Fix handling huge int numbers via PG numeric, close #38

scripts/test-data-types.sql

@@ -19,11 +19,12 @@ CREATE TABLE test_table (
   int2_column INT2,
   int4_column INT4,
   int8_column INT8,
+  hugeint_column NUMERIC(20, 0),
   xid_column XID,
   xid8_column XID8,
   float4_column FLOAT4,
   float8_column FLOAT8,
-  numeric_column NUMERIC(10, 2),
+  numeric_column NUMERIC(40, 2),
   date_column DATE,
   time_column TIME,
   time_ms_column TIME(3),
@@ -58,6 +59,7 @@ INSERT INTO test_table (
   int2_column,
   int4_column,
   int8_column,
+  hugeint_column,
   xid_column,
   xid8_column,
   float4_column,
@@ -95,6 +97,7 @@ INSERT INTO test_table (
   32767::INT2,                              -- int2_column
   2147483647::INT4,                         -- int4_column
   9223372036854775807::INT8,                -- int8_column
+  10000000000000000000,                     -- hugeint_column
   '4294967295'::XID,                        -- xid_column
   '18446744073709551615'::XID8,             -- xid8_column
   3.14::FLOAT4,                             -- float4_column
@@ -132,6 +135,7 @@ INSERT INTO test_table (
   -32767::INT2,                             -- int2_column
   NULL,                                     -- int4_column
   -9223372036854775807::INT8,               -- int8_column
+  NULL,                                     -- hugeint_column
   NULL,                                     -- xid_column
   NULL,                                     -- xid8_column
   'NaN',                                    -- float4_column

src/init_test.go

@@ -62,6 +62,14 @@ var TEST_PG_SCHEMA_COLUMNS = []PgSchemaColumn{
 		NumericScale:     "0",
 		Namespace:        "pg_catalog",
 	},
+	{
+		ColumnName:       "hugeint_column",
+		DataType:         "numeric",
+		UdtName:          "numeric",
+		NumericPrecision: "20", // Will be capped to 38
+		NumericScale:     "0",
+		Namespace:        "pg_catalog",
+	},
 	{
 		ColumnName: "xid_column",
 		DataType:   "xid",
@@ -263,6 +271,7 @@ var TEST_LOADED_ROWS = [][]string{
 		"32767",                                // int2_column
 		"2147483647",                           // int4_column
 		"9223372036854775807",                  // int8_column
+		"10000000000000000000",                 // hugeint_column
 		"4294967295",                           // xid_column
 		"18446744073709551615",                 // xid8_column
 		"3.14",                                 // float4_column
@@ -302,6 +311,7 @@ var TEST_LOADED_ROWS = [][]string{
 		"-32767",                           // int2_column
 		PG_NULL_STRING,                     // int4_column
 		"-9223372036854775807",             // int8_column
+		PG_NULL_STRING,                     // hugeint_column
 		PG_NULL_STRING,                     // xid_column
 		PG_NULL_STRING,                     // xid8_column
 		"NaN",                              // float4_column

src/query_handler.go

@@ -8,6 +8,7 @@ import (
 	"encoding/csv"
 	"errors"
 	"fmt"
+	"math/big"
 	"strconv"
 	"strings"
 
@@ -118,6 +119,31 @@ func (nullUint64 NullUint64) String() string {
 
 ////////////////////////////////////////////////////////////////////////////////////////////////////
 
+type NullBigInt struct {
+	Present bool
+	Value   *big.Int
+}
+
+func (nullBigInt *NullBigInt) Scan(value interface{}) error {
+	if value == nil {
+		nullBigInt.Present = false
+		return nil
+	}
+
+	nullBigInt.Present = true
+	nullBigInt.Value = value.(*big.Int)
+	return nil
+}
+
+func (nullBigInt NullBigInt) String() string {
+	if nullBigInt.Present {
+		return fmt.Sprintf("%v", nullBigInt.Value)
+	}
+	return ""
+}
+
+////////////////////////////////////////////////////////////////////////////////////////////////////
+
 type NullArray struct {
 	Present bool
 	Value   []interface{}
@@ -474,6 +500,10 @@ func (queryHandler *QueryHandler) columnTypeOid(col *sql.ColumnType) uint32 {
 		return pgtype.XID8OID
 	case "UBIGINT[]":
 		return pgtype.XID8ArrayOID
+	case "HUGEINT":
+		return pgtype.NumericOID
+	case "HUGEINT[]":
+		return pgtype.NumericArrayOID
 	case "FLOAT":
 		return pgtype.Float4OID
 	case "FLOAT[]":
@@ -540,7 +570,7 @@ func (queryHandler *QueryHandler) generateDataRow(rows *sql.Rows, cols []*sql.Co
 		case "int32":
 			var value sql.NullInt32
 			valuePtrs[i] = &value
-		case "int64", "*big.Int":
+		case "int64":
 			var value sql.NullInt64
 			valuePtrs[i] = &value
 		case "uint32": // xid
@@ -561,6 +591,9 @@ func (queryHandler *QueryHandler) generateDataRow(rows *sql.Rows, cols []*sql.Co
 		case "time.Time":
 			var value sql.NullTime
 			valuePtrs[i] = &value
+		case "*big.Int":
+			var value NullBigInt
+			valuePtrs[i] = &value
 		case "duckdb.Decimal":
 			var value NullDecimal
 			valuePtrs[i] = &value
@@ -643,6 +676,12 @@ func (queryHandler *QueryHandler) generateDataRow(rows *sql.Rows, cols []*sql.Co
 			} else {
 				values = append(values, nil)
 			}
+		case *NullBigInt:
+			if value.Present {
+				values = append(values, []byte(value.String()))
+			} else {
+				values = append(values, nil)
+			}
 		case *NullDecimal:
 			if value.Present {
 				values = append(values, []byte(value.String()))

src/query_handler_test.go

@@ -352,6 +352,16 @@ func TestHandleQuery(t *testing.T) {
 			"types":       {Uint32ToString(pgtype.Int8OID)},
 			"values":      {"-9223372036854775807"},
 		},
+		"SELECT hugeint_column FROM public.test_table WHERE hugeint_column IS NOT NULL": {
+			"description": {"hugeint_column"},
+			"types":       {Uint32ToString(pgtype.NumericOID)},
+			"values":      {"1e+19"},
+		},
+		"SELECT hugeint_column FROM public.test_table WHERE hugeint_column IS NULL": {
+			"description": {"hugeint_column"},
+			"types":       {Uint32ToString(pgtype.NumericOID)},
+			"values":      {""},
+		},
 		"SELECT xid_column FROM public.test_table WHERE xid_column IS NOT NULL": {
 			"description": {"xid_column"},
 			"types":       {Uint32ToString(pgtype.XIDOID)},