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from sqlglot import exp
from sqlglot.dialects.dialect import (
Dialect,
format_time_lambda,
inline_array_sql,
rename_func,
)
from sqlglot.expressions import Literal
from sqlglot.generator import Generator
from sqlglot.helper import list_get
from sqlglot.parser import Parser
from sqlglot.tokens import Tokenizer, TokenType
def _check_int(s):
if s[0] in ("-", "+"):
return s[1:].isdigit()
return s.isdigit()
# from https://docs.snowflake.com/en/sql-reference/functions/to_timestamp.html
def _snowflake_to_timestamp(args):
if len(args) == 2:
first_arg, second_arg = args
if second_arg.is_string:
# case: <string_expr> [ , <format> ]
return format_time_lambda(exp.StrToTime, "snowflake")(args)
# case: <numeric_expr> [ , <scale> ]
if second_arg.name not in ["0", "3", "9"]:
raise ValueError(f"Scale for snowflake numeric timestamp is {second_arg}, but should be 0, 3, or 9")
if second_arg.name == "0":
timescale = exp.UnixToTime.SECONDS
elif second_arg.name == "3":
timescale = exp.UnixToTime.MILLIS
elif second_arg.name == "9":
timescale = exp.UnixToTime.MICROS
return exp.UnixToTime(this=first_arg, scale=timescale)
first_arg = list_get(args, 0)
if not isinstance(first_arg, Literal):
# case: <variant_expr>
return format_time_lambda(exp.StrToTime, "snowflake", default=True)(args)
if first_arg.is_string:
if _check_int(first_arg.this):
# case: <integer>
return exp.UnixToTime.from_arg_list(args)
# case: <date_expr>
return format_time_lambda(exp.StrToTime, "snowflake", default=True)(args)
# case: <numeric_expr>
return exp.UnixToTime.from_arg_list(args)
def _unix_to_time(self, expression):
scale = expression.args.get("scale")
timestamp = self.sql(expression, "this")
if scale in [None, exp.UnixToTime.SECONDS]:
return f"TO_TIMESTAMP({timestamp})"
if scale == exp.UnixToTime.MILLIS:
return f"TO_TIMESTAMP({timestamp}, 3)"
if scale == exp.UnixToTime.MICROS:
return f"TO_TIMESTAMP({timestamp}, 9)"
raise ValueError("Improper scale for timestamp")
# https://docs.snowflake.com/en/sql-reference/functions/date_part.html
# https://docs.snowflake.com/en/sql-reference/functions-date-time.html#label-supported-date-time-parts
def _parse_date_part(self):
this = self._parse_var() or self._parse_type()
self._match(TokenType.COMMA)
expression = self._parse_bitwise()
name = this.name.upper()
if name.startswith("EPOCH"):
if name.startswith("EPOCH_MILLISECOND"):
scale = 10**3
elif name.startswith("EPOCH_MICROSECOND"):
scale = 10**6
elif name.startswith("EPOCH_NANOSECOND"):
scale = 10**9
else:
scale = None
ts = self.expression(exp.Cast, this=expression, to=exp.DataType.build("TIMESTAMP"))
to_unix = self.expression(exp.TimeToUnix, this=ts)
if scale:
to_unix = exp.Mul(this=to_unix, expression=exp.Literal.number(scale))
return to_unix
return self.expression(exp.Extract, this=this, expression=expression)
class Snowflake(Dialect):
null_ordering = "nulls_are_large"
time_format = "'yyyy-mm-dd hh24:mi:ss'"
time_mapping = {
"YYYY": "%Y",
"yyyy": "%Y",
"YY": "%y",
"yy": "%y",
"MMMM": "%B",
"mmmm": "%B",
"MON": "%b",
"mon": "%b",
"MM": "%m",
"mm": "%m",
"DD": "%d",
"dd": "%d",
"d": "%-d",
"DY": "%w",
"dy": "%w",
"HH24": "%H",
"hh24": "%H",
"HH12": "%I",
"hh12": "%I",
"MI": "%M",
"mi": "%M",
"SS": "%S",
"ss": "%S",
"FF": "%f",
"ff": "%f",
"FF6": "%f",
"ff6": "%f",
}
class Parser(Parser):
FUNCTIONS = {
**Parser.FUNCTIONS,
"ARRAYAGG": exp.ArrayAgg.from_arg_list,
"IFF": exp.If.from_arg_list,
"TO_TIMESTAMP": _snowflake_to_timestamp,
"ARRAY_CONSTRUCT": exp.Array.from_arg_list,
"RLIKE": exp.RegexpLike.from_arg_list,
}
FUNCTION_PARSERS = {
**Parser.FUNCTION_PARSERS,
"DATE_PART": _parse_date_part,
}
FUNC_TOKENS = {
*Parser.FUNC_TOKENS,
TokenType.RLIKE,
TokenType.TABLE,
}
COLUMN_OPERATORS = {
**Parser.COLUMN_OPERATORS,
TokenType.COLON: lambda self, this, path: self.expression(
exp.Bracket,
this=this,
expressions=[path],
),
}
PROPERTY_PARSERS = {
**Parser.PROPERTY_PARSERS,
TokenType.PARTITION_BY: lambda self: self._parse_partitioned_by(),
}
class Tokenizer(Tokenizer):
QUOTES = ["'", "$$"]
ESCAPE = "\\"
SINGLE_TOKENS = {
**Tokenizer.SINGLE_TOKENS,
"$": TokenType.PARAMETER,
}
KEYWORDS = {
**Tokenizer.KEYWORDS,
"QUALIFY": TokenType.QUALIFY,
"DOUBLE PRECISION": TokenType.DOUBLE,
"TIMESTAMP_LTZ": TokenType.TIMESTAMPLTZ,
"TIMESTAMP_NTZ": TokenType.TIMESTAMP,
"TIMESTAMP_TZ": TokenType.TIMESTAMPTZ,
"TIMESTAMPNTZ": TokenType.TIMESTAMP,
"SAMPLE": TokenType.TABLE_SAMPLE,
}
class Generator(Generator):
TRANSFORMS = {
**Generator.TRANSFORMS,
exp.ArrayConcat: rename_func("ARRAY_CAT"),
exp.If: rename_func("IFF"),
exp.StrToTime: lambda self, e: f"TO_TIMESTAMP({self.sql(e, 'this')}, {self.format_time(e)})",
exp.UnixToTime: _unix_to_time,
exp.TimeToUnix: lambda self, e: f"EXTRACT(epoch_second FROM {self.sql(e, 'this')})",
exp.Array: inline_array_sql,
exp.StrPosition: rename_func("POSITION"),
exp.Parameter: lambda self, e: f"${self.sql(e, 'this')}",
exp.PartitionedByProperty: lambda self, e: f"PARTITION BY {self.sql(e, 'value')}",
}
TYPE_MAPPING = {
**Generator.TYPE_MAPPING,
exp.DataType.Type.TIMESTAMP: "TIMESTAMPNTZ",
}
ROOT_PROPERTIES = {
exp.PartitionedByProperty,
exp.ReturnsProperty,
exp.LanguageProperty,
exp.SchemaCommentProperty,
exp.ExecuteAsProperty,
exp.VolatilityProperty,
}
def except_op(self, expression):
if not expression.args.get("distinct", False):
self.unsupported("EXCEPT with All is not supported in Snowflake")
return super().except_op(expression)
def intersect_op(self, expression):
if not expression.args.get("distinct", False):
self.unsupported("INTERSECT with All is not supported in Snowflake")
return super().intersect_op(expression)
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