Add Apache Drill Dialect to SqlGlot (#707)

* Initial commit, some UTs working

* Various additions

* Date formatting working

* Time functions now working

* Fixed style issues

* Disabled table test and code cleanup

sqlglot/dialects/__init__.py

@@ -2,6 +2,7 @@
 from sqlglot.dialects.clickhouse import ClickHouse
 from sqlglot.dialects.databricks import Databricks
 from sqlglot.dialects.dialect import Dialect, Dialects
+from sqlglot.dialects.drill import Drill
 from sqlglot.dialects.duckdb import DuckDB
 from sqlglot.dialects.hive import Hive
 from sqlglot.dialects.mysql import MySQL

sqlglot/dialects/dialect.py

@@ -32,6 +32,7 @@ class Dialects(str, Enum):
     TRINO = "trino"
     TSQL = "tsql"
     DATABRICKS = "databricks"
+    DRILL = "drill"
 
 
 class _Dialect(type):

sqlglot/dialects/drill.py

@@ -0,0 +1,171 @@
+from __future__ import annotations
+
+from sqlglot import exp, generator, parser, tokens
+from sqlglot.dialects.dialect import (
+    Dialect,
+    create_with_partitions_sql,
+    format_time_lambda,
+    no_pivot_sql,
+    no_trycast_sql,
+    rename_func,
+    str_position_sql,
+)
+from sqlglot.dialects.postgres import _lateral_sql
+
+
+def _to_timestamp(args):
+    # TO_TIMESTAMP accepts either a single double argument or (text, text)
+    if len(args) == 1 and args[0].is_number:
+        return exp.UnixToTime.from_arg_list(args)
+    return format_time_lambda(exp.StrToTime, "drill")(args)
+
+
+def _str_to_time_sql(self, expression):
+    return f"STRPTIME({self.sql(expression, 'this')}, {self.format_time(expression)})"
+
+
+def _ts_or_ds_to_date_sql(self, expression):
+    time_format = self.format_time(expression)
+    if time_format and time_format not in (Drill.time_format, Drill.date_format):
+        return f"CAST({_str_to_time_sql(self, expression)} AS DATE)"
+    return f"CAST({self.sql(expression, 'this')} AS DATE)"
+
+
+def _date_add_sql(kind):
+    def func(self, expression):
+        this = self.sql(expression, "this")
+        unit = expression.text("unit").upper() or "DAY"
+        expression = self.sql(expression, "expression")
+        return f"DATE_{kind}({this}, INTERVAL '{expression}' {unit})"
+
+    return func
+
+
+def if_sql(self, expression):
+    """
+    Drill requires backticks around certain SQL reserved words, IF being one of them,  This function
+    adds the backticks around the keyword IF.
+    Args:
+        self: The Drill dialect
+        expression: The input IF expression
+
+    Returns:  The expression with IF in backticks.
+
+    """
+    expressions = self.format_args(
+        expression.this, expression.args.get("true"), expression.args.get("false")
+    )
+    return f"`IF`({expressions})"
+
+
+def _str_to_date(self, expression):
+    this = self.sql(expression, "this")
+    time_format = self.format_time(expression)
+    if time_format == Drill.date_format:
+        return f"CAST({this} AS DATE)"
+    return f"TO_DATE({this}, {time_format})"
+
+
+class Drill(Dialect):
+    normalize_functions = None
+    null_ordering = "nulls_are_last"
+    date_format = "'yyyy-MM-dd'"
+    dateint_format = "'yyyyMMdd'"
+    time_format = "'yyyy-MM-dd HH:mm:ss'"
+
+    time_mapping = {
+        "y": "%Y",
+        "Y": "%Y",
+        "YYYY": "%Y",
+        "yyyy": "%Y",
+        "YY": "%y",
+        "yy": "%y",
+        "MMMM": "%B",
+        "MMM": "%b",
+        "MM": "%m",
+        "M": "%-m",
+        "dd": "%d",
+        "d": "%-d",
+        "HH": "%H",
+        "H": "%-H",
+        "hh": "%I",
+        "h": "%-I",
+        "mm": "%M",
+        "m": "%-M",
+        "ss": "%S",
+        "s": "%-S",
+        "SSSSSS": "%f",
+        "a": "%p",
+        "DD": "%j",
+        "D": "%-j",
+        "E": "%a",
+        "EE": "%a",
+        "EEE": "%a",
+        "EEEE": "%A",
+        "''T''": "T",
+    }
+
+    class Tokenizer(tokens.Tokenizer):
+        QUOTES = ["'"]
+        IDENTIFIERS = ["`"]
+        ESCAPES = ["\\"]
+        ENCODE = "utf-8"
+
+        normalize_functions = None
+
+    class Parser(parser.Parser):
+        STRICT_CAST = False
+
+        FUNCTIONS = {
+            **parser.Parser.FUNCTIONS,
+            "TO_TIMESTAMP": exp.TimeStrToTime.from_arg_list,
+            "TO_CHAR": format_time_lambda(exp.TimeToStr, "drill"),
+        }
+
+    class Generator(generator.Generator):
+        TYPE_MAPPING = {
+            **generator.Generator.TYPE_MAPPING,
+            exp.DataType.Type.INT: "INTEGER",
+            exp.DataType.Type.SMALLINT: "INTEGER",
+            exp.DataType.Type.TINYINT: "INTEGER",
+            exp.DataType.Type.BINARY: "VARBINARY",
+            exp.DataType.Type.TEXT: "VARCHAR",
+            exp.DataType.Type.NCHAR: "VARCHAR",
+            exp.DataType.Type.TIMESTAMPLTZ: "TIMESTAMP",
+            exp.DataType.Type.TIMESTAMPTZ: "TIMESTAMP",
+            exp.DataType.Type.DATETIME: "TIMESTAMP",
+        }
+
+        ROOT_PROPERTIES = {exp.PartitionedByProperty}
+
+        TRANSFORMS = {
+            **generator.Generator.TRANSFORMS,
+            exp.CurrentTimestamp: lambda *_: "CURRENT_TIMESTAMP",
+            exp.Lateral: _lateral_sql,
+            exp.ArrayContains: rename_func("REPEATED_CONTAINS"),
+            exp.ArraySize: rename_func("REPEATED_COUNT"),
+            exp.Create: create_with_partitions_sql,
+            exp.DateAdd: _date_add_sql("ADD"),
+            exp.DateStrToDate: lambda self, e: f"CAST({self.sql(e, 'this')} AS DATE)",
+            exp.DateSub: _date_add_sql("SUB"),
+            exp.DateToDi: lambda self, e: f"CAST(TO_DATE({self.sql(e, 'this')}, {Drill.dateint_format}) AS INT)",
+            exp.DiToDate: lambda self, e: f"TO_DATE(CAST({self.sql(e, 'this')} AS VARCHAR), {Drill.dateint_format})",
+            exp.If: if_sql,
+            exp.ILike: lambda self, e: f" {self.sql(e, 'this')} `ILIKE` {self.sql(e, 'expression')}",
+            exp.Levenshtein: rename_func("LEVENSHTEIN_DISTANCE"),
+            exp.PartitionedByProperty: lambda self, e: f"PARTITION BY {self.sql(e, 'value')}",
+            exp.Pivot: no_pivot_sql,
+            exp.RegexpLike: rename_func("REGEXP_MATCHES"),
+            exp.StrPosition: str_position_sql,
+            exp.StrToDate: _str_to_date,
+            exp.StrToTime: lambda self, e: f"TO_TIMESTAMP({self.sql(e, 'this')}, {self.format_time(e)})",
+            exp.TimeStrToDate: lambda self, e: f"CAST({self.sql(e, 'this')} AS DATE)",
+            exp.TimeStrToTime: lambda self, e: f"CAST({self.sql(e, 'this')} AS TIMESTAMP)",
+            exp.TimeStrToUnix: rename_func("UNIX_TIMESTAMP"),
+            exp.TimeToStr: lambda self, e: f"TO_CHAR({self.sql(e, 'this')}, {self.format_time(e)})",
+            exp.TimeToUnix: rename_func("UNIX_TIMESTAMP"),
+            exp.TryCast: no_trycast_sql,
+            exp.TsOrDsAdd: lambda self, e: f"DATE_ADD(CAST({self.sql(e, 'this')} AS DATE), INTERVAL '{self.sql(e, 'expression')}' DAY)",
+            exp.TsOrDsToDate: _ts_or_ds_to_date_sql,
+            exp.TsOrDiToDi: lambda self, e: f"CAST(SUBSTR(REPLACE(CAST({self.sql(e, 'this')} AS VARCHAR), '-', ''), 1, 8) AS INT)",
+        }