func (b *Backend) DefineField(db *sql.DB, m driver.Model, table *sql.Table, field *sql.Field) (string, []string, error) {
if field.HasOption(sql.OptionAutoIncrement) {
if field.Constraint(sql.ConstraintPrimaryKey) == nil {
return "", nil, fmt.Errorf("%s can only auto increment the primary key", b.Name())
}
}
def, constraints, err := b.SqlBackend.DefineField(db, m, table, field)
if err == nil {
def = strings.Replace(strings.Replace(def, "DEFAULT false", "DEFAULT 0", -1), "DEFAULT true", "DEFAULT 1", -1)
}
return def, constraints, err
}
func (b *Backend) AlterField(db *sql.DB, m driver.Model, table *sql.Table, oldField *sql.Field, newField *sql.Field) error {
fsql, cons, err := newField.SQL(db, m, table)
if err != nil {
return err
}
tableName := db.QuoteIdentifier(m.Table())
if _, err = db.Exec(fmt.Sprintf("ALTER TABLE %s CHANGE COLUMN %s %s", tableName, db.QuoteIdentifier(oldField.Name), fsql)); err != nil {
return err
}
for _, c := range cons {
if _, err = db.Exec(fmt.Sprintf("ALTER TABLE %s ADD CONSTRAINT %s", tableName, c)); err != nil {
return err
}
}
return err
}
func (b *Backend) DefineField(db *sql.DB, m driver.Model, table *sql.Table, field *sql.Field) (string, []string, error) {
def, cons, err := b.SqlBackend.DefineField(db, m, table, field)
if err != nil {
return "", nil, err
}
if ref := field.Constraint(sql.ConstraintForeignKey); ref != nil {
if pos := strings.Index(def, " REFERENCES"); pos >= 0 {
def = def[:pos]
}
refTable := ref.References.Table()
refField := ref.References.Field()
fkName := db.QuoteIdentifier(fmt.Sprintf("%s_%s_%s_%s", m.Table(), field.Name, refTable, refField))
cons = append(cons, fmt.Sprintf("FOREIGN KEY %s(%s) REFERENCES %s(%s)", fkName, db.QuoteIdentifier(field.Name),
db.QuoteIdentifier(refTable), db.QuoteIdentifier(refField)))
}
return strings.Replace(def, "AUTOINCREMENT", "AUTO_INCREMENT", -1), cons, nil
}
func (b *Backend) Inspect(db *sql.DB, m driver.Model) (*sql.Table, error) {
name := db.QuoteString(m.Table())
rows, err := db.Query(fmt.Sprintf("PRAGMA table_info(%s)", name))
if err != nil {
return nil, err
}
defer rows.Close()
fieldsByName := make(map[string]*sql.Field)
var fields []*sql.Field
for rows.Next() {
var cid int
var f sql.Field
var notnull int
var def *string
var pk int
if err := rows.Scan(&cid, &f.Name, &f.Type, ¬null, &def, &pk); err != nil {
return nil, err
}
f.Type = strings.ToUpper(f.Type)
if notnull != 0 {
f.AddConstraint(sql.ConstraintNotNull)
}
if def != nil {
f.Default = *def
}
if pk != 0 {
f.AddConstraint(sql.ConstraintPrimaryKey)
}
fields = append(fields, &f)
fieldsByName[f.Name] = &f
}
if err := rows.Err(); err != nil {
return nil, err
}
rows, err = db.Query(fmt.Sprintf("PRAGMA foreign_key_list(%s)", name))
if err != nil {
return nil, err
}
defer rows.Close()
for rows.Next() {
var id, seq int
var table, from, to, onUpdate, onDelete, match string
if err := rows.Scan(&id, &seq, &table, &from, &to, &onUpdate, &onDelete, &match); err != nil {
return nil, err
}
field := fieldsByName[from]
field.Constraints = append(field.Constraints, &sql.Constraint{Type: sql.ConstraintForeignKey, References: sql.MakeReference(table, to)})
}
if err := rows.Err(); err != nil {
return nil, err
}
if len(fields) > 0 {
return &sql.Table{Fields: fields}, nil
}
return nil, nil
}
func (b *Backend) canAddField(f *sql.Field) bool {
// These are a supeset of the actual resctrictions, for
// simplicity. See https://www.sqlite.org/lang_altertable.html
// for more details.
return f.Constraint(sql.ConstraintPrimaryKey) != nil && f.Constraint(sql.ConstraintUnique) == nil && f.Default == ""
}
