feat: Shopspring decimal support (#287)

* Queries and parameters tests.

* OUT parameter tests.

* Bug fix.

* TVP test.

* Bug fix.

* Another TVP test.

* Another TVP test.

* Another TVP test.

* Bug fix.

* Bug fix.

* Another TVP test.

* Bulk copy test.

* Bug fix.

* Bug fix.

* Another bulk copy test.

* Bug fix.

* Some MONEY type tests.

* Support MONEY type.

* Support Decimal type.

* Support NULL for MONEY type.

* Bug fix and more tests.

* MONEY encoding test.

* Bug fix.

* Query MONEY encoding test.

* Bug fix.

* Query MONEY encoding tests.

* DECIMAL encoding tests.

* Bug fix.

* Bulk copy money tests.

* Bug fix.

* Money bulkcopy support.

* Bug fix.

* SMALLMONEY bulkcopy support.

* Bug fix.

* Bug fix.

* Refactoring - generalize Money type wrapper.

* Bug fix.

* TVP MONEY test.

* TVP MONEY test.

* TVP MONEY test.

* TVP MONEY test.

* Remove redundant file.

* Simplify money encoding.

* Money test.

* More money tests.

* Remove redundant file.

* Update README.

* Money / bulk tests - error cases.

Author: El-76

README.md

@@ -438,6 +438,8 @@ are supported:
 * "github.com/golang-sql/civil".DateTime -> datetime2
 * "github.com/golang-sql/civil".Time -> time
 * mssql.TVP -> Table Value Parameter (TDS version dependent)
+* "github.com/shopspring/decimal".Decimal -> decimal
+* mssql.Money -> money
 
 Using an `int` parameter will send a 4 byte value (int) from a 32bit app and an 8 byte value (bigint) from a 64bit app. 
 To make sure your integer parameter matches the size of the SQL parameter, use the appropriate sized type like `int32` or `int8`.

bulkcopy.go

@@ -14,6 +14,7 @@ import (
 
 	"github.com/microsoft/go-mssqldb/internal/decimal"
 	"github.com/microsoft/go-mssqldb/msdsn"
+	shopspring "github.com/shopspring/decimal"
 )
 
 type Bulk struct {
@@ -346,6 +347,10 @@ func (b *Bulk) makeParam(val DataValue, col columnStruct) (res param, err error)
 	loc := getTimezone(b.cn)
 
 	switch valuer := val.(type) {
+	case Money[shopspring.Decimal]:
+		return b.makeParam(valuer.Decimal, col)
+	case Money[shopspring.NullDecimal]:
+		return b.makeParam(valuer.Decimal, col)
 	case driver.Valuer:
 		var e error
 		val, e = driver.DefaultParameterConverter.ConvertValue(valuer)
@@ -561,7 +566,37 @@ func (b *Bulk) makeParam(val DataValue, col columnStruct) (res param, err error)
 			err = fmt.Errorf("mssql: invalid type for time column: %T %s", val, val)
 			return
 		}
-	// case typeMoney, typeMoney4, typeMoneyN:
+	case typeMoney, typeMoney4, typeMoneyN:
+		switch v := val.(type) {
+		case string:
+			money, err := decimal.StringToDecimalScale(v, 4)
+			if err != nil {
+				return res, err
+			}
+
+			buf := make([]byte, col.ti.Size)
+
+			integer0 := money.GetInteger(0)
+			if col.ti.Size == 4 {
+				if money.IsPositive() {
+					binary.LittleEndian.PutUint32(buf, integer0)
+				} else {
+					binary.LittleEndian.PutUint32(buf, ^integer0+1)
+				}
+			} else {
+				integer := (uint64(money.GetInteger(1)) << 32) | uint64(integer0)
+				if !money.IsPositive() {
+					integer = ^integer + 1
+				}
+
+				binary.LittleEndian.PutUint32(buf, uint32(integer>>32))
+				binary.LittleEndian.PutUint32(buf[4:], uint32(integer))
+			}
+
+			res.buffer = buf
+		default:
+			return res, fmt.Errorf("unknown value for money: %T %#v", v, v)
+		}
 	case typeDecimal, typeDecimalN, typeNumeric, typeNumericN:
 		prec := col.ti.Prec
 		scale := col.ti.Scale

bulkcopy_test.go

@@ -13,6 +13,7 @@ import (
 	"testing"
 	"time"
 
+	"github.com/shopspring/decimal"
 	"github.com/stretchr/testify/assert"
 )
 
@@ -29,6 +30,8 @@ func TestBulkcopyWithInvalidNullableType(t *testing.T) {
 		"test_nullint16",
 		"test_nulltime",
 		"test_nulluniqueidentifier",
+		"test_nulldecimal",
+		"test_nullmoney",
 	}
 	values := []interface{}{
 		sql.NullFloat64{Valid: false},
@@ -40,6 +43,8 @@ func TestBulkcopyWithInvalidNullableType(t *testing.T) {
 		sql.NullInt16{Valid: false},
 		sql.NullTime{Valid: false},
 		NullUniqueIdentifier{Valid: false},
+		decimal.NullDecimal{Valid: false},
+		Money[decimal.NullDecimal]{decimal.NullDecimal{Valid: false}},
 	}
 
 	pool, logger := open(t)
@@ -176,9 +181,11 @@ func testBulkcopy(t *testing.T, guidConversion bool) {
 		{"test_nullint32", sql.NullInt32{2147483647, true}, 2147483647},
 		{"test_nullint16", sql.NullInt16{32767, true}, 32767},
 		{"test_nulltime", sql.NullTime{time.Date(2010, 11, 12, 13, 14, 15, 120000000, time.UTC), true}, time.Date(2010, 11, 12, 13, 14, 15, 120000000, time.UTC)},
+		{"test_nulldecimal", decimal.NewNullDecimal(decimal.New(1232355, -4)), decimal.New(1232355, -4)},
+		{"test_nullmoney", Money[decimal.NullDecimal]{decimal.NewNullDecimal(decimal.New(-21232311232355, -4))}, decimal.New(-21232311232355, -4)},
 		{"test_datetimen_midnight", time.Date(2025, 1, 1, 23, 59, 59, 998_350_000, time.UTC), time.Date(2025, 1, 2, 0, 0, 0, 0, time.UTC)},
-		// {"test_smallmoney", 1234.56, nil},
-		// {"test_money", 1234.56, nil},
+		{"test_smallmoney", Money[decimal.Decimal]{decimal.New(-32856, -4)}, decimal.New(-32856, -4)},
+		{"test_money", Money[decimal.Decimal]{decimal.New(-21232311232355, -4)}, decimal.New(-21232311232355, -4)},
 		{"test_decimal_18_0", 1234.0001, "1234"},
 		{"test_decimal_9_2", -1234.560001, "-1234.56"},
 		{"test_decimal_20_0", 1234, "1234"},
@@ -334,6 +341,20 @@ func compareValue(a interface{}, expected interface{}) bool {
 			return expected.Equal(got) && ez == az
 		}
 		return false
+	case decimal.Decimal:
+		actual, err := decimal.NewFromString(a.(string))
+		if err != nil {
+			return false
+		}
+
+		return expected.Equal(actual)
+	case Money[decimal.Decimal]:
+		actual, err := decimal.NewFromString(a.(string))
+		if err != nil {
+			return false
+		}
+
+		return expected.Decimal.Equal(actual)
 	default:
 		return reflect.DeepEqual(expected, a)
 	}
@@ -351,6 +372,8 @@ func setupNullableTypeTable(ctx context.Context, t *testing.T, conn *sql.Conn, t
 	[test_nullint16] [smallint] NULL,
 	[test_nulltime] [datetime] NULL,
 	[test_nulluniqueidentifier] [uniqueidentifier] NULL,
+	[test_nulldecimal] [decimal](18, 4) NULL,
+	[test_nullmoney] [money] NULL,
  CONSTRAINT [PK_` + tableName + `_id] PRIMARY KEY CLUSTERED
 (
 	[id] ASC
@@ -438,6 +461,8 @@ func setupTable(ctx context.Context, t *testing.T, conn *sql.Conn, tableName str
 	[test_nullint32] [int] NULL,
 	[test_nullint16] [smallint] NULL,
 	[test_nulltime] [datetime] NULL,
+	[test_nulldecimal] [decimal](18, 4) NULL,
+	[test_nullmoney] [money] NULL,
 	[test_datetimen_midnight] [datetime] NULL,
  CONSTRAINT [PK_` + tableName + `_id] PRIMARY KEY CLUSTERED
 (

go.mod

@@ -33,6 +33,7 @@ require (
 	github.com/kylelemons/godebug v1.1.0 // indirect
 	github.com/pkg/browser v0.0.0-20240102092130-5ac0b6a4141c // indirect
 	github.com/pmezard/go-difflib v1.0.0 // indirect
+	github.com/shopspring/decimal v1.4.0 // indirect
 	golang.org/x/net v0.40.0 // indirect
 	gopkg.in/yaml.v3 v3.0.1 // indirect
 )

go.sum

@@ -64,6 +64,8 @@ github.com/redis/go-redis/v9 v9.8.0 h1:q3nRvjrlge/6UD7eTu/DSg2uYiU2mCL0G/uzBWqhi
 github.com/redis/go-redis/v9 v9.8.0/go.mod h1:huWgSWd8mW6+m0VPhJjSSQ+d6Nh1VICQ6Q5lHuCH/Iw=
 github.com/rogpeppe/go-internal v1.12.0 h1:exVL4IDcn6na9z1rAb56Vxr+CgyK3nn3O+epU5NdKM8=
 github.com/rogpeppe/go-internal v1.12.0/go.mod h1:E+RYuTGaKKdloAfM02xzb0FW3Paa99yedzYV+kq4uf4=
+github.com/shopspring/decimal v1.4.0 h1:bxl37RwXBklmTi0C79JfXCEBD1cqqHt0bbgBAGFp81k=
+github.com/shopspring/decimal v1.4.0/go.mod h1:gawqmDU56v4yIKSwfBSFip1HdCCXN8/+DMd9qYNcwME=
 github.com/stretchr/objx v0.1.0/go.mod h1:HFkY916IF+rwdDfMAkV7OtwuqBVzrE8GR6GFx+wExME=
 github.com/stretchr/objx v0.4.0/go.mod h1:YvHI0jy2hoMjB+UWwv71VJQ9isScKT/TqJzVSSt89Yw=
 github.com/stretchr/objx v0.5.0/go.mod h1:Yh+to48EsGEfYuaHDzXPcE3xhTkx73EhmCGUpEOglKo=

internal/decimal/decimal.go

@@ -36,6 +36,11 @@ func init() {
 
 const autoScale = 100
 
+// GetInteger gets the ind'th element of the integer array
+func (d *Decimal) GetInteger(ind uint8) uint32 {
+	return d.integer[ind]
+}
+
 // SetInteger sets the ind'th element in the integer array
 func (d *Decimal) SetInteger(integer uint32, ind uint8) {
 	d.integer[ind] = integer

money.go

@@ -0,0 +1,24 @@
+package mssql
+
+import (
+	"database/sql"
+	"database/sql/driver"
+
+	"github.com/shopspring/decimal"
+)
+
+type Money[D decimal.Decimal|decimal.NullDecimal] struct {
+	Decimal D
+}
+
+func (m Money[D]) Value() (driver.Value, error) {
+	valuer, _ := any(m.Decimal).(driver.Valuer)
+
+	return valuer.Value()
+}
+
+func (m *Money[D]) Scan(v any) error {
+	scanner, _ := any(&m.Decimal).(sql.Scanner)
+
+	return scanner.Scan(v);
+}