// SchemaFromModel allows the easy construction of a TableSchema from a Go
// struct. Columns are created for each exported field in the struct. The "db"
// struct tag is used to control the mapping of field name to column name and
// to indicate exported fields which should be skipped.
//
// type User struct {
// ID int
// Name string `db:"old_name"`
// Ignored int `db:"-"`
// }
//
// Indexes are specified using the "roach" struct tag declaration.
//
// type User struct {
// ID int `roach:"primary key"`
// Name string `db:"old_name" roach:"index"`
// }
//
// The following "roach" options are supported:
//
// "primary key [(columns...)]" - creates a unique index on <columns> and
// marks it as the primary key for the table. If <columns> is not specified
// it defaults to the name of the column the option is associated with.
//
// "index" [(columns...)]" - creates an index on <columns>.
//
// "unique index" [(columns...)]" - creates a unique index on <columns>.
func SchemaFromModel(obj interface{}) (structured.TableSchema, error) {
s := structured.TableSchema{}
m, err := getDBFields(deref(reflect.TypeOf(obj)))
if err != nil {
return s, err
}
s.Table.Name = strings.ToLower(reflect.TypeOf(obj).Name())
// Create the columns for the table.
for name := range m {
col := structured.Column{
Name: name,
Type: structured.Column_BYTES,
}
s.Columns = append(s.Columns, col)
}
// Create the indexes for the table.
for name, f := range m {
tag := f.Tag.Get("roach")
if tag == "" {
continue
}
for _, opt := range strings.Split(tag, ";") {
match := schemaOptRE.FindStringSubmatch(opt)
if match == nil {
return s, fmt.Errorf("invalid schema option: %s", opt)
}
cmd := match[1]
var params []string
if len(match[2]) > 0 {
params = strings.Split(match[2], ",")
} else {
params = []string{name}
}
var index structured.Index
switch strings.ToLower(cmd) {
case "primary key":
index.Name = structured.PrimaryKeyIndexName
index.Unique = true
case "unique index":
index.Name = strings.Join(params, ":")
index.Unique = true
case "index":
index.Name = strings.Join(params, ":")
}
s.Indexes = append(s.Indexes, structured.TableSchema_IndexByName{
Index: index,
ColumnNames: params,
})
}
}
// Normalize the column and index order.
sort.Sort(columnsByName(s.Columns))
sort.Sort(indexesByName(s.Indexes))
return s, nil
}
// SchemaFromModel allows the easy construction of a TableSchema from a Go
// struct. Columns are created for each exported field in the struct. The "db"
// struct tag is used to control the mapping of field name to column name and
// to indicate exported fields which should be skipped.
//
// type User struct {
// ID int
// Name string `db:"old_name"`
// Ignored int `db:"-"`
// }
//
// Indexes are specified using the "roach" struct tag declaration.
//
// type User struct {
// ID int `roach:"primary key"`
// Name string `db:"old_name" roach:"index"`
// }
//
// The following "roach" options are supported:
//
// "primary key [(columns...)]" - creates a unique index on <columns> and
// marks it as the primary key for the table. If <columns> is not specified
// it defaults to the name of the column the option is associated with.
//
// "index" [(columns...)]" - creates an index on <columns>.
//
// "unique index" [(columns...)]" - creates a unique index on <columns>.
func SchemaFromModel(obj interface{}) (structured.TableSchema, error) {
s := structured.TableSchema{}
m, err := getDBFields(deref(reflect.TypeOf(obj)))
if err != nil {
return s, err
}
s.Table.Name = strings.ToLower(reflect.TypeOf(obj).Name())
// Create the columns for the table.
for name, sf := range m {
colType := structured.ColumnType{}
// TODO(pmattis): The mapping from Go-type Kind to column-type Kind is
// likely not complete or correct, but this is probably going away pretty
// soon with the move to SQL.
switch sf.Type.Kind() {
case reflect.Bool, reflect.Int, reflect.Int8, reflect.Int16, reflect.Int32,
reflect.Int64, reflect.Uint, reflect.Uint8, reflect.Uint16, reflect.Uint32,
reflect.Uint64, reflect.Uintptr:
colType.Kind = structured.ColumnType_INT
case reflect.Float32, reflect.Float64:
colType.Kind = structured.ColumnType_FLOAT
case reflect.String:
colType.Kind = structured.ColumnType_TEXT
}
col := structured.Column{
Name: name,
Type: colType,
}
s.Columns = append(s.Columns, col)
}
// Create the indexes for the table.
for name, f := range m {
tag := f.Tag.Get("roach")
if tag == "" {
continue
}
for _, opt := range strings.Split(tag, ";") {
match := schemaOptRE.FindStringSubmatch(opt)
if match == nil {
return s, fmt.Errorf("invalid schema option: %s", opt)
}
cmd := match[1]
var params []string
if len(match[2]) > 0 {
params = strings.Split(match[2], ",")
} else {
params = []string{name}
}
var index structured.Index
switch strings.ToLower(cmd) {
case "primary key":
index.Name = structured.PrimaryKeyIndexName
index.Unique = true
case "unique index":
index.Name = strings.Join(params, ":")
index.Unique = true
case "index":
index.Name = strings.Join(params, ":")
}
s.Indexes = append(s.Indexes, structured.TableSchema_IndexByName{
Index: index,
ColumnNames: params,
})
}
}
// Normalize the column and index order.
sort.Sort(columnsByName(s.Columns))
sort.Sort(indexesByName(s.Indexes))
return s, nil
}
