fix(snowflake): do not track the varchar length if it is maximum

Author: cpcloud

ibis/backends/snowflake/tests/test_datatypes.py

@@ -63,10 +63,10 @@ def con():
     ("DOUBLE PRECISION", dt.float64),
     ("REAL", dt.float64),
     ("VARCHAR", dt.string),
-    ("VARCHAR(50)", dt.string),
-    ("CHAR", dt.string),
-    ("CHAR(5)", dt.string),
-    ("CHARACTER", dt.string),
+    ("VARCHAR(50)", dt.String(length=50)),
+    ("CHAR", dt.String(length=1)),
+    ("CHAR(5)", dt.String(length=5)),
+    ("CHARACTER", dt.String(length=1)),
     ("STRING", dt.string),
     ("TEXT", dt.string),
     ("BINARY", dt.binary),

ibis/backends/sql/datatypes.py

@@ -781,6 +781,17 @@ class SnowflakeType(SqlglotType):
 
     default_temporal_scale = 9
 
+    @classmethod
+    def _from_sqlglot_VARCHAR(
+        cls, length: sge.DataTypeParam | None = None, nullable: bool | None = None
+    ) -> dt.String:
+        if length is not None and (bound := length.this.this).isdigit():
+            bound = int(bound)
+        else:
+            bound = None
+        # treat max length as no length specified
+        return dt.String(length=bound if bound != 1 << 24 else None, nullable=nullable)
+
     @classmethod
     def _from_sqlglot_FLOAT(cls, nullable: bool | None = None) -> dt.Float64:
         return dt.Float64(nullable=nullable)