SeaQL/sea-orm · error

not implemented

Error message

not implemented

What it means

build_postgres_stmt! builds the statement only when the backend is Postgres; for MySql or Sqlite it calls unimplemented!() as a hard guard. The panic means a Postgres-only query/feature (e.g. PostgreSQL-specific SQL construction like returning clauses or locks) was sent through this helper against a non-Postgres backend. The at-fault input is a DbBackend::MySql/Sqlite backend reaching a Postgres-specific statement builder.

Source

Thrown at sea-orm-sync/src/database/statement.rs:112

        }
    }
}

macro_rules! build_any_stmt {
    ($stmt: expr, $db_backend: expr) => {
        match $db_backend {
            DbBackend::MySql => $stmt.build(MysqlQueryBuilder),
            DbBackend::Postgres => $stmt.build(PostgresQueryBuilder),
            DbBackend::Sqlite => $stmt.build(SqliteQueryBuilder),
        }
    };
}

macro_rules! build_postgres_stmt {
    ($stmt: expr, $db_backend: expr) => {
        match $db_backend {
            DbBackend::Postgres => $stmt.to_string(PostgresQueryBuilder),
            DbBackend::MySql | DbBackend::Sqlite => unimplemented!(),
        }
    };
}

macro_rules! build_query_stmt {
    ($stmt: ty) => {
        impl StatementBuilder for $stmt {
            fn build(&self, db_backend: &DbBackend) -> Statement {
                let stmt = build_any_stmt!(self, db_backend);
                Statement::from_string_values_tuple(*db_backend, stmt)
            }

            #[cfg(feature = "rbac")]
            fn audit(&self) -> Result<QueryAccessAudit, AuditError> {
                AuditTrait::audit(self)
            }
        }
    };

View on GitHub (pinned to e29bcd1b41)

Solutions

  1. Only invoke the Postgres-specific statement builder when DbBackend is Postgres; branch on backend beforehand.
  2. Use build_any_stmt! or the generic query builder path for MySQL/SQLite support.
  3. If the feature is genuinely Postgres-only, gate the calling code path on the sqlx-postgres feature/backend so other backends never reach it.

Example fix

// before
let sql = pg_only_stmt.to_string(&db_backend)?;
// after
if db_backend != DbBackend::Postgres { return Err(UnsupportedBackend(db_backend)); }
let sql = pg_only_stmt.to_string(PostgresQueryBuilder);
Defensive patterns

Strategy: validation

Validate before calling

fn backend_supported(b: &sea_orm::DbBackend) -> bool {
    matches!(b, sea_orm::DbBackend::Postgres)
}

Type guard

fn is_postgres(b: &sea_orm::DbBackend) -> bool { matches!(b, sea_orm::DbBackend::Postgres) }

Try / catch

// guard before building
if !is_postgres(&backend) { return Err(MyError::UnsupportedBackend(backend.clone())); }

Prevention

When it happens

Trigger: Calling build/to_string on a statement type registered with build_postgres_stmt! while the target backend is MySql or Sqlite in the synchronous crate.

Common situations: Sync apps using Postgres-specific statements against MySQL/SQLite; portable code paths that do not gate on DbBackend.

Understand the failure class

Background: "unsupported platform" / "not supported on this platform" errors: what they mean and how to fix them — this error's family across 47 libraries.

Related errors

AI-assisted analysis of SeaQL/sea-orm@e29bcd1b41 (2026-09-10). Data as JSON: /api/errors/104833deb1384a9d. Report an issue: GitHub.