Entity Framework Core 引入了方法 HasServiceTier和 HasPerformanceLevel更改 Azure SQL 服务器的版本。您可以在 OnModelCreating 中使用它们像这样:
protected override void OnModelCreating(ModelBuilder modelBuilder)
{
base.OnModelCreating(modelBuilder);
modelBuilder.HasServiceTier("Basic");
modelBuilder.HasPerformanceLevel("Basic");
}
如果您使用 Add-Migration Add-Migration你会得到这样的迁移:
public partial class ChangedDatabaseServiceTierToBasic : Migration
{
protected override void Up(MigrationBuilder migrationBuilder)
{
migrationBuilder.AlterDatabase()
.Annotation("SqlServer:EditionOptions", "EDITION = 'Basic', SERVICE_OBJECTIVE = 'Basic'");
}
protected override void Down(MigrationBuilder migrationBuilder)
{
migrationBuilder.AlterDatabase()
.OldAnnotation("SqlServer:EditionOptions", "EDITION = 'Basic', SERVICE_OBJECTIVE = 'Basic'");
}
}
这似乎工作正常,但当我尝试将此迁移应用于本地非 Azure 数据库以进行开发时,我收到以下错误:
Microsoft.EntityFrameworkCore.Migrations[20402]
Applying migration '20200413102908_ChangedDatabaseServiceTierToBasic'.
Applying migration '20200413102908_ChangedDatabaseServiceTierToBasic'.
fail: Microsoft.EntityFrameworkCore.Database.Command[20102]
Failed executing DbCommand (3ms) [Parameters=[], CommandType='Text', CommandTimeout='30']
BEGIN
DECLARE @db_name NVARCHAR(MAX) = DB_NAME();
EXEC(N'ALTER DATABASE ' + @db_name + ' MODIFY (
EDITION = ''Basic'', SERVICE_OBJECTIVE = ''Basic'' );');
END
Failed executing DbCommand (3ms) [Parameters=[], CommandType='Text', CommandTimeout='30']
BEGIN
DECLARE @db_name NVARCHAR(MAX) = DB_NAME();
EXEC(N'ALTER DATABASE ' + @db_name + ' MODIFY (
EDITION = ''Basic'', SERVICE_OBJECTIVE = ''Basic'' );');
END
Microsoft.Data.SqlClient.SqlException (0x80131904): Incorrect syntax near '.'.
at Microsoft.Data.SqlClient.SqlConnection.OnError(SqlException exception, Boolean breakConnection, Action`1 wrapCloseInAction)
at Microsoft.Data.SqlClient.SqlInternalConnection.OnError(SqlException exception, Boolean breakConnection, Action`1 wrapCloseInAction)
at Microsoft.Data.SqlClient.TdsParser.ThrowExceptionAndWarning(TdsParserStateObject stateObj, Boolean callerHasConnectionLock, Boolean asyncClose)
at Microsoft.Data.SqlClient.TdsParser.TryRun(RunBehavior runBehavior, SqlCommand cmdHandler, SqlDataReader dataStream, BulkCopySimpleResultSet bulkCopyHandler, TdsParserStateObject stateObj, Boolean& dataReady)
at Microsoft.Data.SqlClient.SqlCommand.RunExecuteNonQueryTds(String methodName, Boolean isAsync, Int32 timeout, Boolean asyncWrite)
at Microsoft.Data.SqlClient.SqlCommand.InternalExecuteNonQuery(TaskCompletionSource`1 completion, Boolean sendToPipe, Int32 timeout, Boolean& usedCache, Boolean asyncWrite, Boolean inRetry, String methodName)
at Microsoft.Data.SqlClient.SqlCommand.ExecuteNonQuery()
at Microsoft.EntityFrameworkCore.Storage.RelationalCommand.ExecuteNonQuery(RelationalCommandParameterObject parameterObject)
at Microsoft.EntityFrameworkCore.Migrations.MigrationCommand.ExecuteNonQuery(IRelationalConnection connection, IReadOnlyDictionary`2 parameterValues)
at Microsoft.EntityFrameworkCore.Migrations.Internal.MigrationCommandExecutor.ExecuteNonQuery(IEnumerable`1 migrationCommands, IRelationalConnection connection)
at Microsoft.EntityFrameworkCore.Migrations.Internal.Migrator.Migrate(String targetMigration)
at Microsoft.EntityFrameworkCore.Design.Internal.MigrationsOperations.UpdateDatabase(String targetMigration, String contextType)
at Microsoft.EntityFrameworkCore.Design.OperationExecutor.UpdateDatabaseImpl(String targetMigration, String contextType)
at Microsoft.EntityFrameworkCore.Design.OperationExecutor.UpdateDatabase.<>c__DisplayClass0_0.<.ctor>b__0()
at Microsoft.EntityFrameworkCore.Design.OperationExecutor.OperationBase.Execute(Action action)
ClientConnectionId:d9f92b81-9916-48ee-9686-6d0f567ab86f
Error Number:102,State:1,Class:15
Incorrect syntax near '.'.
我假设这些命令对于非 Azure 数据库无效。所以问题是:如何防止这些命令在非 Azure DB 上执行?
最佳答案
EF Core 团队现已意识到该问题并将其添加到他们的待办事项中: https://github.com/dotnet/efcore/issues/20682
同时,官方推荐的解决方法如下所示:
migrationBuilder.Sql(@"IF SERVERPROPERTY('EngineEdition') = 5
EXEC(N'ALTER DATABASE [ThreeOne.SomeDbContext] MODIFY (EDITION = ''Basic'', SERVICE_OBJECTIVE = ''Basic'' );');
");
我修改它以在不知道当前数据库名称的情况下工作:
migrationBuilder.Sql
(
@"declare @dbname varchar(100)
set @dbname=quotename(db_name())
IF SERVERPROPERTY('EngineEdition') = 5
EXEC(N'ALTER DATABASE '+@dbname+' MODIFY (EDITION = ''Basic'', SERVICE_OBJECTIVE = ''Basic'' );');"
);
关于c# - 在 EF Core 中指定 Azure SQL Server 版本而不破坏本地开发,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/61205031/