gorm/dialect_postgres.go

153 lines
3.6 KiB
Go

package gorm
import (
"database/sql"
"database/sql/driver"
"fmt"
"reflect"
"strings"
"time"
"github.com/lib/pq/hstore"
)
type postgres struct {
commonDialect
}
func (postgres) BindVar(i int) string {
return fmt.Sprintf("$%v", i)
}
func (postgres) DataTypeOf(value reflect.Value, size int, autoIncrease bool) string {
switch value.Kind() {
case reflect.Bool:
return "boolean"
case reflect.Int, reflect.Int8, reflect.Int16, reflect.Int32, reflect.Uint, reflect.Uint8, reflect.Uint16, reflect.Uint32, reflect.Uintptr:
if autoIncrease {
return "serial"
}
return "integer"
case reflect.Int64, reflect.Uint64:
if autoIncrease {
return "bigserial"
}
return "bigint"
case reflect.Float32, reflect.Float64:
return "numeric"
case reflect.String:
if size > 0 && size < 65532 {
return fmt.Sprintf("varchar(%d)", size)
}
return "text"
case reflect.Struct:
if _, ok := value.Interface().(time.Time); ok {
return "timestamp with time zone"
}
case reflect.Map:
if value.Type() == hstoreType {
return "hstore"
}
default:
if isByteArrayOrSlice(value) {
return "bytea"
} else if isUUID(value) {
return "uuid"
}
}
panic(fmt.Sprintf("invalid sql type %s (%s) for postgres", value.Type().Name(), value.Kind().String()))
}
func (s postgres) HasIndex(scope *Scope, tableName string, indexName string) bool {
var count int
s.RawScanInt(scope, &count, "SELECT count(*) FROM pg_indexes WHERE tablename = ? AND indexname = ?", tableName, indexName)
return count > 0
}
func (postgres) RemoveIndex(scope *Scope, indexName string) {
scope.Err(scope.NewDB().Exec(fmt.Sprintf("DROP INDEX %v", indexName)).Error)
}
func (s postgres) HasTable(scope *Scope, tableName string) bool {
var count int
s.RawScanInt(scope, &count, "SELECT count(*) FROM INFORMATION_SCHEMA.tables WHERE table_name = ? AND table_type = 'BASE TABLE'", tableName)
return count > 0
}
func (s postgres) HasColumn(scope *Scope, tableName string, columnName string) bool {
var count int
s.RawScanInt(scope, &count, "SELECT count(*) FROM INFORMATION_SCHEMA.columns WHERE table_name = ? AND column_name = ?", tableName, columnName)
return count > 0
}
func (s postgres) currentDatabase(scope *Scope) (name string) {
s.RawScanString(scope, &name, "SELECT CURRENT_DATABASE()")
return
}
func (s postgres) LastInsertIdReturningSuffix(tableName, key string) string {
return fmt.Sprintf("RETURNING %v.%v", tableName, key)
}
func (postgres) SupportLastInsertId() bool {
return false
}
var hstoreType = reflect.TypeOf(Hstore{})
type Hstore map[string]*string
func (h Hstore) Value() (driver.Value, error) {
hstore := hstore.Hstore{Map: map[string]sql.NullString{}}
if len(h) == 0 {
return nil, nil
}
for key, value := range h {
var s sql.NullString
if value != nil {
s.String = *value
s.Valid = true
}
hstore.Map[key] = s
}
return hstore.Value()
}
func (h *Hstore) Scan(value interface{}) error {
hstore := hstore.Hstore{}
if err := hstore.Scan(value); err != nil {
return err
}
if len(hstore.Map) == 0 {
return nil
}
*h = Hstore{}
for k := range hstore.Map {
if hstore.Map[k].Valid {
s := hstore.Map[k].String
(*h)[k] = &s
} else {
(*h)[k] = nil
}
}
return nil
}
func isByteArrayOrSlice(value reflect.Value) bool {
return (value.Kind() == reflect.Array || value.Kind() == reflect.Slice) && value.Type().Elem() == reflect.TypeOf(uint8(0))
}
func isUUID(value reflect.Value) bool {
if value.Kind() != reflect.Array || value.Type().Len() != 16 {
return false
}
typename := value.Type().Name()
lower := strings.ToLower(typename)
return "uuid" == lower || "guid" == lower
}