ent/entc: configure storage driver in codegen

Summary: Pull Request resolved: https://github.com/facebookexternal/fbc/pull/1229

Reviewed By: alexsn

Differential Revision: D16539934

fbshipit-source-id: b3a8bf1f1be6f65ad3f649cd921ea20fc24182bf

entc/gen/template/dialect/sql/decode.tmpl

@@ -0,0 +1,59 @@
+{{ define "dialect/sql/decode/one" }}
+{{ $receiver := $.Receiver }}
+
+// FromRows scans the sql response data into {{ $.Name }}.
+func ({{ $receiver }} *{{ $.Name }}) FromRows(rows *sql.Rows) error {
+	{{- $scan := print "v" $receiver }}
+	var {{ $scan }} struct {
+		ID   {{ if $.ID.IsString }}int{{ else }}{{ $.ID.Type }}{{ end }}
+		{{ range $_, $f := $.Fields }}
+			{{- pascal $f.Name }} {{ if or $f.Nullable $f.Optional }}{{ $f.NullType }}{{ else }}{{ $f.Type }}{{ end }}
+		{{ end }}
+	}
+	// the order here should be the same as in the `{{ $.Package }}.Columns`.
+	if err := rows.Scan(
+			&{{ $scan }}.ID,
+			{{- range $_, $f := $.Fields }}
+				&{{ $scan }}.{{- pascal $f.Name }},
+			{{- end }}
+	); err != nil {
+		return err
+	}
+	{{ $receiver }}.ID = {{ if $.ID.IsString }}strconv.Itoa({{ $scan }}.ID){{ else }}{{ $scan }}.ID{{ end }}
+	{{- range $_, $f := $.Fields }}
+		{{- if $f.Nullable }}
+			{{- if $f.IsTime }}
+				{{ $receiver }}.{{ pascal $f.Name }} = &{{ $scan }}.{{ pascal $f.Name }}
+			{{- else }}
+				if {{ $scan }}.{{- pascal $f.Name }}.Valid {
+					{{ $receiver }}.{{ pascal $f.Name }} = new({{ $f.Type }})
+					*{{ $receiver }}.{{ pascal $f.Name }} = {{ printf "%s.%s" $scan (pascal $f.Name) | $f.NullTypeField }}
+				}
+			{{- end }}
+		{{- else if $f.Optional }}
+			{{ $receiver }}.{{ pascal $f.Name }} = {{ printf "%s.%s" $scan (pascal $f.Name) | $f.NullTypeField }}
+		{{- else }}
+			{{ $receiver }}.{{ pascal $f.Name }} = {{ $scan }}.{{ pascal $f.Name }}
+		{{- end }}
+	{{- end }}
+	return nil
+}
+{{ end }}
+
+{{ define "dialect/sql/decode/many" }}
+{{ $receiver := $.Receiver }}
+{{ $slice := $.Scope.Slice }}
+
+// FromRows scans the sql response data into {{ $slice }}.
+func ({{ $receiver }} *{{ $slice }}) FromRows(rows *sql.Rows) error {
+	for rows.Next() {
+		{{- $scan := print "v" $receiver }}
+		{{ $scan }} := &{{ $.Name }}{}
+		if err := {{ $scan }}.FromRows(rows); err != nil {
+			return err
+		}
+		*{{ $receiver }} = append(*{{ $receiver }}, {{ $scan }})
+	}
+	return nil
+}
+{{ end }}