Add dialects for supported databases for easier to use

CHANGELOG.md

@@ -4,7 +4,7 @@
 
 #### Breaking Changes
 
-* **`gorm.Open` return type `*gorm.DB` instead of `gorm.DB`**
+* **`gorm.Open` return `*gorm.DB` instead of `gorm.DB`**
 
 * **Updating will only update changed fields**
 
@@ -52,3 +52,5 @@
   So field `HTTP`'s db name will be `http` not `h_t_t_p`, but some other initialisms like `SKU` that not in golint, it's db name will be `s_k_u`, this release fixed this, any upper case initialisms should be converted correctly.
 
   If your applications using some upper case initialisms which doesn't exist in [golint](https://github.com/golang/lint/blob/master/lint.go#L702), you need to overwrite generated column name with tag, like `sql:"column:s_k_u"`, or alert your database's column name according to new logic
+
+* **Builtin `Hstore` struct for postgres has been moved to `github.com/jinzhu/gorm/dialects/postgres`**

dialect_postgres.go

@@ -1,14 +1,10 @@
 package gorm
 
 import (
-	"database/sql"
-	"database/sql/driver"
 	"fmt"
 	"reflect"
 	"strings"
 	"time"
-
-	"github.com/lib/pq/hstore"
 )
 
 type postgres struct {
@@ -55,7 +51,7 @@ func (postgres) DataTypeOf(field *StructField) string {
 				sqlType = "timestamp with time zone"
 			}
 		case reflect.Map:
-			if dataValue.Type() == hstoreType {
+			if dataValue.Type().Name() == "Hstore" {
 				sqlType = "hstore"
 			}
 		default:
@@ -108,51 +104,6 @@ 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))
 }

dialects/mssql/mssql.go

@@ -0,0 +1,3 @@
+package mssql
+
+import _ "github.com/denisenkom/go-mssqldb"

dialects/mysql/mysql.go

@@ -0,0 +1,3 @@
+package mysql
+
+import _ "github.com/go-sql-driver/mysql"

dialects/postgres/postgres.go

@@ -0,0 +1,52 @@
+package postgres
+
+import (
+	"database/sql"
+	"database/sql/driver"
+
+	_ "github.com/lib/pq"
+	"github.com/lib/pq/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
+}

dialects/sqlite/sqlite.go

@@ -0,0 +1,3 @@
+package sqlite
+
+import _ "github.com/mattn/go-sqlite3"

main_test.go

@@ -4,20 +4,19 @@ import (
 	"database/sql"
 	"database/sql/driver"
 	"fmt"
+	"os"
 	"reflect"
 	"strconv"
-
-	_ "github.com/denisenkom/go-mssqldb"
-	testdb "github.com/erikstmartin/go-testdb"
-	_ "github.com/go-sql-driver/mysql"
-	"github.com/jinzhu/gorm"
-	"github.com/jinzhu/now"
-	_ "github.com/lib/pq"
-	_ "github.com/mattn/go-sqlite3"
-
-	"os"
 	"testing"
 	"time"
+
+	"github.com/erikstmartin/go-testdb"
+	"github.com/jinzhu/gorm"
+	_ "github.com/jinzhu/gorm/dialects/mssql"
+	_ "github.com/jinzhu/gorm/dialects/mysql"
+	"github.com/jinzhu/gorm/dialects/postgres"
+	_ "github.com/jinzhu/gorm/dialects/sqlite"
+	"github.com/jinzhu/now"
 )
 
 var (
@@ -624,7 +623,7 @@ func TestTimeWithZone(t *testing.T) {
 func TestHstore(t *testing.T) {
 	type Details struct {
 		Id   int64
-		Bulk gorm.Hstore
+		Bulk postgres.Hstore
 	}
 
 	if dialect := os.Getenv("GORM_DIALECT"); dialect != "postgres" {