Update ql with latest transaction changes.

ql/collection.go

@@ -25,8 +25,8 @@ import (
 	"database/sql"
 
 	"upper.io/db.v2"
-	"upper.io/db.v2/sqlbuilder"
 	"upper.io/db.v2/internal/sqladapter"
+	"upper.io/db.v2/sqlbuilder"
 )
 
 // table is the actual implementation of a collection.
@@ -63,7 +63,7 @@ func (r *resultProxy) Select(fields ...interface{}) db.Result {
 			var columns []struct {
 				Name string `db:"Name"`
 			}
-			err := r.t.d.Builder.Select("Name").
+			err := r.t.d.Select("Name").
 				From("__Column").
 				Where("TableName", r.t.Name()).
 				Iterator().All(&columns)

ql/database.go

@@ -24,29 +24,23 @@ package ql
 import (
 	"database/sql"
 	"errors"
+	"sync"
 	"sync/atomic"
 
 	_ "github.com/cznic/ql/driver" // QL driver
 	"upper.io/db.v2"
+	"upper.io/db.v2/internal/sqladapter"
 	"upper.io/db.v2/sqlbuilder"
 	"upper.io/db.v2/sqlbuilder/exql"
-	"upper.io/db.v2/internal/sqladapter"
 )
 
-// Database represents a SQL database.
-type Database interface {
-	db.Database
-	builder.Builder
-
-	NewTransaction() (Tx, error)
-}
-
 // database is the actual implementation of Database
 type database struct {
 	sqladapter.BaseDatabase // Leveraged by sqladapter
-	builder.Builder
+	db.SQLBuilder
 
 	connURL db.ConnectionURL
+	txMu    sync.Mutex
 }
 
 var (
@@ -56,8 +50,7 @@ var (
 )
 
 var (
-	_ = sqladapter.Database(&database{})
-	_ = db.Database(&database{})
+	_ = db.SQLDatabase(&database{})
 )
 
 // newDatabase binds *database with sqladapter and the SQL builer.
@@ -69,7 +62,7 @@ func newDatabase(settings db.ConnectionURL) (*database, error) {
 }
 
 // Open stablishes a new connection to a SQL server.
-func Open(settings db.ConnectionURL) (Database, error) {
+func Open(settings db.ConnectionURL) (db.SQLDatabase, error) {
 	d, err := newDatabase(settings)
 	if err != nil {
 		return nil, err
@@ -93,7 +86,7 @@ func (d *database) ConnectionURL() db.ConnectionURL {
 	return d.connURL
 }
 
-// Open attempts to open a connection to the database server.
+// Open stablishes a new connection with the SQL server.
 func (d *database) Open(connURL db.ConnectionURL) error {
 	if connURL == nil {
 		return db.ErrMissingConnURL
@@ -102,18 +95,66 @@ func (d *database) Open(connURL db.ConnectionURL) error {
 	return d.open()
 }
 
-// NewTransaction starts a transaction block.
-func (d *database) NewTransaction() (Tx, error) {
+// NewTx returns a transaction session.
+func NewTx(sqlTx *sql.Tx) (db.SQLTx, error) {
+	d, err := newDatabase(nil)
+	if err != nil {
+		return nil, err
+	}
+
+	// Binding with sqladapter's logic.
+	d.BaseDatabase = sqladapter.NewBaseDatabase(d)
+
+	// Binding with builder.
+	b, err := builder.New(d.BaseDatabase, template)
+	if err != nil {
+		return nil, err
+	}
+	d.SQLBuilder = b
+
+	if err := d.BaseDatabase.BindTx(sqlTx); err != nil {
+		return nil, err
+	}
+
+	newTx := sqladapter.NewTx(d)
+	return &tx{DatabaseTx: newTx}, nil
+}
+
+// New wraps the given *sql.DB session and creates a new db session.
+func New(sess *sql.DB) (db.SQLDatabase, error) {
+	d, err := newDatabase(nil)
+	if err != nil {
+		return nil, err
+	}
+
+	// Binding with sqladapter's logic.
+	d.BaseDatabase = sqladapter.NewBaseDatabase(d)
+
+	// Binding with builder.
+	b, err := builder.New(d.BaseDatabase, template)
+	if err != nil {
+		return nil, err
+	}
+	d.SQLBuilder = b
+
+	if err := d.BaseDatabase.BindSession(sess); err != nil {
+		return nil, err
+	}
+	return d, nil
+}
+
+// NewTx starts a transaction block.
+func (d *database) NewTx() (db.SQLTx, error) {
 	nTx, err := d.NewLocalTransaction()
 	if err != nil {
 		return nil, err
 	}
-	return &tx{Tx: nTx}, nil
+	return &tx{DatabaseTx: nTx}, nil
 }
 
 // Collections returns a list of non-system tables from the database.
 func (d *database) Collections() (collections []string, err error) {
-	q := d.Builder.Select("Name").
+	q := d.Select("Name").
 		From("__Table")
 
 	iter := q.Iterator()
@@ -139,7 +180,7 @@ func (d *database) open() error {
 	if err != nil {
 		return err
 	}
-	d.Builder = b
+	d.SQLBuilder = b
 
 	openFn := func() error {
 		openFiles := atomic.LoadInt32(&fileOpenCount)
@@ -195,7 +236,7 @@ func (d *database) Err(err error) error {
 
 // StatementExec wraps the statement to execute around a transaction.
 func (d *database) StatementExec(stmt *sql.Stmt, args ...interface{}) (sql.Result, error) {
-	if d.BaseDatabase.Tx() == nil {
+	if d.BaseDatabase.Transaction() == nil {
 		var tx *sql.Tx
 		var res sql.Result
 		var err error
@@ -224,13 +265,22 @@ func (d *database) NewLocalCollection(name string) db.Collection {
 	return newTable(d, name)
 }
 
+// Tx creates a transaction and passes it to the given function, if if the
+// function returns no error then the transaction is commited.
+func (d *database) Tx(fn func(tx db.SQLTx) error) error {
+	return sqladapter.RunTx(d, fn)
+}
+
 // NewLocalTransaction allows sqladapter start a transaction block.
-func (d *database) NewLocalTransaction() (sqladapter.Tx, error) {
+func (d *database) NewLocalTransaction() (sqladapter.DatabaseTx, error) {
 	clone, err := d.clone()
 	if err != nil {
 		return nil, err
 	}
 
+	clone.txMu.Lock()
+	defer clone.txMu.Unlock()
+
 	openFn := func() error {
 		sqlTx, err := clone.BaseDatabase.Session().Begin()
 		if err == nil {
@@ -258,7 +308,7 @@ func (d *database) FindDatabaseName() (string, error) {
 // TableExists allows sqladapter check whether a table exists and returns an
 // error in case it doesn't.
 func (d *database) TableExists(name string) error {
-	q := d.Builder.Select("Name").
+	q := d.SQLBuilder.Select("Name").
 		From("__Table").
 		Where("Name == ?", name)
 

ql/ql.go

@@ -31,5 +31,9 @@ const sqlDriver = `ql`
 const Adapter = sqlDriver
 
 func init() {
-	db.Register(Adapter, &database{})
+	db.RegisterSQLAdapter(Adapter, &db.SQLAdapterFuncMap{
+		New:   New,
+		NewTx: NewTx,
+		Open:  Open,
+	})
 }

ql/template_test.go

@@ -9,7 +9,7 @@ import (
 )
 
 func TestTemplateSelect(t *testing.T) {
-	b := builder.NewBuilderWithTemplate(template)
+	b := builder.NewSQLBuilder(template)
 	assert := assert.New(t)
 
 	assert.Equal(
@@ -147,7 +147,7 @@ func TestTemplateSelect(t *testing.T) {
 }
 
 func TestTemplateInsert(t *testing.T) {
-	b := builder.NewBuilderWithTemplate(template)
+	b := builder.NewSQLBuilder(template)
 	assert := assert.New(t)
 
 	assert.Equal(
@@ -189,7 +189,7 @@ func TestTemplateInsert(t *testing.T) {
 }
 
 func TestTemplateUpdate(t *testing.T) {
-	b := builder.NewBuilderWithTemplate(template)
+	b := builder.NewSQLBuilder(template)
 	assert := assert.New(t)
 
 	assert.Equal(
@@ -231,7 +231,7 @@ func TestTemplateUpdate(t *testing.T) {
 }
 
 func TestTemplateDelete(t *testing.T) {
-	b := builder.NewBuilderWithTemplate(template)
+	b := builder.NewSQLBuilder(template)
 	assert := assert.New(t)
 
 	assert.Equal(

ql/tx.go

@@ -26,22 +26,10 @@ import (
 	"upper.io/db.v2/internal/sqladapter"
 )
 
-// Tx represents a transaction.
-type Tx interface {
-	Database
-
-	Commit() error
-	Rollback() error
-}
-
 type tx struct {
-	sqladapter.Tx
+	sqladapter.DatabaseTx
 }
 
 var (
-	_ = db.Tx(&tx{})
+	_ = db.SQLTx(&tx{})
 )
-
-func (t *tx) NewTransaction() (Tx, error) {
-	return t, db.ErrAlreadyWithinTransaction
-}