schema.NewTable using regular golang *sql.DB

schema/schema.go

@@ -5,6 +5,7 @@
 package schema
 
 import (
+"database/sql"
 "fmt"
 "strings"
 
@@ -161,6 +162,25 @@ func IsTableExist(conn mysql.Executer, schema string, name string) (bool, error)
 return r.RowNumber() == 1, nil
 }
 
+func NewTableFromSqlDB(conn *sql.DB, schema string, name string) (*Table, error) {
+ta := &Table{
+Schema: schema,
+Name: name,
+Columns: make([]TableColumn, 0, 16),
+Indexes: make([]*Index, 0, 8),
+}
+
+if err := ta.fetchColumnsViaSqlDB(conn); err != nil {
+return nil, errors.Trace(err)
+}
+
+if err := ta.fetchIndexesViaSqlDB(conn); err != nil {
+return nil, errors.Trace(err)
+}
+
+return ta, nil
+}
+
 func NewTable(conn mysql.Executer, schema string, name string) (*Table, error) {
 ta := &Table{
 Schema: schema,
@@ -197,6 +217,30 @@ func (ta *Table) fetchColumns(conn mysql.Executer) error {
 return nil
 }
 
+func (ta *Table) fetchColumnsViaSqlDB(conn *sql.DB) error {
+r, err := conn.Query(fmt.Sprintf("describe `%s`.`%s`", ta.Schema, ta.Name))
+if err != nil {
+return errors.Trace(err)
+}
+
+defer r.Close()
+
+var unusedVal interface{}
+unused := &unusedVal
+
+for r.Next() {
+var name, colType, extra string
+err := r.Scan(&name, &colType, &unused, &unused, &unused, &extra)
+if err != nil {
+return errors.Trace(err)
+}
+
+ta.AddColumn(name, colType, extra)
+}
+
+return r.Err()
+}
+
 func (ta *Table) fetchIndexes(conn mysql.Executer) error {
 r, err := conn.Execute(fmt.Sprintf("show index from `%s`.`%s`", ta.Schema, ta.Name))
 if err != nil {
@@ -216,6 +260,59 @@ func (ta *Table) fetchIndexes(conn mysql.Executer) error {
 currentIndex.AddColumn(colName, cardinality)
 }
 
+return ta.fetchPrimaryKeyColumns()
+
+}
+
+func (ta *Table) fetchIndexesViaSqlDB(conn *sql.DB) error {
+r, err := conn.Query(fmt.Sprintf("show index from `%s`.`%s`", ta.Schema, ta.Name))
+if err != nil {
+return errors.Trace(err)
+}
+
+defer r.Close()
+
+var currentIndex *Index
+currentName := ""
+
+var unusedVal interface{}
+unused := &unusedVal
+
+for r.Next() {
+var indexName, colName string
+var cardinality uint64
+
+err := r.Scan(
+&unused,
+&unused,
+&indexName,
+&unused,
+&colName,
+&unused,
+&cardinality,
+&unused,
+&unused,
+&unused,
+&unused,
+&unused,
+&unused,
+)
+if err != nil {
+return errors.Trace(err)
+}
+
+if currentName != indexName {
+currentIndex = ta.AddIndex(indexName)
+currentName = indexName
+}
+
+currentIndex.AddColumn(colName, cardinality)
+}
+
+return ta.fetchPrimaryKeyColumns()
+}
+
+func (ta *Table) fetchPrimaryKeyColumns() error {
 if len(ta.Indexes) == 0 {
 return nil
 }

schema/schema_test.go

@@ -1,12 +1,14 @@
 package schema
 
 import (
+"database/sql"
 "flag"
 "fmt"
 "testing"
 
 . "github.com/pingcap/check"
 "github.com/siddontang/go-mysql/client"
+_ "github.com/siddontang/go-mysql/driver"
 )
 
 // use docker mysql for test
@@ -17,7 +19,8 @@ func Test(t *testing.T) {
 }
 
 type schemaTestSuite struct {
-conn *client.Conn
+conn *client.Conn
+sqlDB *sql.DB
 }
 
 var _ = Suite(&schemaTestSuite{})
@@ -26,12 +29,19 @@ func (s *schemaTestSuite) SetUpSuite(c *C) {
 var err error
 s.conn, err = client.Connect(fmt.Sprintf("%s:%d", *host, 3306), "root", "", "test")
 c.Assert(err, IsNil)
+
+s.sqlDB, err = sql.Open("mysql", fmt.Sprintf("root:@%s:3306", *host))
+c.Assert(err, IsNil)
 }
 
 func (s *schemaTestSuite) TearDownSuite(c *C) {
 if s.conn != nil {
 s.conn.Close()
 }
+
+if s.sqlDB != nil {
+s.sqlDB.Close()
+}
 }
 
 func (s *schemaTestSuite) TestSchema(c *C) {
@@ -74,6 +84,11 @@ func (s *schemaTestSuite) TestSchema(c *C) {
 c.Assert(ta.Columns[0].IsUnsigned, IsFalse)
 c.Assert(ta.Columns[8].IsUnsigned, IsTrue)
 c.Assert(ta.Columns[9].IsUnsigned, IsTrue)
+
+taSqlDb, err := NewTableFromSqlDB(s.sqlDB, "test", "schema_test")
+c.Assert(err, IsNil)
+
+c.Assert(taSqlDb, DeepEquals, ta)
 }
 
 func (s *schemaTestSuite) TestQuoteSchema(c *C) {