SeaQL/sea-orm · error

not implemented

Error message

not implemented

What it means

build_postgres_stmt! in src/database/statement.rs only renders its statement with the Postgres query builder; for DbBackend::MySql or Sqlite it calls unimplemented!(). The statement types registered with this macro have no SQL rendering for those backends.

Source

Thrown at 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. Use the statement only with a Postgres backend; check DbBackend before building
  2. Use a portable sea_query statement/builder variant for MySQL/SQLite
  3. Split backend-specific code paths so the wrong backend never reaches this statement

Example fix

// before
let sql = pg_only_stmt.to_string(&db_backend)?; // panics on MySql/Sqlite
// after
assert_eq!(db_backend, DbBackend::Postgres);
let sql = pg_only_stmt.to_string(PostgresQueryBuilder);
Defensive patterns

Strategy: validation

Validate before calling

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

Type guard

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

Try / catch

// unimplemented!() panics; check backend first
if is_postgres(&db_backend) { let sql = pg_only_stmt.to_string(&db_backend); } else { /* portable path */ }

Prevention

When it happens

Trigger: Building (calling .to_string()/build on) a statement whose type is compiled via build_postgres_stmt! while the connection backend is DbBackend::MySql or DbBackend::Sqlite.

Common situations: Using Postgres-only statement types while connected to MySQL or SQLite; sharing statement-building code across backends without a backend check.

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/556c8a3781aac7ea. Report an issue: GitHub.