return unsigned in database type name when necessary

AUTHORS

@@ -67,6 +67,7 @@ Linh Tran Tuan <linhduonggnu at gmail.com>
 Lion Yang <lion at aosc.xyz>
 Luca Looz <luca.looz92 at gmail.com>
 Lucas Liu <extrafliu at gmail.com>
+Lunny Xiao <xiaolunwen at gmail.com>
 Luke Scott <luke at webconnex.com>
 Maciej Zimnoch <maciej.zimnoch at codilime.com>
 Michael Woolnough <michael.woolnough at gmail.com>

README.md

@@ -454,7 +454,7 @@ user:password@/
 The connection pool is managed by Go's database/sql package. For details on how to configure the size of the pool and how long connections stay in the pool see `*DB.SetMaxOpenConns`, `*DB.SetMaxIdleConns`, and `*DB.SetConnMaxLifetime` in the [database/sql documentation](https://golang.org/pkg/database/sql/). The read, write, and dial timeouts for each individual connection are configured with the DSN parameters [`readTimeout`](#readtimeout), [`writeTimeout`](#writetimeout), and [`timeout`](#timeout), respectively.
 
 ## `ColumnType` Support
-This driver supports the [`ColumnType` interface](https://golang.org/pkg/database/sql/#ColumnType) introduced in Go 1.8, with the exception of [`ColumnType.Length()`](https://golang.org/pkg/database/sql/#ColumnType.Length), which is currently not supported.
+This driver supports the [`ColumnType` interface](https://golang.org/pkg/database/sql/#ColumnType) introduced in Go 1.8, with the exception of [`ColumnType.Length()`](https://golang.org/pkg/database/sql/#ColumnType.Length), which is currently not supported. All Unsigned database type names will be returned `UNSIGNED ` with `INT`, `TINYINT`, `SMALLINT`, `BIGINT`.
 
 ## `context.Context` Support
 Go 1.8 added `database/sql` support for `context.Context`. This driver supports query timeouts and cancellation via contexts.

driver_test.go

@@ -2808,10 +2808,10 @@ func TestRowsColumnTypes(t *testing.T) {
 		{"mediumintnull", "MEDIUMINT", "MEDIUMINT", scanTypeNullInt, true, 0, 0, [3]string{"0", "42", "NULL"}, [3]interface{}{ni0, ni42, niNULL}},
 		{"bigint", "BIGINT NOT NULL", "BIGINT", scanTypeInt64, false, 0, 0, [3]string{"0", "65535", "-42"}, [3]interface{}{int64(0), int64(65535), int64(-42)}},
 		{"bigintnull", "BIGINT", "BIGINT", scanTypeNullInt, true, 0, 0, [3]string{"NULL", "1", "42"}, [3]interface{}{niNULL, ni1, ni42}},
-		{"tinyuint", "TINYINT UNSIGNED NOT NULL", "TINYINT", scanTypeUint8, false, 0, 0, [3]string{"0", "255", "42"}, [3]interface{}{uint8(0), uint8(255), uint8(42)}},
-		{"smalluint", "SMALLINT UNSIGNED NOT NULL", "SMALLINT", scanTypeUint16, false, 0, 0, [3]string{"0", "65535", "42"}, [3]interface{}{uint16(0), uint16(65535), uint16(42)}},
-		{"biguint", "BIGINT UNSIGNED NOT NULL", "BIGINT", scanTypeUint64, false, 0, 0, [3]string{"0", "65535", "42"}, [3]interface{}{uint64(0), uint64(65535), uint64(42)}},
-		{"uint13", "INT(13) UNSIGNED NOT NULL", "INT", scanTypeUint32, false, 0, 0, [3]string{"0", "1337", "42"}, [3]interface{}{uint32(0), uint32(1337), uint32(42)}},
+		{"tinyuint", "TINYINT UNSIGNED NOT NULL", "UNSIGNED TINYINT", scanTypeUint8, false, 0, 0, [3]string{"0", "255", "42"}, [3]interface{}{uint8(0), uint8(255), uint8(42)}},
+		{"smalluint", "SMALLINT UNSIGNED NOT NULL", "UNSIGNED SMALLINT", scanTypeUint16, false, 0, 0, [3]string{"0", "65535", "42"}, [3]interface{}{uint16(0), uint16(65535), uint16(42)}},
+		{"biguint", "BIGINT UNSIGNED NOT NULL", "UNSIGNED BIGINT", scanTypeUint64, false, 0, 0, [3]string{"0", "65535", "42"}, [3]interface{}{uint64(0), uint64(65535), uint64(42)}},
+		{"uint13", "INT(13) UNSIGNED NOT NULL", "UNSIGNED INT", scanTypeUint32, false, 0, 0, [3]string{"0", "1337", "42"}, [3]interface{}{uint32(0), uint32(1337), uint32(42)}},
 		{"float", "FLOAT NOT NULL", "FLOAT", scanTypeFloat32, false, math.MaxInt64, math.MaxInt64, [3]string{"0", "42", "13.37"}, [3]interface{}{float32(0), float32(42), float32(13.37)}},
 		{"floatnull", "FLOAT", "FLOAT", scanTypeNullFloat, true, math.MaxInt64, math.MaxInt64, [3]string{"0", "NULL", "13.37"}, [3]interface{}{nf0, nfNULL, nf1337}},
 		{"float74null", "FLOAT(7,4)", "FLOAT", scanTypeNullFloat, true, math.MaxInt64, 4, [3]string{"0", "NULL", "13.37"}, [3]interface{}{nf0, nfNULL, nf1337}},

fields.go

@@ -41,13 +41,19 @@ func (mf *mysqlField) typeDatabaseName() string {
 	case fieldTypeJSON:
 		return "JSON"
 	case fieldTypeLong:
+		if mf.flags&flagUnsigned != 0 {
+			return "UNSIGNED INT"
+		}
 		return "INT"
 	case fieldTypeLongBLOB:
 		if mf.charSet != collations[binaryCollation] {
 			return "LONGTEXT"
 		}
 		return "LONGBLOB"
 	case fieldTypeLongLong:
+		if mf.flags&flagUnsigned != 0 {
+			return "UNSIGNED BIGINT"
+		}
 		return "BIGINT"
 	case fieldTypeMediumBLOB:
 		if mf.charSet != collations[binaryCollation] {
@@ -63,6 +69,9 @@ func (mf *mysqlField) typeDatabaseName() string {
 	case fieldTypeSet:
 		return "SET"
 	case fieldTypeShort:
+		if mf.flags&flagUnsigned != 0 {
+			return "UNSIGNED SMALLINT"
+		}
 		return "SMALLINT"
 	case fieldTypeString:
 		if mf.charSet == collations[binaryCollation] {
@@ -74,6 +83,9 @@ func (mf *mysqlField) typeDatabaseName() string {
 	case fieldTypeTimestamp:
 		return "TIMESTAMP"
 	case fieldTypeTiny:
+		if mf.flags&flagUnsigned != 0 {
+			return "UNSIGNED TINYINT"
+		}
 		return "TINYINT"
 	case fieldTypeTinyBLOB:
 		if mf.charSet != collations[binaryCollation] {