fix(mysql): transpile CHAR (#2329)

tobymao · Sep 26, 2023 · 8242a2c · 8242a2c
1 parent ebdfc59
commit 8242a2c
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Showing 4 changed files with 36 additions and 0 deletions.
diff --git a/sqlglot/dialects/mysql.py b/sqlglot/dialects/mysql.py
@@ -248,6 +248,7 @@ class Parser(parser.Parser):
 
         FUNCTION_PARSERS = {
             **parser.Parser.FUNCTION_PARSERS,
+            "CHAR": lambda self: self._parse_chr(),
             "GROUP_CONCAT": lambda self: self.expression(
                 exp.GroupConcat,
                 this=self._parse_lambda(),
@@ -531,6 +532,18 @@ def _parse_type(self, parse_interval: bool = True) -> t.Optional[exp.Expression]
 
             return super()._parse_type(parse_interval=parse_interval)
 
+        def _parse_chr(self) -> t.Optional[exp.Expression]:
+            expressions = self._parse_csv(self._parse_conjunction)
+            kwargs: t.Dict[str, t.Any] = {"this": seq_get(expressions, 0)}
+
+            if len(expressions) > 1:
+                kwargs["expressions"] = expressions[1:]
+
+            if self._match(TokenType.USING):
+                kwargs["charset"] = self._parse_var()
+
+            return self.expression(exp.Chr, **kwargs)
+
     class Generator(generator.Generator):
         LOCKING_READS_SUPPORTED = True
         NULL_ORDERING_SUPPORTED = False
@@ -717,3 +730,9 @@ def _oldstyle_limit_sql(self, expression: exp.Show) -> str:
                 limit_offset = f"{offset}, {limit}" if offset else limit
                 return f" LIMIT {limit_offset}"
             return ""
+
+        def chr_sql(self, expression: exp.Chr) -> str:
+            this = self.expressions(sqls=[expression.this] + expression.expressions)
+            charset = expression.args.get("charset")
+            using = f" USING {self.sql(charset)}" if charset else ""
+            return f"CHAR({this}{using})"
diff --git a/sqlglot/expressions.py b/sqlglot/expressions.py
@@ -4293,6 +4293,12 @@ class Coalesce(Func):
     _sql_names = ["COALESCE", "IFNULL", "NVL"]
 
 
+class Chr(Func):
+    arg_types = {"this": True, "charset": False, "expressions": False}
+    is_var_len_args = True
+    _sql_names = ["CHR", "CHAR"]
+
+
 class Concat(Func):
     arg_types = {"expressions": True}
     is_var_len_args = True

diff --git a/tests/dialects/test_mysql.py b/tests/dialects/test_mysql.py
@@ -205,6 +205,9 @@ def test_identity(self):
         )
         self.validate_identity("INTERVAL '1' YEAR")
         self.validate_identity("DATE_ADD(x, INTERVAL 1 YEAR)")
+        self.validate_identity("CHAR(0)")
+        self.validate_identity("CHAR(77, 121, 83, 81, '76')")
+        self.validate_identity("CHAR(77, 77.3, '77.3' USING utf8mb4)")
 
     def test_types(self):
         self.validate_identity("CAST(x AS MEDIUMINT) + CAST(y AS YEAR(4))")
@@ -244,6 +247,13 @@ def test_canonical_functions(self):
         self.validate_identity(
             "SELECT WEEK_OF_YEAR('2023-01-01')", "SELECT WEEKOFYEAR('2023-01-01')"
         )
+        self.validate_all(
+            "CHAR(10)",
+            write={
+                "mysql": "CHAR(10)",
+                "presto": "CHR(10)",
+            },
+        )
 
     def test_escape(self):
         self.validate_identity("""'"abc"'""")

diff --git a/tests/fixtures/identity.sql b/tests/fixtures/identity.sql
@@ -864,3 +864,4 @@ SELECT x FROM y ORDER BY x ASC
 KILL '123'
 KILL CONNECTION 123
 KILL QUERY '123'
+CHR(97)