func (b *Backend) Inspect(db *sql.DB, m driver.Model) (*sql.Table, error) {
var database string
if err := db.QueryRow("SELECT DATABASE() FROM DUAL").Scan(&database); err != nil {
return nil, err
}
return b.SqlBackend.Inspect(db, m, database)
}
func (b *Backend) HasIndex(db *sql.DB, m driver.Model, idx *index.Index, name string) (bool, error) {
var exists int
err := db.QueryRow("SELECT 1 FROM pg_class WHERE relname = $1 AND relkind = 'i'", name).Scan(&exists)
if err == sql.ErrNoRows {
err = nil
}
return exists != 0, err
}
func (b *Backend) HasIndex(db *sql.DB, m driver.Model, idx *index.Index, name string) (bool, error) {
rows, err := db.Query("SHOW INDEX FROM ? WHERE Key_name = ?", m.Table(), name)
if err != nil {
return false, err
}
has := rows.Next()
rows.Close()
return has, nil
}
func (b *Backend) HasIndex(db *sql.DB, m driver.Model, idx *index.Index, name string) (bool, error) {
rows, err := db.Query(fmt.Sprintf("PRAGMA index_info(%s)", name))
if err != nil {
return false, err
}
has := rows.Next()
rows.Close()
return has, nil
}
func (b *Backend) Insert(db *sql.DB, m driver.Model, query string, args ...interface{}) (driver.Result, error) {
fields := m.Fields()
if fields.AutoincrementPk {
q := query + " RETURNING " + fields.MNames[fields.PrimaryKey]
var id int64
err := db.QueryRow(q, args...).Scan(&id)
// We need to perform a "real" insert to find the real error, so
// just let the code fall to the Exec at the end of the function
// if there's an error.
if err == nil {
return insertResult(id), nil
}
}
return db.Exec(query, args...)
}
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) AddFields(db *sql.DB, m driver.Model, prevTable *sql.Table, newTable *sql.Table, fields []*sql.Field) error {
rewrite := false
for _, v := range fields {
if !b.canAddField(v) {
rewrite = true
break
}
}
if rewrite {
name := db.QuoteIdentifier(m.Table())
tmpName := fmt.Sprintf("%s_%s", m.Table(), stringutil.Random(8))
quotedTmpName := db.QuoteIdentifier(tmpName)
createSql, err := newTable.SQL(db, b, m, tmpName)
if err != nil {
return err
}
if _, err := db.Exec(createSql); err != nil {
return err
}
fieldNames := generic.Map(prevTable.Fields, func(f *sql.Field) string { return f.Name }).([]string)
// The previous table might have fields that we're not part
// of the new table.
fieldSet := make(map[string]bool)
for _, v := range newTable.Fields {
fieldSet[v.Name] = true
}
fieldNames = generic.Filter(fieldNames, func(n string) bool { return fieldSet[n] }).([]string)
sqlFields := strings.Join(generic.Map(fieldNames, db.QuoteIdentifier).([]string), ", ")
copySql := fmt.Sprintf("INSERT INTO %s (%s) SELECT %s FROM %s", quotedTmpName, sqlFields, sqlFields, name)
if _, err := db.Exec(copySql); err != nil {
return err
}
if _, err := db.Exec(fmt.Sprintf("DROP TABLE %s", name)); err != nil {
return err
}
if _, err := db.Exec(fmt.Sprintf("ALTER TABLE %s RENAME TO %s", quotedTmpName, name)); err != nil {
return err
}
return nil
}
return b.SqlBackend.AddFields(db, m, prevTable, newTable, fields)
}