superset/db_engine_specs/db2.py

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from superset.constants import TimeGrain
from superset.db_engine_specs.base import BaseEngineSpec, LimitMethod


class Db2EngineSpec(BaseEngineSpec):
    engine = "db2"
    engine_aliases = {"ibm_db_sa"}
    engine_name = "IBM Db2"
    limit_method = LimitMethod.WRAP_SQL
    force_column_alias_quotes = True
    max_column_name_length = 30

    _time_grain_expressions = {
        None: "{col}",
        TimeGrain.SECOND: "CAST({col} as TIMESTAMP) - MICROSECOND({col}) MICROSECONDS",
        TimeGrain.MINUTE: "CAST({col} as TIMESTAMP)"
        " - SECOND({col}) SECONDS"
        " - MICROSECOND({col}) MICROSECONDS",
        TimeGrain.HOUR: "CAST({col} as TIMESTAMP)"
        " - MINUTE({col}) MINUTES"
        " - SECOND({col}) SECONDS"
        " - MICROSECOND({col}) MICROSECONDS ",
        TimeGrain.DAY: "CAST({col} as TIMESTAMP)"
        " - HOUR({col}) HOURS"
        " - MINUTE({col}) MINUTES"
        " - SECOND({col}) SECONDS"
        " - MICROSECOND({col}) MICROSECONDS",
        TimeGrain.WEEK: "{col} - (DAYOFWEEK({col})) DAYS",
        TimeGrain.MONTH: "{col} - (DAY({col})-1) DAYS",
        TimeGrain.QUARTER: "{col} - (DAY({col})-1) DAYS"
        " - (MONTH({col})-1) MONTHS"
        " + ((QUARTER({col})-1) * 3) MONTHS",
        TimeGrain.YEAR: "{col} - (DAY({col})-1) DAYS - (MONTH({col})-1) MONTHS",
    }

    @classmethod
    def epoch_to_dttm(cls) -> str:
        return "(TIMESTAMP('1970-01-01', '00:00:00') + {col} SECONDS)"