summaryrefslogtreecommitdiffstats
path: root/sqlglot/dialects/sqlite.py
blob: b292c81c40b52934fcd980bded446f78033a041c (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
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"