gorm/dialect_postgres.go

133 lines
3.6 KiB
Go

package gorm
import (
"fmt"
"reflect"
"strings"
"time"
)
type postgres struct {
commonDialect
}
func init() {
RegisterDialect("postgres", &postgres{})
}
func (postgres) GetName() string {
return "postgres"
}
func (postgres) BindVar(i int) string {
return fmt.Sprintf("$%v", i)
}
func (postgres) DataTypeOf(field *StructField) string {
var dataValue, sqlType, size, additionalType = ParseFieldStructForDialect(field)
if sqlType == "" {
switch dataValue.Kind() {
case reflect.Bool:
sqlType = "boolean"
case reflect.Int, reflect.Int8, reflect.Int16, reflect.Int32, reflect.Uint, reflect.Uint8, reflect.Uint16, reflect.Uint32, reflect.Uintptr:
if _, ok := field.TagSettings["AUTO_INCREMENT"]; ok || field.IsPrimaryKey {
sqlType = "serial"
} else {
sqlType = "integer"
}
case reflect.Int64, reflect.Uint64:
if _, ok := field.TagSettings["AUTO_INCREMENT"]; ok || field.IsPrimaryKey {
sqlType = "bigserial"
} else {
sqlType = "bigint"
}
case reflect.Float32, reflect.Float64:
sqlType = "numeric"
case reflect.String:
if _, ok := field.TagSettings["SIZE"]; !ok {
size = 0 // if SIZE haven't been set, use `text` as the default type, as there are no performance different
}
if size > 0 && size < 65532 {
sqlType = fmt.Sprintf("varchar(%d)", size)
} else {
sqlType = "text"
}
case reflect.Struct:
if _, ok := dataValue.Interface().(time.Time); ok {
sqlType = "timestamp with time zone"
}
case reflect.Map:
if dataValue.Type().Name() == "Hstore" {
sqlType = "hstore"
}
default:
if isByteArrayOrSlice(dataValue) {
sqlType = "bytea"
} else if isUUID(dataValue) {
sqlType = "uuid"
}
}
}
if sqlType == "" {
panic(fmt.Sprintf("invalid sql type %s (%s) for postgres", dataValue.Type().Name(), dataValue.Kind().String()))
}
if strings.TrimSpace(additionalType) == "" {
return sqlType
}
return fmt.Sprintf("%v %v", sqlType, additionalType)
}
func (s postgres) HasIndex(tableName string, indexName string) bool {
var count int
s.db.QueryRow("SELECT count(*) FROM pg_indexes WHERE tablename = $1 AND indexname = $2", tableName, indexName).Scan(&count)
return count > 0
}
func (s postgres) HasForeignKey(tableName string, foreignKeyName string) bool {
var count int
s.db.QueryRow("SELECT count(con.conname) FROM pg_constraint con WHERE $1::regclass::oid = con.conrelid AND con.conname = $2 AND con.contype='f'", tableName, foreignKeyName).Scan(&count)
return count > 0
}
func (s postgres) HasTable(tableName string) bool {
var count int
s.db.QueryRow("SELECT count(*) FROM INFORMATION_SCHEMA.tables WHERE table_name = $1 AND table_type = 'BASE TABLE'", tableName).Scan(&count)
return count > 0
}
func (s postgres) HasColumn(tableName string, columnName string) bool {
var count int
s.db.QueryRow("SELECT count(*) FROM INFORMATION_SCHEMA.columns WHERE table_name = $1 AND column_name = $2", tableName, columnName).Scan(&count)
return count > 0
}
func (s postgres) currentDatabase() (name string) {
s.db.QueryRow("SELECT CURRENT_DATABASE()").Scan(&name)
return
}
func (s postgres) LastInsertIDReturningSuffix(tableName, key string) string {
return fmt.Sprintf("RETURNING %v.%v", tableName, key)
}
func (postgres) SupportLastInsertID() bool {
return false
}
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
}