goctl model reactor (#15)

* reactor sql generation

* reactor sql generation

* add console & example

* optimize unit test & add document

* modify default config

* remove test file

* Revert "remove test file"

This reverts commit 81041f9e

* fix stringx.go & optimize example

* remove unused code

tools/goctl/model/sql/builderx/builder.go

@@ -0,0 +1,97 @@
+package builderx
+
+import (
+	"fmt"
+	"reflect"
+
+	"github.com/go-xorm/builder"
+)
+
+const dbTag = "db"
+
+func NewEq(in interface{}) builder.Eq {
+	return builder.Eq(ToMap(in))
+}
+
+func NewGt(in interface{}) builder.Gt {
+	return builder.Gt(ToMap(in))
+}
+
+func ToMap(in interface{}) map[string]interface{} {
+	out := make(map[string]interface{})
+	v := reflect.ValueOf(in)
+	if v.Kind() == reflect.Ptr {
+		v = v.Elem()
+	}
+	// we only accept structs
+	if v.Kind() != reflect.Struct {
+		panic(fmt.Errorf("ToMap only accepts structs; got %T", v))
+	}
+	typ := v.Type()
+	for i := 0; i < v.NumField(); i++ {
+		// gets us a StructField
+		fi := typ.Field(i)
+		if tagv := fi.Tag.Get(dbTag); tagv != "" {
+			// set key of map to value in struct field
+			val := v.Field(i)
+			zero := reflect.Zero(val.Type()).Interface()
+			current := val.Interface()
+
+			if reflect.DeepEqual(current, zero) {
+				continue
+			}
+			out[tagv] = current
+		}
+	}
+	return out
+}
+
+func FieldNames(in interface{}) []string {
+	out := make([]string, 0)
+	v := reflect.ValueOf(in)
+	if v.Kind() == reflect.Ptr {
+		v = v.Elem()
+	}
+	// we only accept structs
+	if v.Kind() != reflect.Struct {
+		panic(fmt.Errorf("ToMap only accepts structs; got %T", v))
+	}
+	typ := v.Type()
+	for i := 0; i < v.NumField(); i++ {
+		// gets us a StructField
+		fi := typ.Field(i)
+		if tagv := fi.Tag.Get(dbTag); tagv != "" {
+			out = append(out, tagv)
+		} else {
+			out = append(out, fi.Name)
+		}
+	}
+	return out
+}
+func FieldNamesAlias(in interface{}, alias string) []string {
+	out := make([]string, 0)
+	v := reflect.ValueOf(in)
+	if v.Kind() == reflect.Ptr {
+		v = v.Elem()
+	}
+	// we only accept structs
+	if v.Kind() != reflect.Struct {
+		panic(fmt.Errorf("ToMap only accepts structs; got %T", v))
+	}
+	typ := v.Type()
+	for i := 0; i < v.NumField(); i++ {
+		// gets us a StructField
+		fi := typ.Field(i)
+		tagName := ""
+		if tagv := fi.Tag.Get(dbTag); tagv != "" {
+			tagName = tagv
+		} else {
+			tagName = fi.Name
+		}
+		if len(alias) > 0 {
+			tagName = alias + "." + tagName
+		}
+		out = append(out, tagName)
+	}
+	return out
+}