superset/db_engine_specs/exasol.py

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# pylint: disable=C,R,W
from typing import List, Tuple

from superset.db_engine_specs.base import BaseEngineSpec


class ExasolEngineSpec(BaseEngineSpec):
    """Engine spec for Exasol"""

    engine = "exa"
    max_column_name_length = 128

    # Exasol's DATE_TRUNC function is PostgresSQL compatible
    _time_grain_functions = {
        None: "{col}",
        "PT1S": "DATE_TRUNC('second', {col})",
        "PT1M": "DATE_TRUNC('minute', {col})",
        "PT1H": "DATE_TRUNC('hour', {col})",
        "P1D": "DATE_TRUNC('day', {col})",
        "P1W": "DATE_TRUNC('week', {col})",
        "P1M": "DATE_TRUNC('month', {col})",
        "P0.25Y": "DATE_TRUNC('quarter', {col})",
        "P1Y": "DATE_TRUNC('year', {col})",
    }

    @classmethod
    def fetch_data(cls, cursor, limit: int) -> List[Tuple]:
        data = super().fetch_data(cursor, limit)
        # Lists of `pyodbc.Row` need to be unpacked further
        if data and type(data[0]).__name__ == "Row":
            data = [tuple(row) for row in data]
        return data