From aeb5e5d885adfb4a4caf3dc2008c03d46a8da8de Mon Sep 17 00:00:00 2001
From: Esdras Beleza <esdras@esdrasbeleza.com>
Date: Tue, 16 Apr 2024 10:32:37 +0100
Subject: [PATCH] Fix Spark parameter creation when passing a `nil`-value named
 parameter to a query  (#199)

- When a `sql.NamedValue` has the field `Value` set to `nil`, the
resulting `cli_service.TSparkParameter` will also have the value `nil`
instead of `*cli_service.TSparkParameterValue{StringValue:
*"%!s(<nil>"}`.
- Add the type `SqlVoid`, following the conventions used in the [NodeJS
connector](https://github.com/databricks/databricks-sql-nodejs/blob/main/lib/DBSQLParameter.ts#L43-L51)
and the [Python
driver](https://github.com/databricks/databricks-sql-python/blob/f6fd7a7956a4dbc78ad36b5e079fe8d74176a0f1/src/databricks/sql/parameters/native.py#L319-L323).

Fix #193.

---------

Signed-off-by: Esdras Beleza <esdras@esdrasbeleza.com>
Signed-off-by: Levko Kravets <levko.ne@gmail.com>
Signed-off-by: candiduslynx <candiduslynx@gmail.com>
Co-authored-by: Levko Kravets <levko.ne@gmail.com>
Co-authored-by: Mahdi Dibaiee <mdibaiee@pm.me>
Co-authored-by: Alex Shcherbakov <candiduslynx@users.noreply.github.com>
---
 CHANGELOG.md      |  3 ++-
 parameter_test.go |  7 +++++--
 parameters.go     | 19 ++++++++++++++++---
 3 files changed, 23 insertions(+), 6 deletions(-)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index b899222..48e7db5 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,6 +1,7 @@
 # Release History
 
-- Fix formatting of *float64 parameters
+- Bug fix for issue 193: convertNamedValuesToSparkParams was incorrectly creating a Spark parameter value as "%!s(<nil>)" when a named param was nil (databricks/databricks-sql-go#199 by @esdrasbeleza)
+- Fix formatting of *float64 parameters (databricks/databricks-sql-go#215 by @esdrasbeleza)
 
 ## v1.5.4 (2024-04-10)
 
diff --git a/parameter_test.go b/parameter_test.go
index 3d4b10b..2c994cf 100644
--- a/parameter_test.go
+++ b/parameter_test.go
@@ -12,12 +12,13 @@ import (
 
 func TestParameter_Inference(t *testing.T) {
 	t.Run("Should infer types correctly", func(t *testing.T) {
-		values := [6]driver.NamedValue{
+		values := [7]driver.NamedValue{
 			{Name: "", Value: float32(5.1)},
 			{Name: "", Value: time.Now()},
 			{Name: "", Value: int64(5)},
 			{Name: "", Value: true},
 			{Name: "", Value: Parameter{Value: "6.2", Type: SqlDecimal}},
+			{Name: "", Value: nil},
 			{Name: "", Value: Parameter{Value: float64Ptr(6.2), Type: SqlUnkown}},
 		}
 		parameters := convertNamedValuesToSparkParams(values[:])
@@ -28,7 +29,9 @@ func TestParameter_Inference(t *testing.T) {
 		assert.Equal(t, string("true"), *parameters[3].Value.StringValue)
 		assert.Equal(t, string("DECIMAL(2,1)"), *parameters[4].Type)
 		assert.Equal(t, string("6.2"), *parameters[4].Value.StringValue)
-		assert.Equal(t, &cli_service.TSparkParameterValue{StringValue: strPtr("6.2")}, parameters[5].Value)
+		assert.Equal(t, string("VOID"), *parameters[5].Type)
+		assert.Nil(t, parameters[5].Value)
+		assert.Equal(t, &cli_service.TSparkParameterValue{StringValue: strPtr("6.2")}, parameters[6].Value)
 	})
 }
 func TestParameters_Names(t *testing.T) {
diff --git a/parameters.go b/parameters.go
index 7b780f4..0652d80 100644
--- a/parameters.go
+++ b/parameters.go
@@ -34,6 +34,7 @@ const (
 	SqlBoolean
 	SqlIntervalMonth
 	SqlIntervalDay
+	SqlVoid
 )
 
 func (s SqlType) String() string {
@@ -64,6 +65,8 @@ func (s SqlType) String() string {
 		return "INTERVAL MONTH"
 	case SqlIntervalDay:
 		return "INTERVAL DAY"
+	case SqlVoid:
+		return "VOID"
 	}
 	return "unknown"
 }
@@ -149,6 +152,9 @@ func inferType(param *Parameter) {
 	case time.Time:
 		param.Value = value.Format(time.RFC3339Nano)
 		param.Type = SqlTimestamp
+	case nil:
+		param.Value = nil
+		param.Type = SqlVoid
 	default:
 		s := fmt.Sprintf("%s", param.Value)
 		param.Value = s
@@ -163,14 +169,21 @@ func convertNamedValuesToSparkParams(values []driver.NamedValue) []*cli_service.
 	inferTypes(sqlParams)
 	for i := range sqlParams {
 		sqlParam := sqlParams[i]
-		sparkParamValue := sqlParam.Value.(string)
+		sparkValue := new(cli_service.TSparkParameterValue)
+		if sqlParam.Type == SqlVoid {
+			sparkValue = nil
+		} else {
+			stringValue := sqlParam.Value.(string)
+			sparkValue = &cli_service.TSparkParameterValue{StringValue: &stringValue}
+		}
+
 		var sparkParamType string
 		if sqlParam.Type == SqlDecimal {
-			sparkParamType = inferDecimalType(sparkParamValue)
+			sparkParamType = inferDecimalType(sparkValue.GetStringValue())
 		} else {
 			sparkParamType = sqlParam.Type.String()
 		}
-		sparkParam := cli_service.TSparkParameter{Name: &sqlParam.Name, Type: &sparkParamType, Value: &cli_service.TSparkParameterValue{StringValue: &sparkParamValue}}
+		sparkParam := cli_service.TSparkParameter{Name: &sqlParam.Name, Type: &sparkParamType, Value: sparkValue}
 		sparkParams = append(sparkParams, &sparkParam)
 	}
 	return sparkParams