具有复杂 Json 结构的房间
Room with complex Json structure
我是 Room 的新手，目前正在做我的一个项目，我应该在其中插入一些改造 GSON 数据。首先，让我在下面展示我的JSON，这将给出一个清晰的结构。
{
"organization": {
"id": 0,
"title": "string",
"description": "HTML String",
"style": {
"navigationBackgroundColor": "#cd1325",
"navigationTextColor": "#ffffff",
"topBarLabel": "27July2015abcd",
"topBarBackgroundColor": "#cd1325",
"topBarTextColor": "#ffffff",
"bodyBackgroundColor": "#f5c233",
"bodyTextColor": "#646363",
"bannerBackgroundColor": "#ffffff",
"bannerTextColor": "#000000",
"buttonBackgroundColor": "#000000",
"buttonTextColor": "#ffffff",
"baseTextSize": 0,
"htmlWrapper": "string"
}
"login_options": [{
"name": "string",
"title": "EMAIL",
"description": "string",
"state": "string",
"allowed_email_domain": "string",
"restricted_email_domain": "string"
}, {
"name": "string",
"titl"e: "GOOGLE",
"description": "string",
"url": "string",
"clientId": "string",
"clientSecret": "string",
"redirectUri": "string",
"state": "string",
"nonce": "string",
"authorizationEndpointUri": "string",
"tokenEndpointUri": "string"
}
]
}
}
我正在使用效果很好的改造来解析它。以下是从 https://www.jsonschema2pojo.org/
创建的模型 类 名称
好的。现在我必须通过我的存储库将它们插入到 Room 数据库中，为此我遇到了很多困难。任何人都可以帮助我如何创建实体以及如何将这些数据模型插入房间。仍然不确定是将 GSON 模型插入 Room 还是创建实体并将解析数据放入其中然后插入。
我到目前为止所尝试的。
登录选项表
@Parcelize
@Entity
public class LoginOptionsTable {
@ColumnInfo
@PrimaryKey(autoGenerate = true)
public long loginOpnId;
@ColumnInfo(name = "login_options_name")
public String name;
@ColumnInfo(name = "login_options_title")
public String title;
@ColumnInfo(name = "login_options_description")
public String description;
@ColumnInfo
public String state;
@ColumnInfo
public String allowedEmailDomain;
@ColumnInfo
public String restrictedEmailDomain;
@ColumnInfo
public String url;
@ColumnInfo
public String clientId;
@ColumnInfo
public String clientSecret;
@ColumnInfo
public String redirectUri;
@ColumnInfo
public String nonce;
@ColumnInfo
public String authorizationEndpointUri;
@ColumnInfo
public String tokenEndpointUri;
public static List<LoginOptionsTable> fromObject(List<LoginOption>
mOptions){
List<LoginOptionsTable> groups = new ArrayList<>();
for(int i=0; i<mOptions.size(); i++){
LoginOptionsTable st = new LoginOptionsTable();
st.name = mOptions.get(i).getName();
st.title = mOptions.get(i).getTitle();
st.description = mOptions.get(i).getDescription();
st.state = mOptions.get(i).getState();
st.allowedEmailDomain = mOptions.get(i).getAllowedEmailDomain();
st.restrictedEmailDomain =
mOptions.get(i).getRestrictedEmailDomain();
st.url = mOptions.get(i).getUrl();
st.clientId = mOptions.get(i).getClientId();
st.clientSecret = mOptions.get(i).getClientSecret();
st.redirectUri = mOptions.get(i).getRedirectUri();
st.nonce = mOptions.get(i).getNonce();
st.authorizationEndpointUri =
mOptions.get(i).getAuthorizationEndpointUri();
st.tokenEndpointUri = mOptions.get(i).getTokenEndpointUri();
groups.add(st);
}
return groups;
}
}
样式实体：
@Parcelize
@Entity
public class StyleTable {
@ColumnInfo
@PrimaryKey(autoGenerate = true)
public long styleId;
@ColumnInfo
public String navigationBackgroundColor;
@ColumnInfo
public String navigationTextColor;
@ColumnInfo
public String topBarLabel;
@ColumnInfo
public String topBarBackgroundColor;
@ColumnInfo
public String topBarTextColor;
@ColumnInfo
public String bodyBackgroundColor;
@ColumnInfo
public String bodyTextColor;
@ColumnInfo
public String bannerBackgroundColor;
@ColumnInfo
public String bannerTextColor;
@ColumnInfo
public String buttonBackgroundColor;
@ColumnInfo
public String buttonTextColor;
@ColumnInfo
public Integer baseTextSize;
@ColumnInfo
public String htmlWrapper;
public static StyleTable fromObject(Style mStyle) {
StyleTable st = new StyleTable();
st.navigationBackgroundColor = mStyle.getNavigationBackgroundColor();
st.navigationTextColor = mStyle.getNavigationTextColor();
st.topBarLabel = mStyle.getTopBarLabel();
st.topBarBackgroundColor = mStyle.getTopBarBackgroundColor();
st.topBarTextColor = mStyle.getTopBarTextColor();
st.bannerBackgroundColor = mStyle.getBodyBackgroundColor();
st.bannerTextColor = mStyle.getBannerTextColor();
st.buttonBackgroundColor = mStyle.getButtonBackgroundColor();
st.buttonTextColor = mStyle.getButtonTextColor();
st.baseTextSize = mStyle.getBaseTextSize();
st.htmlWrapper = mStyle.getHtmlWrapper();
return st;
}
}
组织实体：
@Parcelize
@Entity(foreignKeys = {@ForeignKey(entity = StyleTable.class, parentColumns =
"styleId", childColumns = "stId"),
@ForeignKey(entity = LoginOptionsTable.class, parentColumns =
"loginOptionId", childColumns = "loginOpnId")
})
public class OrgTable {
@ColumnInfo
@PrimaryKey
public long id;
@ColumnInfo
public String title;
@ColumnInfo
public String description;
@ColumnInfo
public long stId;
//TODo make it for mutiple table
@ColumnInfo
public Long loginOptionsId;
@Ignore
public StyleTable style;
@Ignore
public List<LoginOptionsTable> loginOptions = null;
public static OrgTable fromObject(Organization organization){
OrgTable org = new OrgTable();
org.id = organization.getId();
org.title = organization.getTitle();
org.description = organization.getDescription();
StyleTable st = StyleTable.fromObject(organization.getStyle());
org.style = st;
//make the relation through Id
org.stId = st.styleId;
List<LoginOptionsTable> lo =
LoginOptionsTable.fromObject(organization.getLoginOptions());
org.loginOptions = lo;
//make the relation through Id
org.loginOptionsId = lo.get(0).loginOpnId;
return org;
}
}
DAO
@Dao
public interface OrgDAO {
@Query("SELECT * FROM OrgTable")
OrgTable getOrganization();
@Insert
void insertOrg(OrgTable org);
}
我试图创建这些，但无法理解如何保持这些与 insert/get 保存数据之间的关系。
I have tried to create these, but not able to understand how to keep the relation between these and insert/get the saved data.
您可以通过以下两种方式执行此操作：
一个包含所有三个表的 POJO @Embedded（仅适用于 1 Org -> 1 Login and 1 Style）
带有 OrgTable @Embedded 的 POJO 以及带有 @Relation 注释的 LoginOptionsTable 和 StyleTable
第一个（所有三个表 @Embedded）的示例是：-
class OrgWithLoginAndStyle {
/* Note use Query that
JOINS the Orgtable with the Login table
and JOINS the Orgtable with the Style table
*/
@Embedded
OrgTable orgTable;
@Embedded
LoginOptionsTable loginOptionsTable;
@Embedded
StyleTable styleTable;
}
一个利用这个的 Dao 的例子是：-
@Query("SELECT * FROM OrgTable " +
"JOIN StyleTable ON StyleTable.styleId = OrgTable.stId " +
"JOIN LoginOptionsTable ON LoginOptionsTable.loginOpnId = OrgTable.loginOptionsId")
List<OrgWithLoginAndStyle> getOrganizationLoginAndStyle();
- 这是更灵活的查询方式，因为所有列都可用于 WHERE 子句等，但查询更复杂。
第二个示例（带有对 LoginOptionsTable 和 StyleTable 的 @Relation 注释）:-
class OrganizationWithLoginOptionsAndWithStyles {
@Embedded
OrgTable orgTable;
@Relation(entity = LoginOptionsTable.class,parentColumn = "loginOptionsId",entityColumn = "loginOpnId")
List<LoginOptionsTable> loginOptionsTables;
@Relation(entity = StyleTable.class,parentColumn = "stId",entityColumn = "styleId")
List<StyleTable> styleTables;
}
- 这可能更易于编码。但是，它的效率较低，因为样式和登录选项是为每个 OrgTable 独立检索的。因此，查询更简单，因为您只需要获取 OrgTable(s)。 Room 负责构建相关对象。查询仅限于 OrgTable 列上的 WHERE 等（如果您加入其他表，则此类子句可能不会获得所需的结果（在您的情况下可能没问题，因为每个 OrgTable 对象只有 1 个 LoginOptions 和 1 个 Style））
一个利用这个的 Dao 的例子是：-
@Transaction
@Query("SELECT * FROM OrgTable")
List<OrganizationWithLoginOptionsAndWithStyles> getOrganizationsLoginsAndStyles();
- 请注意，由于（我相信）基础查询是 运行 获取 LoginOptionsTable 对象和 StyleTable 对象，因此建议使用 @Transaction。
备注
关于您的 getOrganization 查询（见评论）
@Query("SELECT * FROM OrgTable")
//OrgTable getOrganization(); /* <<<<<<<<<< WRONG should be a List */
List<OrgTable> getOrganizations();
还有你的insertOrg
@Insert
//void insertOrg(OrgTable org)
long insertOrg(OrgTable org); /* <<<<<<<<<< might as well allow the id of the inserted row to be obtained */
Ok. Now I have to insert these into the Room database through my repository for which I am facing a lot of difficulties.
而且我相信您的 OrgTable FK 定义应该符合 :-
@Entity(foreignKeys = {@ForeignKey(entity = StyleTable.class, parentColumns =
"styleId", childColumns = "stId"),
@ForeignKey(entity = LoginOptionsTable.class, parentColumns =
"loginOpnId", childColumns = "loginOptionsId")
})
- 即 LoginOptions child 和 parent 是错误的方式，而且 parent 应该是 loginOptionsId 而不是 loginOptionId（在 Option 之后不是 s）。
基础测试
除了使 OrgDao class :-
之外，使用上面的以下代码
@Dao
public interface OrgDAO {
@Query("SELECT * FROM OrgTable")
//OrgTable getOrganization(); /* <<<<<<<<<< WRONG should be a List */
List<OrgTable> getOrganizations();
@Query("SELECT * FROM OrgTable " +
"JOIN StyleTable ON StyleTable.styleId = OrgTable.stId " +
"JOIN LoginOptionsTable ON LoginOptionsTable.loginOpnId = OrgTable.loginOptionsId")
List<OrgWithLoginAndStyle> getOrganizationLoginAndStyle();
@Transaction
@Query("SELECT * FROM OrgTable")
List<OrganizationWithLoginOptionsAndWithStyles> getOrganizationsLoginsAndStyles();
@Insert
//void insertOrg(OrgTable org)
long insertOrg(OrgTable org); /* <<<<<<<<<< might as well allow the id of the inserted row to be obtained */
@Insert
long insertStyle(StyleTable styleTable);
@Insert
long insertLoginOptions(LoginOptionsTable loginOptionsTable);
}
并使用 :-
@Database(entities = {OrgTable.class,StyleTable.class,LoginOptionsTable.class},version = 1)
抽象 class OrgLoginStyleDatabase 扩展 RoomDatabase {
抽象 OrgDAO getOrgDao();
}
还有 activity（请注意，您的一些代码已被注释掉，即使用 @Parcelize 和实体的 @Ignored Constructors）：-
public class MainActivity extends AppCompatActivity {
OrgLoginStyleDatabase db;
OrgDAO dao;
public static final String TAG = "OLSINFO";
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
db = Room.databaseBuilder(this,OrgLoginStyleDatabase.class,"orgloginoptionsstyle.db")
.allowMainThreadQueries()
.build();
dao = db.getOrgDao();
StyleTable s1 = new StyleTable();
s1.bannerBackgroundColor = "X";
s1.bannerTextColor = "X";
s1.baseTextSize = 20;
s1.bodyBackgroundColor = "X";
s1.bodyTextColor = "X";
s1.buttonBackgroundColor = "X";
s1.buttonTextColor = "X";
s1.htmlWrapper = "X";
s1.navigationBackgroundColor = "X";
s1.navigationTextColor = "X";
s1.styleId = 100;
s1.topBarBackgroundColor = "X";
s1.topBarLabel = "X";
s1.topBarTextColor = "X";
long s1Id = dao.insertStyle(s1);
LoginOptionsTable l1 = new LoginOptionsTable();
l1.allowedEmailDomain = "Y";
l1.authorizationEndpointUri = "Y";
l1.clientId = "Y";
l1.clientSecret = "Y";
l1.description = "Y";
l1.loginOpnId = 1000;
l1.name = "Y";
l1.nonce = "Y";
l1.redirectUri = "Y";
l1.restrictedEmailDomain = "Y";
l1.state = "Y";
l1.title = "Y";
l1.url = "Y";
long l1Id = dao.insertLoginOptions(l1);
OrgTable o1 = new OrgTable();
o1.description = "Z";
o1.id = 10000;
o1.loginOptionsId = l1Id;
o1.stId = s1Id;
dao.insertOrg(o1);
List<OrgTable> orgTableList = dao.getOrganizations();
for(OrgTable o: orgTableList) {
logOrgTable(o,"FROM getOrganizations -> ");
}
List<OrganizationWithLoginOptionsAndWithStyles> organizationsLoginsAndStylesList = dao.getOrganizationsLoginsAndStyles();
for(OrganizationWithLoginOptionsAndWithStyles owloaws: organizationsLoginsAndStylesList) {
logOrgTable(owloaws.orgTable,"FROM (@Relations) getOrganizationsLoginsAndStyles -> ");
for(LoginOptionsTable lot: owloaws.loginOptionsTables) {
logLoginOptionsTable(lot,"\t");
}
for(StyleTable s: owloaws.styleTables) {
logStyleTable(s,"\t");
}
}
List<OrgWithLoginAndStyle> owlas = dao.getOrganizationLoginAndStyle();
for(OrgWithLoginAndStyle o: owlas) {
logOrgTable(o.orgTable,"FROM (@Embeddeds) getOrganizationLoginAndStyle -> ");
logLoginOptionsTable(o.loginOptionsTable,"\t");
logStyleTable(o.styleTable,"\t");
}
}
private void logOrgTable(OrgTable o,String preamble) {
Log.d(TAG,preamble + "OrgTable Description = " + o.description + " ID = " + o.id);
}
private void logStyleTable(StyleTable s, String preamble) {
Log.d(TAG,preamble + "StyleTable Description = " + s.topBarTextColor + " ID =" + s.styleId);
}
private void logLoginOptionsTable(LoginOptionsTable l, String preamble) {
Log.d(TAG,preamble + "LoginOptionsTable Description = " + l.description + " ID = " + l.loginOpnId);
}
}
结果
当运行时（只会运行曾经使用过的硬编码ID）输出到日志的结果是：-
2021-04-12 21:51:50.981 D/OLSINFO: FROM getOrganizations -> OrgTable Description = Z ID = 10000
2021-04-12 21:51:50.987 D/OLSINFO: FROM (@Relations) getOrganizationsLoginsAndStyles -> OrgTable Description = Z ID = 10000
2021-04-12 21:51:50.987 D/OLSINFO: LoginOptionsTable Description = Y ID = 1000
2021-04-12 21:51:50.987 D/OLSINFO: StyleTable Description = X ID =100
2021-04-12 21:51:50.989 D/OLSINFO: FROM (@Embeddeds) getOrganizationLoginAndStyle -> OrgTable Description = Z ID = 10000
2021-04-12 21:51:50.989 D/OLSINFO: LoginOptionsTable Description = Y ID = 1000
2021-04-12 21:51:50.989 D/OLSINFO: StyleTable Description = X ID =100
- 所有三个对象都已成功插入，所有三个查询都按预期工作。
我是 Room 的新手，目前正在做我的一个项目，我应该在其中插入一些改造 GSON 数据。首先，让我在下面展示我的JSON，这将给出一个清晰的结构。
{
"organization": {
"id": 0,
"title": "string",
"description": "HTML String",
"style": {
"navigationBackgroundColor": "#cd1325",
"navigationTextColor": "#ffffff",
"topBarLabel": "27July2015abcd",
"topBarBackgroundColor": "#cd1325",
"topBarTextColor": "#ffffff",
"bodyBackgroundColor": "#f5c233",
"bodyTextColor": "#646363",
"bannerBackgroundColor": "#ffffff",
"bannerTextColor": "#000000",
"buttonBackgroundColor": "#000000",
"buttonTextColor": "#ffffff",
"baseTextSize": 0,
"htmlWrapper": "string"
}
"login_options": [{
"name": "string",
"title": "EMAIL",
"description": "string",
"state": "string",
"allowed_email_domain": "string",
"restricted_email_domain": "string"
}, {
"name": "string",
"titl"e: "GOOGLE",
"description": "string",
"url": "string",
"clientId": "string",
"clientSecret": "string",
"redirectUri": "string",
"state": "string",
"nonce": "string",
"authorizationEndpointUri": "string",
"tokenEndpointUri": "string"
}
]
}
}
我正在使用效果很好的改造来解析它。以下是从 https://www.jsonschema2pojo.org/
创建的模型 类 名称好的。现在我必须通过我的存储库将它们插入到 Room 数据库中，为此我遇到了很多困难。任何人都可以帮助我如何创建实体以及如何将这些数据模型插入房间。仍然不确定是将 GSON 模型插入 Room 还是创建实体并将解析数据放入其中然后插入。 我到目前为止所尝试的。
登录选项表
@Parcelize
@Entity
public class LoginOptionsTable {
@ColumnInfo
@PrimaryKey(autoGenerate = true)
public long loginOpnId;
@ColumnInfo(name = "login_options_name")
public String name;
@ColumnInfo(name = "login_options_title")
public String title;
@ColumnInfo(name = "login_options_description")
public String description;
@ColumnInfo
public String state;
@ColumnInfo
public String allowedEmailDomain;
@ColumnInfo
public String restrictedEmailDomain;
@ColumnInfo
public String url;
@ColumnInfo
public String clientId;
@ColumnInfo
public String clientSecret;
@ColumnInfo
public String redirectUri;
@ColumnInfo
public String nonce;
@ColumnInfo
public String authorizationEndpointUri;
@ColumnInfo
public String tokenEndpointUri;
public static List<LoginOptionsTable> fromObject(List<LoginOption>
mOptions){
List<LoginOptionsTable> groups = new ArrayList<>();
for(int i=0; i<mOptions.size(); i++){
LoginOptionsTable st = new LoginOptionsTable();
st.name = mOptions.get(i).getName();
st.title = mOptions.get(i).getTitle();
st.description = mOptions.get(i).getDescription();
st.state = mOptions.get(i).getState();
st.allowedEmailDomain = mOptions.get(i).getAllowedEmailDomain();
st.restrictedEmailDomain =
mOptions.get(i).getRestrictedEmailDomain();
st.url = mOptions.get(i).getUrl();
st.clientId = mOptions.get(i).getClientId();
st.clientSecret = mOptions.get(i).getClientSecret();
st.redirectUri = mOptions.get(i).getRedirectUri();
st.nonce = mOptions.get(i).getNonce();
st.authorizationEndpointUri =
mOptions.get(i).getAuthorizationEndpointUri();
st.tokenEndpointUri = mOptions.get(i).getTokenEndpointUri();
groups.add(st);
}
return groups;
}
}
样式实体：
@Parcelize
@Entity
public class StyleTable {
@ColumnInfo
@PrimaryKey(autoGenerate = true)
public long styleId;
@ColumnInfo
public String navigationBackgroundColor;
@ColumnInfo
public String navigationTextColor;
@ColumnInfo
public String topBarLabel;
@ColumnInfo
public String topBarBackgroundColor;
@ColumnInfo
public String topBarTextColor;
@ColumnInfo
public String bodyBackgroundColor;
@ColumnInfo
public String bodyTextColor;
@ColumnInfo
public String bannerBackgroundColor;
@ColumnInfo
public String bannerTextColor;
@ColumnInfo
public String buttonBackgroundColor;
@ColumnInfo
public String buttonTextColor;
@ColumnInfo
public Integer baseTextSize;
@ColumnInfo
public String htmlWrapper;
public static StyleTable fromObject(Style mStyle) {
StyleTable st = new StyleTable();
st.navigationBackgroundColor = mStyle.getNavigationBackgroundColor();
st.navigationTextColor = mStyle.getNavigationTextColor();
st.topBarLabel = mStyle.getTopBarLabel();
st.topBarBackgroundColor = mStyle.getTopBarBackgroundColor();
st.topBarTextColor = mStyle.getTopBarTextColor();
st.bannerBackgroundColor = mStyle.getBodyBackgroundColor();
st.bannerTextColor = mStyle.getBannerTextColor();
st.buttonBackgroundColor = mStyle.getButtonBackgroundColor();
st.buttonTextColor = mStyle.getButtonTextColor();
st.baseTextSize = mStyle.getBaseTextSize();
st.htmlWrapper = mStyle.getHtmlWrapper();
return st;
}
}
组织实体：
@Parcelize
@Entity(foreignKeys = {@ForeignKey(entity = StyleTable.class, parentColumns =
"styleId", childColumns = "stId"),
@ForeignKey(entity = LoginOptionsTable.class, parentColumns =
"loginOptionId", childColumns = "loginOpnId")
})
public class OrgTable {
@ColumnInfo
@PrimaryKey
public long id;
@ColumnInfo
public String title;
@ColumnInfo
public String description;
@ColumnInfo
public long stId;
//TODo make it for mutiple table
@ColumnInfo
public Long loginOptionsId;
@Ignore
public StyleTable style;
@Ignore
public List<LoginOptionsTable> loginOptions = null;
public static OrgTable fromObject(Organization organization){
OrgTable org = new OrgTable();
org.id = organization.getId();
org.title = organization.getTitle();
org.description = organization.getDescription();
StyleTable st = StyleTable.fromObject(organization.getStyle());
org.style = st;
//make the relation through Id
org.stId = st.styleId;
List<LoginOptionsTable> lo =
LoginOptionsTable.fromObject(organization.getLoginOptions());
org.loginOptions = lo;
//make the relation through Id
org.loginOptionsId = lo.get(0).loginOpnId;
return org;
}
}
DAO
@Dao
public interface OrgDAO {
@Query("SELECT * FROM OrgTable")
OrgTable getOrganization();
@Insert
void insertOrg(OrgTable org);
}
我试图创建这些，但无法理解如何保持这些与 insert/get 保存数据之间的关系。
I have tried to create these, but not able to understand how to keep the relation between these and insert/get the saved data.
您可以通过以下两种方式执行此操作：
一个包含所有三个表的 POJO
@Embedded（仅适用于 1 Org -> 1 Login and 1 Style）带有 OrgTable
@Embedded的 POJO 以及带有@Relation注释的 LoginOptionsTable 和 StyleTable
第一个（所有三个表 @Embedded）的示例是：-
class OrgWithLoginAndStyle {
/* Note use Query that
JOINS the Orgtable with the Login table
and JOINS the Orgtable with the Style table
*/
@Embedded
OrgTable orgTable;
@Embedded
LoginOptionsTable loginOptionsTable;
@Embedded
StyleTable styleTable;
}
一个利用这个的 Dao 的例子是：-
@Query("SELECT * FROM OrgTable " +
"JOIN StyleTable ON StyleTable.styleId = OrgTable.stId " +
"JOIN LoginOptionsTable ON LoginOptionsTable.loginOpnId = OrgTable.loginOptionsId")
List<OrgWithLoginAndStyle> getOrganizationLoginAndStyle();
- 这是更灵活的查询方式，因为所有列都可用于 WHERE 子句等，但查询更复杂。
第二个示例（带有对 LoginOptionsTable 和 StyleTable 的 @Relation 注释）:-
class OrganizationWithLoginOptionsAndWithStyles {
@Embedded
OrgTable orgTable;
@Relation(entity = LoginOptionsTable.class,parentColumn = "loginOptionsId",entityColumn = "loginOpnId")
List<LoginOptionsTable> loginOptionsTables;
@Relation(entity = StyleTable.class,parentColumn = "stId",entityColumn = "styleId")
List<StyleTable> styleTables;
}
- 这可能更易于编码。但是，它的效率较低，因为样式和登录选项是为每个 OrgTable 独立检索的。因此，查询更简单，因为您只需要获取 OrgTable(s)。 Room 负责构建相关对象。查询仅限于 OrgTable 列上的 WHERE 等（如果您加入其他表，则此类子句可能不会获得所需的结果（在您的情况下可能没问题，因为每个 OrgTable 对象只有 1 个 LoginOptions 和 1 个 Style））
一个利用这个的 Dao 的例子是：-
@Transaction
@Query("SELECT * FROM OrgTable")
List<OrganizationWithLoginOptionsAndWithStyles> getOrganizationsLoginsAndStyles();
- 请注意，由于（我相信）基础查询是 运行 获取 LoginOptionsTable 对象和 StyleTable 对象，因此建议使用 @Transaction。
备注
关于您的 getOrganization 查询（见评论）
@Query("SELECT * FROM OrgTable")
//OrgTable getOrganization(); /* <<<<<<<<<< WRONG should be a List */
List<OrgTable> getOrganizations();
还有你的insertOrg
@Insert
//void insertOrg(OrgTable org)
long insertOrg(OrgTable org); /* <<<<<<<<<< might as well allow the id of the inserted row to be obtained */
Ok. Now I have to insert these into the Room database through my repository for which I am facing a lot of difficulties.
而且我相信您的 OrgTable FK 定义应该符合 :-
@Entity(foreignKeys = {@ForeignKey(entity = StyleTable.class, parentColumns =
"styleId", childColumns = "stId"),
@ForeignKey(entity = LoginOptionsTable.class, parentColumns =
"loginOpnId", childColumns = "loginOptionsId")
})
- 即 LoginOptions child 和 parent 是错误的方式，而且 parent 应该是 loginOptionsId 而不是 loginOptionId（在 Option 之后不是 s）。
基础测试
除了使 OrgDao class :-
之外，使用上面的以下代码@Dao
public interface OrgDAO {
@Query("SELECT * FROM OrgTable")
//OrgTable getOrganization(); /* <<<<<<<<<< WRONG should be a List */
List<OrgTable> getOrganizations();
@Query("SELECT * FROM OrgTable " +
"JOIN StyleTable ON StyleTable.styleId = OrgTable.stId " +
"JOIN LoginOptionsTable ON LoginOptionsTable.loginOpnId = OrgTable.loginOptionsId")
List<OrgWithLoginAndStyle> getOrganizationLoginAndStyle();
@Transaction
@Query("SELECT * FROM OrgTable")
List<OrganizationWithLoginOptionsAndWithStyles> getOrganizationsLoginsAndStyles();
@Insert
//void insertOrg(OrgTable org)
long insertOrg(OrgTable org); /* <<<<<<<<<< might as well allow the id of the inserted row to be obtained */
@Insert
long insertStyle(StyleTable styleTable);
@Insert
long insertLoginOptions(LoginOptionsTable loginOptionsTable);
}
并使用 :-
@Database(entities = {OrgTable.class,StyleTable.class,LoginOptionsTable.class},version = 1) 抽象 class OrgLoginStyleDatabase 扩展 RoomDatabase { 抽象 OrgDAO getOrgDao(); }
还有 activity（请注意，您的一些代码已被注释掉，即使用 @Parcelize 和实体的 @Ignored Constructors）：-
public class MainActivity extends AppCompatActivity {
OrgLoginStyleDatabase db;
OrgDAO dao;
public static final String TAG = "OLSINFO";
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
db = Room.databaseBuilder(this,OrgLoginStyleDatabase.class,"orgloginoptionsstyle.db")
.allowMainThreadQueries()
.build();
dao = db.getOrgDao();
StyleTable s1 = new StyleTable();
s1.bannerBackgroundColor = "X";
s1.bannerTextColor = "X";
s1.baseTextSize = 20;
s1.bodyBackgroundColor = "X";
s1.bodyTextColor = "X";
s1.buttonBackgroundColor = "X";
s1.buttonTextColor = "X";
s1.htmlWrapper = "X";
s1.navigationBackgroundColor = "X";
s1.navigationTextColor = "X";
s1.styleId = 100;
s1.topBarBackgroundColor = "X";
s1.topBarLabel = "X";
s1.topBarTextColor = "X";
long s1Id = dao.insertStyle(s1);
LoginOptionsTable l1 = new LoginOptionsTable();
l1.allowedEmailDomain = "Y";
l1.authorizationEndpointUri = "Y";
l1.clientId = "Y";
l1.clientSecret = "Y";
l1.description = "Y";
l1.loginOpnId = 1000;
l1.name = "Y";
l1.nonce = "Y";
l1.redirectUri = "Y";
l1.restrictedEmailDomain = "Y";
l1.state = "Y";
l1.title = "Y";
l1.url = "Y";
long l1Id = dao.insertLoginOptions(l1);
OrgTable o1 = new OrgTable();
o1.description = "Z";
o1.id = 10000;
o1.loginOptionsId = l1Id;
o1.stId = s1Id;
dao.insertOrg(o1);
List<OrgTable> orgTableList = dao.getOrganizations();
for(OrgTable o: orgTableList) {
logOrgTable(o,"FROM getOrganizations -> ");
}
List<OrganizationWithLoginOptionsAndWithStyles> organizationsLoginsAndStylesList = dao.getOrganizationsLoginsAndStyles();
for(OrganizationWithLoginOptionsAndWithStyles owloaws: organizationsLoginsAndStylesList) {
logOrgTable(owloaws.orgTable,"FROM (@Relations) getOrganizationsLoginsAndStyles -> ");
for(LoginOptionsTable lot: owloaws.loginOptionsTables) {
logLoginOptionsTable(lot,"\t");
}
for(StyleTable s: owloaws.styleTables) {
logStyleTable(s,"\t");
}
}
List<OrgWithLoginAndStyle> owlas = dao.getOrganizationLoginAndStyle();
for(OrgWithLoginAndStyle o: owlas) {
logOrgTable(o.orgTable,"FROM (@Embeddeds) getOrganizationLoginAndStyle -> ");
logLoginOptionsTable(o.loginOptionsTable,"\t");
logStyleTable(o.styleTable,"\t");
}
}
private void logOrgTable(OrgTable o,String preamble) {
Log.d(TAG,preamble + "OrgTable Description = " + o.description + " ID = " + o.id);
}
private void logStyleTable(StyleTable s, String preamble) {
Log.d(TAG,preamble + "StyleTable Description = " + s.topBarTextColor + " ID =" + s.styleId);
}
private void logLoginOptionsTable(LoginOptionsTable l, String preamble) {
Log.d(TAG,preamble + "LoginOptionsTable Description = " + l.description + " ID = " + l.loginOpnId);
}
}
结果
当运行时（只会运行曾经使用过的硬编码ID）输出到日志的结果是：-
2021-04-12 21:51:50.981 D/OLSINFO: FROM getOrganizations -> OrgTable Description = Z ID = 10000
2021-04-12 21:51:50.987 D/OLSINFO: FROM (@Relations) getOrganizationsLoginsAndStyles -> OrgTable Description = Z ID = 10000
2021-04-12 21:51:50.987 D/OLSINFO: LoginOptionsTable Description = Y ID = 1000
2021-04-12 21:51:50.987 D/OLSINFO: StyleTable Description = X ID =100
2021-04-12 21:51:50.989 D/OLSINFO: FROM (@Embeddeds) getOrganizationLoginAndStyle -> OrgTable Description = Z ID = 10000
2021-04-12 21:51:50.989 D/OLSINFO: LoginOptionsTable Description = Y ID = 1000
2021-04-12 21:51:50.989 D/OLSINFO: StyleTable Description = X ID =100
- 所有三个对象都已成功插入，所有三个查询都按预期工作。