diff --git a/field/result_field.go b/field/result_field.go
index 9e3803b01a..c6847bc3db 100644
--- a/field/result_field.go
+++ b/field/result_field.go
@@ -24,7 +24,6 @@ import (
 	"github.com/juju/errors"
 	"github.com/pingcap/tidb/column"
 	mysql "github.com/pingcap/tidb/mysqldef"
-	"github.com/pingcap/tidb/util/types"
 )
 
 const (
@@ -89,14 +88,6 @@ func ColToResultField(col *column.Col, tableName string) *ResultField {
 		TableName:    tableName,
 		OrgTableName: tableName,
 	}
-
-	if rf.Col.Flen == types.UnspecifiedLength {
-		rf.Col.Flen = 0
-	}
-	if rf.Col.Decimal == types.UnspecifiedLength {
-		rf.Col.Decimal = 0
-	}
-
 	// Keep things compatible for old clients.
 	// Refer to mysql-server/sql/protocol.cc send_result_set_metadata()
 	if rf.Tp == mysql.TypeVarchar {
diff --git a/mysqldef/util.go b/mysqldef/util.go
index da8c9c7927..11f08c03a3 100644
--- a/mysqldef/util.go
+++ b/mysqldef/util.go
@@ -17,6 +17,7 @@ package mysqldef
 // Call this when no Flen assigned in ddl.
 // or column value is calculated from an expression.
 // For example: "select count(*) from t;", the column type is int64 and Flen in ResultField will be 21.
+// See: https://dev.mysql.com/doc/refman/5.7/en/storage-requirements.html
 func GetDefaultFieldLength(tp byte) int {
 	switch tp {
 	case TypeTiny:
@@ -29,8 +30,25 @@ func GetDefaultFieldLength(tp byte) int {
 		return 11
 	case TypeLonglong:
 		return 21
+	case TypeDecimal:
+		// See: https://dev.mysql.com/doc/refman/5.7/en/fixed-point-types.html
+		return 10
+	case TypeBit, TypeBlob:
+		return -1
 	default:
 		//TODO: add more types
-		return 0
+		return -1
+	}
+}
+
+// GetDefaultDecimal returns the default decimal length for column.
+func GetDefaultDecimal(tp byte) int {
+	switch tp {
+	case TypeDecimal:
+		// See: https://dev.mysql.com/doc/refman/5.7/en/fixed-point-types.html
+		return 0
+	default:
+		//TODO: add more types
+		return -1
 	}
 }
diff --git a/mysqldef/util_test.go b/mysqldef/util_test.go
index 1baff0c452..e2e98a9f9d 100644
--- a/mysqldef/util_test.go
+++ b/mysqldef/util_test.go
@@ -25,7 +25,9 @@ func TestGetFieldLength(t *testing.T) {
 		{TypeInt24, 9},
 		{TypeLong, 11},
 		{TypeLonglong, 21},
-		{TypeNull, 0},
+		{TypeBit, -1},
+		{TypeBlob, -1},
+		{TypeNull, -1},
 	}
 
 	for _, test := range tbl {
diff --git a/parser/coldef/col_def.go b/parser/coldef/col_def.go
index 041afb6832..8010c08dec 100644
--- a/parser/coldef/col_def.go
+++ b/parser/coldef/col_def.go
@@ -181,9 +181,12 @@ func ColumnDefToCol(offset int, colDef *ColumnDef) (*column.Col, []*TableConstra
 	}
 
 	// If flen is not assigned, assigned it by type.
-	if col.Flen == 0 {
+	if col.Flen == types.UnspecifiedLength {
 		col.Flen = mysql.GetDefaultFieldLength(col.Tp)
 	}
+	if col.Decimal == types.UnspecifiedLength {
+		col.Decimal = mysql.GetDefaultDecimal(col.Tp)
+	}
 
 	setOnUpdateNow := false
 	hasDefaultValue := false
diff --git a/plan/plans/info.go b/plan/plans/info.go
index 2779dfbe1e..3a2b214314 100644
--- a/plan/plans/info.go
+++ b/plan/plans/info.go
@@ -361,8 +361,14 @@ func (isp *InfoSchemaPlan) fetchColumns(schemas []*model.DBInfo) {
 				if decimal == types.UnspecifiedLength {
 					decimal = 0
 				}
-				dataType := types.TypeToStr(col.Tp, col.Charset == charset.CharsetBin)
-				columnType := fmt.Sprintf("%s(%d)", dataType, colLen)
+				columnType := types.TypeToStr(col.Tp, col.Charset == charset.CharsetBin)
+				if col.Decimal == types.UnspecifiedLength {
+					if colLen != types.UnspecifiedLength {
+						columnType = fmt.Sprintf("%s(%d)", columnType, colLen)
+					}
+				} else {
+					columnType = fmt.Sprintf("%s(%d, %d)", columnType, colLen, col.Decimal)
+				}
 				columnDesc := column.NewColDesc(&column.Col{ColumnInfo: *col})
 				var columnDefault interface{}
 				if columnDesc.DefaultValue != nil {
diff --git a/tidb-server/server/conn.go b/tidb-server/server/conn.go
index 26f290b4bd..5f19f589fb 100644
--- a/tidb-server/server/conn.go
+++ b/tidb-server/server/conn.go
@@ -433,6 +433,7 @@ func (cc *clientConn) writeResultset(rs ResultSet, binary bool) error {
 			var rowData []byte
 			rowData, err = dumpRowValuesBinary(cc.alloc, columns, row)
 			if err != nil {
+				fmt.Println("[conn]", err)
 				return errors.Trace(err)
 			}
 			data = append(data, rowData...)
diff --git a/tidb-server/server/driver_tidb.go b/tidb-server/server/driver_tidb.go
index 1ea32908fa..f536ca92ec 100644
--- a/tidb-server/server/driver_tidb.go
+++ b/tidb-server/server/driver_tidb.go
@@ -272,8 +272,16 @@ func convertColumnInfo(fld *field.ResultField) (ci *ColumnInfo) {
 	ci.Schema = fld.DBName
 	ci.Flag = uint16(fld.Flag)
 	ci.Charset = uint16(mysql.CharsetIDs[fld.Charset])
-	ci.ColumnLength = uint32(fld.Flen)
-	ci.Decimal = uint8(fld.Decimal)
+	if fld.Flen == -1 {
+		ci.ColumnLength = 0
+	} else {
+		ci.ColumnLength = uint32(fld.Flen)
+	}
+	if fld.Decimal == -1 {
+		ci.Decimal = 0
+	} else {
+		ci.Decimal = uint8(fld.Decimal)
+	}
 	ci.Type = uint8(fld.Tp)
 	return
 }
diff --git a/tidb_test.go b/tidb_test.go
index b14b5fdbad..71e957420c 100644
--- a/tidb_test.go
+++ b/tidb_test.go
@@ -888,7 +888,7 @@ func (s *testSessionSuite) TestShow(c *C) {
 	rows, err := r.Rows(-1, 0)
 	c.Assert(err, IsNil)
 	c.Assert(rows, HasLen, 1)
-	match(c, rows[0], "c", "int", "YES", "", nil, "")
+	match(c, rows[0], "c", "int(11)", "YES", "", nil, "")
 
 	r = mustExecSQL(c, se, "show collation where Charset = 'utf8' and Collation = 'utf8_bin'")
 	row, err = r.FirstRow()
diff --git a/util/types/etc.go b/util/types/etc.go
index 7387e25515..b2e7cde4da 100644
--- a/util/types/etc.go
+++ b/util/types/etc.go
@@ -89,22 +89,22 @@ func TypeStr(tp byte) (r string) {
 func TypeToStr(tp byte, binary bool) string {
 	switch tp {
 	case mysql.TypeBlob:
-		if binary {
+		if !binary {
 			return "text"
 		}
 		return "blob"
 	case mysql.TypeLongBlob:
-		if binary {
+		if !binary {
 			return "longtext"
 		}
 		return "longblob"
 	case mysql.TypeTinyBlob:
-		if binary {
+		if !binary {
 			return "tinytext"
 		}
 		return "tinyblob"
 	case mysql.TypeMediumBlob:
-		if binary {
+		if !binary {
 			return "mediumtext"
 		}
 		return "mediumblob"
diff --git a/util/types/etc_test.go b/util/types/etc_test.go
index 6212535605..b1af52f00d 100644
--- a/util/types/etc_test.go
+++ b/util/types/etc_test.go
@@ -68,17 +68,17 @@ func (s *testTypeEtcSuite) TestTypeToStr(c *C) {
 	testTypeStr(c, mysql.TypeYear, "year")
 	testTypeStr(c, 0xdd, "")
 
-	testTypeToStr(c, mysql.TypeBlob, true, "text")
-	testTypeToStr(c, mysql.TypeLongBlob, true, "longtext")
-	testTypeToStr(c, mysql.TypeTinyBlob, true, "tinytext")
-	testTypeToStr(c, mysql.TypeMediumBlob, true, "mediumtext")
+	testTypeToStr(c, mysql.TypeBlob, false, "text")
+	testTypeToStr(c, mysql.TypeLongBlob, false, "longtext")
+	testTypeToStr(c, mysql.TypeTinyBlob, false, "tinytext")
+	testTypeToStr(c, mysql.TypeMediumBlob, false, "mediumtext")
 	testTypeToStr(c, mysql.TypeVarchar, true, "varbinary")
 	testTypeToStr(c, mysql.TypeString, true, "binary")
 	testTypeToStr(c, mysql.TypeTiny, true, "tinyint")
-	testTypeToStr(c, mysql.TypeBlob, false, "blob")
-	testTypeToStr(c, mysql.TypeLongBlob, false, "longblob")
-	testTypeToStr(c, mysql.TypeTinyBlob, false, "tinyblob")
-	testTypeToStr(c, mysql.TypeMediumBlob, false, "mediumblob")
+	testTypeToStr(c, mysql.TypeBlob, true, "blob")
+	testTypeToStr(c, mysql.TypeLongBlob, true, "longblob")
+	testTypeToStr(c, mysql.TypeTinyBlob, true, "tinyblob")
+	testTypeToStr(c, mysql.TypeMediumBlob, true, "mediumblob")
 	testTypeToStr(c, mysql.TypeVarchar, false, "varchar")
 	testTypeToStr(c, mysql.TypeString, false, "char")
 	testTypeToStr(c, mysql.TypeShort, true, "smallint")