Adding 'GO' statements to Entity Framework migrations - sql

Question

So I have an application with a ton of migrations made by Entity framework.
We want to get a script for all the migrations at once and using the -Script tag does work fine.
However...it does not add GO statements in the SQL giving us problems like Alter view should be the first statement in a batch file...
I have been searching around and manually adding Sql("GO"); help with this problem but only for the entire script. When I use the package console manager again it returns an exception.
System.Data.SqlClient.SqlException (0x80131904): Could not find stored procedure 'GO'.
Is there a way to add these GO tags only when using the -Script tag?
If not, what is a good approach for this?
Note: we have also tried having multiple files but since we have so many migrations, this is near impossible to maintain every time.

Answer 1

If you are trying to alter your view using Sql("Alter View dbo.Foos As etc"), then you can avoid the should be the first statement in a batch file error without adding GO statements by putting the sql inside an EXEC command:
Sql("EXEC('Alter View dbo.Foos As etc')")

Answer 2

In order to change the SQL Generated by entity framework migrations you can create a new SqlServerMigrationSqlGenerator
We have done this to add a GO statement before and after the migration history:
public class MigrationScriptBuilder: SqlServerMigrationSqlGenerator
{
protected override void Generate(System.Data.Entity.Migrations.Model.InsertHistoryOperation insertHistoryOperation)
{
Statement("GO");
base.Generate(insertHistoryOperation);
Statement("GO");
}
}
then add in the Configuration constructor (in the Migrations folder of the project where you DbContext is) so that it uses this new sql generator:
[...]
internal sealed class Configuration : DbMigrationsConfiguration<PMA.Dal.PmaContext>
{
public Configuration()
{
SetSqlGenerator("System.Data.SqlClient", new MigrationScriptBuilder());
AutomaticMigrationsEnabled = false;
}
[...]
So now when you generate a script using the -Script tag, you can see that the insert into [__MigrationHistory] is surrounded by GO
Alternatively in your implementation of SqlServerMigrationSqlGenerator you can override any part of the script generation, the InsertHistoryOperation was suitable for us.

Answer 3

Turn out the concept exist deep in the SqlServerMigrationSqlGenerator as an optional argument for Statement(sql, batchTerminator). Here is something based on Skyp idea. It works both in -script mode or not. The GOs are for different operations than for Skyp only because our needs are a little different. You then need to register this class in the Configuration as per Skyp instructions.
public class MigrationScriptBuilder : SqlServerMigrationSqlGenerator
{
private string Marker = Guid.NewGuid().ToString(); //To cheat on the check null or empty of the base generator
protected override void Generate(AlterProcedureOperation alterProcedureOperation)
{
SqlGo();
base.Generate(alterProcedureOperation);
SqlGo();
}
protected override void Generate(CreateProcedureOperation createProcedureOperation)
{
SqlGo();
base.Generate(createProcedureOperation);
SqlGo();
}
protected override void Generate(SqlOperation sqlOperation)
{
SqlGo();
base.Generate(sqlOperation);
}
private void SqlGo()
{
Statement(Marker, batchTerminator: "GO");
}
public override IEnumerable<MigrationStatement> Generate(IEnumerable<MigrationOperation> migrationOperations, string providerManifestToken)
{
var result = new List<MigrationStatement>();
var statements = base.Generate(migrationOperations, providerManifestToken);
bool pendingBatchTerminator = false;
foreach (var item in statements)
{
if(item.Sql == Marker && item.BatchTerminator == "GO")
{
pendingBatchTerminator = true;
}
else
{
if(pendingBatchTerminator)
{
item.BatchTerminator = "GO";
pendingBatchTerminator = false;
}
result.Add(item);
}
}
return result;
}
}

Answer 4

The easiest way is to add /**/ before the GO statement.

Answer 5

Just replace the current statement with a .Replace("GO", "");