EfCore执行 add-migration ,update-database时出现以下错误，postgres是在哪儿设置的？

[YoChen]

Kdbndp.KingbaseException (0x80004005): 3D000: database "postgres" does not exist at Kdbndp.KdbndpConnector.<>c__DisplayClass166_0.<<ReadMessage>g__ReadMessageLong|0>d.MoveNext() --- End of stack trace from previous location --- at Kdbndp.KdbndpConnector.<>c__DisplayClass166_0.<<ReadMessage>g__ReadMessageLong|0>d.MoveNext() --- End of stack trace from previous location --- at Kdbndp.KdbndpConnector.Open(KdbndpTimeout timeout, Boolean async, CancellationToken cancellationToken) at Kdbndp.KdbndpConnection.<>c__DisplayClass34_0.<<Open>g__OpenLong|0>d.MoveNext() --- End of stack trace from previous location --- at Kdbndp.KdbndpConnection.Open() at Microsoft.EntityFrameworkCore.Storage.RelationalConnection.OpenDbConnection(Boolean errorsExpected) at Microsoft.EntityFrameworkCore.Storage.RelationalConnection.OpenInternal(Boolean errorsExpected) at Microsoft.EntityFrameworkCore.Storage.RelationalConnection.Open(Boolean errorsExpected) at Microsoft.EntityFrameworkCore.Migrations.Internal.MigrationCommandExecutor.ExecuteNonQuery(IEnumerable1 migrationCommands, IRelationalConnection connection) at Kdbndp.EntityFrameworkCore.KingbaseES.Storage.Internal.KdbndpDatabaseCreator.Create() at Microsoft.EntityFrameworkCore.Migrations.Internal.Migrator.Migrate(String targetMigration) at Microsoft.EntityFrameworkCore.Design.Internal.MigrationsOperations.UpdateDatabase(String targetMigration, String connectionString, String contextType) at Microsoft.EntityFrameworkCore.Design.OperationExecutor.UpdateDatabaseImpl(String targetMigration, String connectionString, String contextType) at Microsoft.EntityFrameworkCore.Design.OperationExecutor.UpdateDatabase.<>c__DisplayClass0_0.<.ctor>b__0() at Microsoft.EntityFrameworkCore.Design.OperationExecutor.OperationBase.Execute(Action action) 3D000: database "postgres" does not exist`

[YoChen]

临时解决办法：

新建一个postgres空数据库，然后再执行迁移就可以了。

[YoChen]

`Configure(options => { /* The main point to change your DBMS.

• See also DataDictionaryMigrationsDbContextFactory for EF Core tooling. */ options.UseKdbndp(b => { b.MigrationsHistoryTable("__DataDictionary_Migrations"); b.UseAdminDatabase("kingbase"); }); });`

b.UseAdminDatabase("kingbase"); 或是在配置数据库上下文时增加这句？

[wangpengxpy]

没明白你的问题，看异常信息是连接的数据库postgres不存在

[hatzhang]

根据我使用的经验，这个错会在连接一个不存在的库时出现。如以下连接串

host=localhost;port=4321;database=TestAAA;user id=system;password=123456;

如果TestAAA不存在，就会报这个错。倒不是说postgres这个库不存在。 在使用SqlServer的EFCore时，库不存在会主动创建。不知道Kingbase这个能不能也这样？