Error Classes¶

RickDb defines three exception classes for different error categories.

rick_db.RecordError¶

Raised by the object mapper when record operations fail.

from rick_db import RecordError

Raised when:

load() is called with an unknown attribute name
pk() is called on a record without a primary key definition

from rick_db import fieldmapper, RecordError

@fieldmapper(tablename="users", pk="id_user")
class User:
    id = "id_user"
    name = "name"

try:
    user = User()
    user.load(nonexistent_field="value")
except RecordError as e:
    print("Record error:", e)

rick_db.DbConnectionError¶

Raised for connection and transaction errors.

from rick_db import DbConnectionError

Raised when:

begin() is called while autocommit is enabled
begin() is called when a transaction is already open

from rick_db import DbConnectionError

try:
    conn.begin()
    conn.begin()  # raises DbConnectionError: transaction already open
except DbConnectionError as e:
    print("Connection error:", e)

A backward-compatibility alias ConnectionError exists but should not be used in new code, as it shadows Python's builtin ConnectionError:

from rick_db import DbConnectionError

# Preferred
try:
    conn.begin()
except DbConnectionError:
    pass

# Deprecated alias (avoid — shadows builtin)
# from rick_db import ConnectionError

rick_db.sql.SqlError¶

Raised by the query builder for SQL generation errors.

from rick_db.sql import SqlError

Raised when:

where() receives an invalid field type
where() receives an empty list for IN/NOT IN
group() detects duplicate group fields
assemble() is called with unbalanced where_and()/where_or()/where_end() blocks
Insert.assemble() detects a field/value count mismatch
page() receives a page number less than 1

from rick_db.sql import Select, PgSqlDialect, SqlError

try:
    # Empty IN list raises SqlError
    Select(PgSqlDialect()).from_("users").where("id", "IN", []).assemble()
except SqlError as e:
    print("SQL error:", e)

try:
    # Unbalanced parentheses
    Select(PgSqlDialect()).from_("users").where_and().where("a", "=", 1).assemble()
except SqlError as e:
    print("SQL error:", e)

Exception hierarchy¶

All three exceptions extend Python's Exception directly:

Exception
├── RecordError       (rick_db)
├── DbConnectionError (rick_db)
└── SqlError          (rick_db.sql)