addedd support for sql.Null types

bindings_test.go

@@ -861,3 +861,42 @@ func TestBulkArrayMultiPartBindingWithNull(t *testing.T) {
 		dbt.mustExec("DROP TABLE binding_test")
 	})
 }
+
+func TestFunctionNullSelect(t *testing.T) {
+	runTests(t, dsn, func(dbt *DBTest) {
+		dbt.mustExec(`
+		CREATE OR REPLACE FUNCTION NULLPARAMFUNCTION("param1" text, "param2" number, "param3" double)
+		RETURNS TABLE ("res1" text, "res2" number, "res3" double)
+		LANGUAGE SQL
+		AS 'select param1, param2, param3';
+		`)
+		if rows, err := dbt.db.Query("select * from table(NULLPARAMFUNCTION(?, ?, ?))", sql.NullString{}, sql.NullInt64{}, sql.NullFloat64{}); err != nil {
+			t.Fatal(err)
+		} else {
+			if rows.Err() != nil {
+				t.Fatal(err)
+			} else {
+				if !rows.Next() {
+					t.Fatal()
+				} else {
+					var r1 sql.NullString
+					var r2 sql.NullInt64
+					var r3 sql.NullFloat64
+					err = rows.Scan(&r1, &r2, &r3)
+					if err != nil {
+						t.Fatal(err)
+					}
+					if r1.Valid {
+						t.Fatal(err)
+					}
+					if r2.Valid {
+						t.Fatal(err)
+					}
+					if r3.Valid {
+						t.Fatal(err)
+					}
+				}
+			}
+		}
+	})
+}

connection.go

@@ -15,6 +15,7 @@ import (
 	"net/http"
 	"net/url"
 	"os"
+	"reflect"
 	"regexp"
 	"strconv"
 	"strings"
@@ -398,6 +399,11 @@ func (sc *snowflakeConn) Ping(ctx context.Context) error {
 // CheckNamedValue determines which types are handled by this driver aside from
 // the instances captured by driver.Value
 func (sc *snowflakeConn) CheckNamedValue(nv *driver.NamedValue) error {
+	switch reflect.TypeOf(nv.Value) {
+	case reflect.TypeOf(sql.NullString{}), reflect.TypeOf(sql.NullInt64{}),
+		reflect.TypeOf(sql.NullBool{}), reflect.TypeOf(sql.NullFloat64{}):
+		return nil
+	}
 	if supported := supportedArrayBind(nv); !supported {
 		return driver.ErrSkip
 	}

converter.go

@@ -4,6 +4,7 @@ package gosnowflake
 
 import (
 	"context"
+	"database/sql"
 	"database/sql/driver"
 	"encoding/hex"
 	"fmt"
@@ -58,13 +59,13 @@ func isInterfaceArrayBinding(t interface{}) bool {
 // goTypeToSnowflake translates Go data type to Snowflake data type.
 func goTypeToSnowflake(v driver.Value, tsmode snowflakeType) snowflakeType {
 	switch t := v.(type) {
-	case int64:
+	case int64, sql.NullInt64:
 		return fixedType
-	case float64:
+	case float64, sql.NullFloat64:
 		return realType
-	case bool:
+	case bool, sql.NullBool:
 		return booleanType
-	case string:
+	case string, sql.NullString:
 		return textType
 	case []byte:
 		if tsmode == binaryType {
@@ -171,6 +172,33 @@ func valueToString(v driver.Value, tsmode snowflakeType) (*string, error) {
 				return &s, nil
 			}
 		}
+		if ns, ok := v.(sql.NullString); ok {
+			if !ns.Valid {
+				return nil, nil
+			}
+			return &ns.String, nil
+		}
+		if ns, ok := v.(sql.NullInt64); ok {
+			if !ns.Valid {
+				return nil, nil
+			}
+			s := strconv.FormatInt(ns.Int64, 10)
+			return &s, nil
+		}
+		if ns, ok := v.(sql.NullFloat64); ok {
+			if !ns.Valid {
+				return nil, nil
+			}
+			s := strconv.FormatFloat(ns.Float64, 'g', -1, 32)
+			return &s, nil
+		}
+		if ns, ok := v.(sql.NullBool); ok {
+			if !ns.Valid {
+				return nil, nil
+			}
+			s := strconv.FormatBool(ns.Bool)
+			return &s, nil
+		}
 	}
 	return nil, fmt.Errorf("unsupported type: %v", v1.Kind())
 }