enable sql dialect option on integration env (#1014)

Summary:
Pull Request resolved: https://github.com/facebookexternal/fbc/pull/1014

Pull Request resolved: https://github.com/facebookincubator/ent/pull/6

Reviewed By: alexsn

Differential Revision: D15928002

fbshipit-source-id: 4b5a639405f218f6b6cc90d152380d2fc9525a3f

dialect/sql/driver.go

@@ -5,6 +5,7 @@ import (
 	"database/sql"
 	"database/sql/driver"
 	"fmt"
+	"strings"
 	"time"
 
 	"fbc/ent/dialect"
@@ -31,7 +32,15 @@ func OpenDB(driver string, db *sql.DB) *Driver {
 }
 
 // Dialect implements the dialect.Dialect method.
-func (d Driver) Dialect() string { return d.dialect }
+func (d Driver) Dialect() string {
+	// if the underlying driver is wrapped with opencensus driver.
+	for _, name := range []string{dialect.MySQL, dialect.SQLite} {
+		if strings.HasPrefix(d.dialect, name) {
+			return name
+		}
+	}
+	return d.dialect
+}
 
 // Tx starts and returns a transaction.
 func (d *Driver) Tx(ctx context.Context) (dialect.Tx, error) {

dialect/sql/schema/mysql.go

@@ -170,7 +170,7 @@ func changeSet(curr, new *Table) (*Table, error) {
 		case !ok:
 			changes.Columns = append(changes.Columns, c1)
 		case c1.Type != c2.Type:
-			return nil, fmt.Errorf("changing column type for %q is invalid", c1.Name)
+			return nil, fmt.Errorf("changing column type for %q is invalid (%s != %s)", c1.Name, c1.Type, c2.Type)
 		case c1.Unique != c2.Unique:
 			return nil, fmt.Errorf("changing column cardinality for %q is invalid", c1.Name)
 		}

dialect/sql/schema/schema.go

@@ -226,6 +226,8 @@ func (c *Column) ScanMySQL(rows *sql.Rows) error {
 	}); parts[0] {
 	case "int":
 		c.Type = field.TypeInt
+	case "double":
+		c.Type = field.TypeFloat64
 	case "timestamp":
 		c.Type = field.TypeTime
 	case "tinyint":