrmLiteConfigUtil类,但配置文件没有改变.
解决方法:
您可以将@DatabaseField注释添加到缺少的字段并增加数据库版本,然后在onUpgrade方法中执行此操作
@Override
public void onUpgrade(SQLiteDatabase db, ConnectionSource connectionSource, int oldVersion, int newVersion) {
if(oldVersion == 1) {
try {
Dao dao = getCardDao();
dao.executeRaw("ALTER TABLE `Card` ADD COLUMN ccv STRING;");
dao.executeRaw("ALTER TABLE `Card` ADD COLUMN validFrom STRING;");
} catch (SQLException e) {
Log.e(DatabaseHelper.class.getName(), "Error ", e);
}
}
}
最后运行OrmLiteConfigUtil,配置文本文件将更改.
通过这种方式,您不必擦除数据库并丢失数据.
标签:android,ormlite 来源: https://codeday.me/bug/20190829/1760853.html