package numbersix
import (
"errors"
"reflect"
)
// Set the value(s) for a subject and predicate. Only unique values are stored
// per (subject, predicate) combination, and insertion order is not retained.
func (d *DB) Set(subject, predicate string, value interface{}, more ...interface{}) error {
if len(more) > 0 {
return d.SetMany(subject, predicate, append(more, value))
}
v, err := marshal(value)
if err != nil {
return err
}
_, err = d.db.Exec("INSERT OR REPLACE INTO "+d.name+"(subject, predicate, value) VALUES(?, ?, ?)",
subject,
predicate,
v)
return err
}
// SetMany is the same as Set, but takes a slice of values to set.
func (d *DB) SetMany(subject, predicate string, values interface{}) error {
rv := reflect.ValueOf(values)
if rv.Kind() != reflect.Slice {
return errors.New("SetMany expected a slice of values")
}
if rv.Len() == 0 {
return nil
}
tx, err := d.db.Begin()
if err != nil {
return err
}
stmt, err := tx.Prepare("INSERT OR REPLACE INTO " + d.name + "(subject, predicate, value) VALUES(?, ?, ?)")
if err != nil {
return err
}
for i := 0; i < rv.Len(); i++ {
v, _ := marshal(rv.Index(i).Interface())
_, err = stmt.Exec(subject, predicate, v)
}
if err != nil {
terr := tx.Rollback()
if terr != nil {
return terr
}
return err
}
return tx.Commit()
}
// SetProperties is the same as Set, but takes a map of predicates and values to
// set.
func (d *DB) SetProperties(subject string, properties map[string][]interface{}) error {
tx, err := d.db.Begin()
if err != nil {
return err
}
stmt, err := tx.Prepare("INSERT OR REPLACE INTO " + d.name + "(subject, predicate, value) VALUES(?, ?, ?)")
if err != nil {
return err
}
for predicate, values := range properties {
for _, value := range values {
v, _ := marshal(value)
_, err = stmt.Exec(subject, predicate, v)
}
}
if err != nil {
terr := tx.Rollback()
if terr != nil {
return terr
}
return err
}
return tx.Commit()
}