[odb-users] How to retrieve schema name ?

[Boris Kolpackov]

Hi David,

Yes, Per got it right, the easiest way to get this information is
to use a view. Section 13.2, "Schema Migration" has the description
of this table:

"... By default, when schema evolution is enabled, ODB maintains this
 information in a special table called schema_version that has the
 following (or equivalent, depending on the database used) definition:"


CREATE TABLE "schema_version" (
  "name" TEXT NOT NULL PRIMARY KEY,
  "version" BIGINT NOT NULL,
  "migration" BOOLEAN NOT NULL);
  

"The name column is the schema name as specified with the --schema-name
 option. It is empty for the default schema. The version column contains the
 current database version. And, finally, the migration flag indicates whether
 we are in the process of migrating the database, that is, between the pre and
 post-migration stages."

One improvement on Per's suggestion would be to use a table view rather
than a native view. A bit less raw SQL:

#pragma db view table("schema_version")
struct schema_name
{
  #pragma db column("name")
  std::string name;
};

Boris