Dep upgrade mysql lib (#4161)

*  update gopkg file to add sql dep

vendor/github.com/go-sql-driver/mysql/rows.go

@@ -11,19 +11,20 @@ package mysql
 import (
 	"database/sql/driver"
 	"io"
+	"math"
+	"reflect"
 )
 
-type mysqlField struct {
-	tableName string
-	name      string
-	flags     fieldFlag
-	fieldType byte
-	decimals  byte
+type resultSet struct {
+	columns     []mysqlField
+	columnNames []string
+	done        bool
 }
 
 type mysqlRows struct {
-	mc      *mysqlConn
-	columns []mysqlField
+	mc     *mysqlConn
+	rs     resultSet
+	finish func()
 }
 
 type binaryRows struct {
@@ -34,37 +35,86 @@ type textRows struct {
 	mysqlRows
 }
 
-type emptyRows struct{}
-
 func (rows *mysqlRows) Columns() []string {
-	columns := make([]string, len(rows.columns))
+	if rows.rs.columnNames != nil {
+		return rows.rs.columnNames
+	}
+
+	columns := make([]string, len(rows.rs.columns))
 	if rows.mc != nil && rows.mc.cfg.ColumnsWithAlias {
 		for i := range columns {
-			if tableName := rows.columns[i].tableName; len(tableName) > 0 {
-				columns[i] = tableName + "." + rows.columns[i].name
+			if tableName := rows.rs.columns[i].tableName; len(tableName) > 0 {
+				columns[i] = tableName + "." + rows.rs.columns[i].name
 			} else {
-				columns[i] = rows.columns[i].name
+				columns[i] = rows.rs.columns[i].name
 			}
 		}
 	} else {
 		for i := range columns {
-			columns[i] = rows.columns[i].name
+			columns[i] = rows.rs.columns[i].name
 		}
 	}
+
+	rows.rs.columnNames = columns
 	return columns
 }
 
-func (rows *mysqlRows) Close() error {
+func (rows *mysqlRows) ColumnTypeDatabaseTypeName(i int) string {
+	return rows.rs.columns[i].typeDatabaseName()
+}
+
+// func (rows *mysqlRows) ColumnTypeLength(i int) (length int64, ok bool) {
+// 	return int64(rows.rs.columns[i].length), true
+// }
+
+func (rows *mysqlRows) ColumnTypeNullable(i int) (nullable, ok bool) {
+	return rows.rs.columns[i].flags&flagNotNULL == 0, true
+}
+
+func (rows *mysqlRows) ColumnTypePrecisionScale(i int) (int64, int64, bool) {
+	column := rows.rs.columns[i]
+	decimals := int64(column.decimals)
+
+	switch column.fieldType {
+	case fieldTypeDecimal, fieldTypeNewDecimal:
+		if decimals > 0 {
+			return int64(column.length) - 2, decimals, true
+		}
+		return int64(column.length) - 1, decimals, true
+	case fieldTypeTimestamp, fieldTypeDateTime, fieldTypeTime:
+		return decimals, decimals, true
+	case fieldTypeFloat, fieldTypeDouble:
+		if decimals == 0x1f {
+			return math.MaxInt64, math.MaxInt64, true
+		}
+		return math.MaxInt64, decimals, true
+	}
+
+	return 0, 0, false
+}
+
+func (rows *mysqlRows) ColumnTypeScanType(i int) reflect.Type {
+	return rows.rs.columns[i].scanType()
+}
+
+func (rows *mysqlRows) Close() (err error) {
+	if f := rows.finish; f != nil {
+		f()
+		rows.finish = nil
+	}
+
 	mc := rows.mc
 	if mc == nil {
 		return nil
 	}
-	if mc.netConn == nil {
-		return ErrInvalidConn
+	if err := mc.error(); err != nil {
+		return err
 	}
 
 	// Remove unread packets from stream
-	err := mc.readUntilEOF()
+	if !rows.rs.done {
+		err = mc.readUntilEOF()
+	}
 	if err == nil {
 		if err = mc.discardResults(); err != nil {
 			return err
@@ -75,10 +125,66 @@ func (rows *mysqlRows) Close() error {
 	return err
 }
 
+func (rows *mysqlRows) HasNextResultSet() (b bool) {
+	if rows.mc == nil {
+		return false
+	}
+	return rows.mc.status&statusMoreResultsExists != 0
+}
+
+func (rows *mysqlRows) nextResultSet() (int, error) {
+	if rows.mc == nil {
+		return 0, io.EOF
+	}
+	if err := rows.mc.error(); err != nil {
+		return 0, err
+	}
+
+	// Remove unread packets from stream
+	if !rows.rs.done {
+		if err := rows.mc.readUntilEOF(); err != nil {
+			return 0, err
+		}
+		rows.rs.done = true
+	}
+
+	if !rows.HasNextResultSet() {
+		rows.mc = nil
+		return 0, io.EOF
+	}
+	rows.rs = resultSet{}
+	return rows.mc.readResultSetHeaderPacket()
+}
+
+func (rows *mysqlRows) nextNotEmptyResultSet() (int, error) {
+	for {
+		resLen, err := rows.nextResultSet()
+		if err != nil {
+			return 0, err
+		}
+
+		if resLen > 0 {
+			return resLen, nil
+		}
+
+		rows.rs.done = true
+	}
+}
+
+func (rows *binaryRows) NextResultSet() error {
+	resLen, err := rows.nextNotEmptyResultSet()
+	if err != nil {
+		return err
+	}
+
+	rows.rs.columns, err = rows.mc.readColumns(resLen)
+	return err
+}
+
 func (rows *binaryRows) Next(dest []driver.Value) error {
 	if mc := rows.mc; mc != nil {
-		if mc.netConn == nil {
-			return ErrInvalidConn
+		if err := mc.error(); err != nil {
+			return err
 		}
 
 		// Fetch next row from stream
@@ -87,10 +193,20 @@ func (rows *binaryRows) Next(dest []driver.Value) error {
 	return io.EOF
 }
 
+func (rows *textRows) NextResultSet() (err error) {
+	resLen, err := rows.nextNotEmptyResultSet()
+	if err != nil {
+		return err
+	}
+
+	rows.rs.columns, err = rows.mc.readColumns(resLen)
+	return err
+}
+
 func (rows *textRows) Next(dest []driver.Value) error {
 	if mc := rows.mc; mc != nil {
-		if mc.netConn == nil {
-			return ErrInvalidConn
+		if err := mc.error(); err != nil {
+			return err
 		}
 
 		// Fetch next row from stream
@@ -98,15 +214,3 @@ func (rows *textRows) Next(dest []driver.Value) error {
 	}
 	return io.EOF
 }
-
-func (rows emptyRows) Columns() []string {
-	return nil
-}
-
-func (rows emptyRows) Close() error {
-	return nil
-}
-
-func (rows emptyRows) Next(dest []driver.Value) error {
-	return io.EOF
-}