DataError properties

[yohanboniface]

Hi,

Is there any way to access/populate the DataError properties (eg. column_name) as for other exceptions (eg. NotNullViolationError) ?

Here is a quick script to demonstrate my point:

import asyncio
import asyncpg
import datetime


async def main():
    conn = await asyncpg.connect("postgresql://postgres@localhost/test")
    await conn.execute(
        """
        CREATE TABLE IF NOT EXISTS users(
            id serial PRIMARY KEY,
            name text,
            dob date NOT NULL,
            foo integer
        )
    """
    )

   # With a NotNullViolationError
    try:
        await conn.execute(
            """
            INSERT INTO users(name, dob, foo) VALUES($1, $2, $3)
        """,
            "Bob",
            None,
            42
        )
    except asyncpg.NotNullViolationError as err:
        print(err.as_dict())
        # Will print:
        # {'severity': 'ERROR', 'severity_en': 'ERROR', 'sqlstate': '23502', 'message': 'null value in column "dob" violates not-null constraint', 
        # 'detail': 'Failing row contains (3, Bob, null, 12).', 'schema_name': 'public', 'table_name': 'users', 
        # 'column_name': 'dob', 'server_source_filename': 'execMain.c', 'server_source_line': '2008', 
        # 'server_source_function': 'ExecConstraints'}

    # With a DataError.
    try:
        await conn.execute(
            """
            INSERT INTO users(name, dob, foo) VALUES($1, $2, $3)
        """,
            "Bob",
            datetime.datetime(2018, 10, 10),
            "invalid"
        )
    except asyncpg.DataError as err:
        print(err.as_dict())
        # Will print, with no more details:
        # {'sqlstate': '22000'}

asyncio.get_event_loop().run_until_complete(main())

Thanks! :)

[elprans]

That DataError comes from asyncpg, not from postgres itself and is the result of invalid input representation of a data type. Short of parsing the input query, we cannot say that the input was actually destined to a specific column in an INSERT statement.

[yohanboniface]

OK, thanks!

Maybe once #196 is out we can name the field attached to an error?