Fix: Parametrized bigdecimal mapping was being concatenated with params

Author: themisvaltinos

sqlglot/generators/duckdb.py

@@ -663,6 +663,10 @@ def _datatype_sql(self: DuckDBGenerator, expression: exp.DataType) -> str:
     if expression.is_type(exp.DType.TIME, exp.DType.TIMETZ, exp.DType.TIMESTAMPTZ):
         return expression.this.value
 
+    # BIGDECIMAL type maps to DECIMAL(38, 5) but we should pass through user params when provided
+    if expression.is_type(exp.DType.BIGDECIMAL) and expression.expressions:
+        return f"DECIMAL({self.expressions(expression, flat=True)})"
+
     return self.datatype_sql(expression)
 
 

tests/dialects/test_bigquery.py

@@ -3824,6 +3824,14 @@ def test_bignumeric(self):
                     },
                 )
 
+                self.validate_all(
+                    f"DECLARE x {type_}(76, 38)",
+                    write={
+                        "bigquery": "DECLARE x BIGNUMERIC(76, 38)",
+                        "duckdb": "DECLARE x DECIMAL(76, 38)",
+                    },
+                )
+
                 self.validate_all(
                     f"SELECT CAST(1 AS {type_})",
                     write={