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from __future__ import annotations
import typing as t
from sqlglot import exp, generator, parser, tokens, transforms
from sqlglot.dialects.dialect import (
Dialect,
NormalizationStrategy,
any_value_to_max_sql,
arrow_json_extract_sql,
concat_to_dpipe_sql,
count_if_to_sum,
no_ilike_sql,
no_pivot_sql,
no_tablesample_sql,
no_trycast_sql,
rename_func,
)
from sqlglot.tokens import TokenType
def _date_add_sql(self: SQLite.Generator, expression: exp.DateAdd) -> str:
modifier = expression.expression
modifier = modifier.name if modifier.is_string else self.sql(modifier)
unit = expression.args.get("unit")
modifier = f"'{modifier} {unit.name}'" if unit else f"'{modifier}'"
return self.func("DATE", expression.this, modifier)
def _json_extract_sql(self: SQLite.Generator, expression: exp.JSONExtract) -> str:
if expression.expressions:
return self.function_fallback_sql(expression)
return arrow_json_extract_sql(self, expression)
def _transform_create(expression: exp.Expression) -> exp.Expression:
"""Move primary key to a column and enforce auto_increment on primary keys."""
schema = expression.this
if isinstance(expression, exp.Create) and isinstance(schema, exp.Schema):
defs = {}
primary_key = None
for e in schema.expressions:
if isinstance(e, exp.ColumnDef):
defs[e.name] = e
elif isinstance(e, exp.PrimaryKey):
primary_key = e
if primary_key and len(primary_key.expressions) == 1:
column = defs[primary_key.expressions[0].name]
column.append(
"constraints", exp.ColumnConstraint(kind=exp.PrimaryKeyColumnConstraint())
)
schema.expressions.remove(primary_key)
else:
for column in defs.values():
auto_increment = None
for constraint in column.constraints:
if isinstance(constraint.kind, exp.PrimaryKeyColumnConstraint):
break
if isinstance(constraint.kind, exp.AutoIncrementColumnConstraint):
auto_increment = constraint
if auto_increment:
column.constraints.remove(auto_increment)
return expression
class SQLite(Dialect):
# https://sqlite.org/forum/forumpost/5e575586ac5c711b?raw
NORMALIZATION_STRATEGY = NormalizationStrategy.CASE_INSENSITIVE
SUPPORTS_SEMI_ANTI_JOIN = False
TYPED_DIVISION = True
SAFE_DIVISION = True
class Tokenizer(tokens.Tokenizer):
IDENTIFIERS = ['"', ("[", "]"), "`"]
HEX_STRINGS = [("x'", "'"), ("X'", "'"), ("0x", ""), ("0X", "")]
class Parser(parser.Parser):
FUNCTIONS = {
**parser.Parser.FUNCTIONS,
"EDITDIST3": exp.Levenshtein.from_arg_list,
}
STRING_ALIASES = True
class Generator(generator.Generator):
JOIN_HINTS = False
TABLE_HINTS = False
QUERY_HINTS = False
NVL2_SUPPORTED = False
JSON_PATH_BRACKETED_KEY_SUPPORTED = False
SUPPORTS_CREATE_TABLE_LIKE = False
SUPPORTED_JSON_PATH_PARTS = {
exp.JSONPathKey,
exp.JSONPathRoot,
exp.JSONPathSubscript,
}
TYPE_MAPPING = {
**generator.Generator.TYPE_MAPPING,
exp.DataType.Type.BOOLEAN: "INTEGER",
exp.DataType.Type.TINYINT: "INTEGER",
exp.DataType.Type.SMALLINT: "INTEGER",
exp.DataType.Type.INT: "INTEGER",
exp.DataType.Type.BIGINT: "INTEGER",
exp.DataType.Type.FLOAT: "REAL",
exp.DataType.Type.DOUBLE: "REAL",
exp.DataType.Type.DECIMAL: "REAL",
exp.DataType.Type.CHAR: "TEXT",
exp.DataType.Type.NCHAR: "TEXT",
exp.DataType.Type.VARCHAR: "TEXT",
exp.DataType.Type.NVARCHAR: "TEXT",
exp.DataType.Type.BINARY: "BLOB",
exp.DataType.Type.VARBINARY: "BLOB",
}
TOKEN_MAPPING = {
TokenType.AUTO_INCREMENT: "AUTOINCREMENT",
}
TRANSFORMS = {
**generator.Generator.TRANSFORMS,
exp.AnyValue: any_value_to_max_sql,
exp.Concat: concat_to_dpipe_sql,
exp.CountIf: count_if_to_sum,
exp.Create: transforms.preprocess([_transform_create]),
exp.CurrentDate: lambda *_: "CURRENT_DATE",
exp.CurrentTime: lambda *_: "CURRENT_TIME",
exp.CurrentTimestamp: lambda *_: "CURRENT_TIMESTAMP",
exp.DateAdd: _date_add_sql,
exp.DateStrToDate: lambda self, e: self.sql(e, "this"),
exp.ILike: no_ilike_sql,
exp.JSONExtract: _json_extract_sql,
exp.JSONExtractScalar: arrow_json_extract_sql,
exp.Levenshtein: rename_func("EDITDIST3"),
exp.LogicalOr: rename_func("MAX"),
exp.LogicalAnd: rename_func("MIN"),
exp.Pivot: no_pivot_sql,
exp.Rand: rename_func("RANDOM"),
exp.Select: transforms.preprocess(
[
transforms.eliminate_distinct_on,
transforms.eliminate_qualify,
transforms.eliminate_semi_and_anti_joins,
]
),
exp.TableSample: no_tablesample_sql,
exp.TimeStrToTime: lambda self, e: self.sql(e, "this"),
exp.TryCast: no_trycast_sql,
}
# SQLite doesn't generally support CREATE TABLE .. properties
# https://www.sqlite.org/lang_createtable.html
PROPERTIES_LOCATION = {
prop: exp.Properties.Location.UNSUPPORTED
for prop in generator.Generator.PROPERTIES_LOCATION
}
# There are a few exceptions (e.g. temporary tables) which are supported or
# can be transpiled to SQLite, so we explicitly override them accordingly
PROPERTIES_LOCATION[exp.LikeProperty] = exp.Properties.Location.POST_SCHEMA
PROPERTIES_LOCATION[exp.TemporaryProperty] = exp.Properties.Location.POST_CREATE
LIMIT_FETCH = "LIMIT"
def cast_sql(self, expression: exp.Cast, safe_prefix: t.Optional[str] = None) -> str:
if expression.is_type("date"):
return self.func("DATE", expression.this)
return super().cast_sql(expression)
def datediff_sql(self, expression: exp.DateDiff) -> str:
unit = expression.args.get("unit")
unit = unit.name.upper() if unit else "DAY"
sql = f"(JULIANDAY({self.sql(expression, 'this')}) - JULIANDAY({self.sql(expression, 'expression')}))"
if unit == "MONTH":
sql = f"{sql} / 30.0"
elif unit == "YEAR":
sql = f"{sql} / 365.0"
elif unit == "HOUR":
sql = f"{sql} * 24.0"
elif unit == "MINUTE":
sql = f"{sql} * 1440.0"
elif unit == "SECOND":
sql = f"{sql} * 86400.0"
elif unit == "MILLISECOND":
sql = f"{sql} * 86400000.0"
elif unit == "MICROSECOND":
sql = f"{sql} * 86400000000.0"
elif unit == "NANOSECOND":
sql = f"{sql} * 8640000000000.0"
else:
self.unsupported("DATEDIFF unsupported for '{unit}'.")
return f"CAST({sql} AS INTEGER)"
# https://www.sqlite.org/lang_aggfunc.html#group_concat
def groupconcat_sql(self, expression: exp.GroupConcat) -> str:
this = expression.this
distinct = expression.find(exp.Distinct)
if distinct:
this = distinct.expressions[0]
distinct_sql = "DISTINCT "
else:
distinct_sql = ""
if isinstance(expression.this, exp.Order):
self.unsupported("SQLite GROUP_CONCAT doesn't support ORDER BY.")
if expression.this.this and not distinct:
this = expression.this.this
separator = expression.args.get("separator")
return f"GROUP_CONCAT({distinct_sql}{self.format_args(this, separator)})"
def least_sql(self, expression: exp.Least) -> str:
if len(expression.expressions) > 1:
return rename_func("MIN")(self, expression)
return self.sql(expression, "this")
def transaction_sql(self, expression: exp.Transaction) -> str:
this = expression.this
this = f" {this}" if this else ""
return f"BEGIN{this} TRANSACTION"
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