Add ColumnTypeMap which allows bespoke customisation of column types.

config.go

@@ -55,6 +55,7 @@ type Config struct {
 	fileNameNS  func(tableName string) (fileName string)
 
 	dataTypeMap    map[string]func(columnType gorm.ColumnType) (dataType string)
+	columnTypeMap  map[string]func(columnType gorm.ColumnType) (colType string)
 	fieldJSONTagNS func(columnName string) (tagContent string)
 
 	modelOpts []ModelOpt
@@ -98,6 +99,11 @@ func (cfg *Config) WithDataTypeMap(newMap map[string]func(columnType gorm.Column
 	cfg.dataTypeMap = newMap
 }
 
+// WithColumnTypeMap specify column type mapping relationship, only work when syncing table from db
+func (cfg *Config) WithColumnTypeMap(newMap map[string]func(columnType gorm.ColumnType) (colType string)) {
+	cfg.columnTypeMap = newMap
+}
+
 // WithJSONTagNameStrategy specify json tag naming strategy
 func (cfg *Config) WithJSONTagNameStrategy(ns func(columnName string) (tagContent string)) {
 	cfg.fieldJSONTagNS = ns

generator.go

@@ -187,7 +187,8 @@ func (g *Generator) genModelConfig(tableName string, modelName string, modelOpts
 			FileNameNS:     g.fileNameNS,
 		},
 		FieldConfig: model.FieldConfig{
-			DataTypeMap: g.dataTypeMap,
+			DataTypeMap:   g.dataTypeMap,
+			ColumnTypeMap: g.columnTypeMap,
 
 			FieldSignable:     g.FieldSignable,
 			FieldNullable:     g.FieldNullable,

internal/generate/generate.go

@@ -19,6 +19,7 @@ import (
 func getFields(db *gorm.DB, conf *model.Config, columns []*model.Column) (fields []*model.Field) {
 	for _, col := range columns {
 		col.SetDataTypeMap(conf.DataTypeMap)
+		col.SetColumnTypeMap(conf.ColumnTypeMap)
 		col.WithNS(conf.FieldJSONTagNS)
 
 		m := col.ToField(conf.FieldNullable, conf.FieldCoverable, conf.FieldSignable)

internal/generate/interface.go

@@ -127,7 +127,7 @@ func (m *InterfaceMethod) IsRepeatFromSameInterface(newMethod *InterfaceMethod)
 	return m.MethodName == newMethod.MethodName && m.InterfaceName == newMethod.InterfaceName && m.TargetStruct == newMethod.TargetStruct
 }
 
-//GetParamInTmpl return param list
+// GetParamInTmpl return param list
 func (m *InterfaceMethod) GetParamInTmpl() string {
 	return paramToString(m.Params)
 }

internal/model/config.go

@@ -33,7 +33,8 @@ type NameStrategy struct {
 
 // FieldConfig field configuration
 type FieldConfig struct {
-	DataTypeMap map[string]func(columnType gorm.ColumnType) (dataType string)
+	DataTypeMap   map[string]func(columnType gorm.ColumnType) (dataType string)
+	ColumnTypeMap map[string]func(columnType gorm.ColumnType) (colType string)
 
 	FieldNullable     bool // generate pointer when field is nullable
 	FieldCoverable    bool // generate pointer when field has default value

internal/model/tbl_column.go

@@ -12,18 +12,24 @@ import (
 // Column table column's info
 type Column struct {
 	gorm.ColumnType
-	TableName   string                                                        `gorm:"column:TABLE_NAME"`
-	Indexes     []*Index                                                      `gorm:"-"`
-	UseScanType bool                                                          `gorm:"-"`
-	dataTypeMap map[string]func(columnType gorm.ColumnType) (dataType string) `gorm:"-"`
-	jsonTagNS   func(columnName string) string                                `gorm:"-"`
+	TableName     string                                                        `gorm:"column:TABLE_NAME"`
+	Indexes       []*Index                                                      `gorm:"-"`
+	UseScanType   bool                                                          `gorm:"-"`
+	dataTypeMap   map[string]func(columnType gorm.ColumnType) (dataType string) `gorm:"-"`
+	columnTypeMap map[string]func(columnType gorm.ColumnType) (colType string)  `gorm:"-"`
+	jsonTagNS     func(columnName string) string                                `gorm:"-"`
 }
 
 // SetDataTypeMap set data type map
 func (c *Column) SetDataTypeMap(m map[string]func(columnType gorm.ColumnType) (dataType string)) {
 	c.dataTypeMap = m
 }
 
+// SetColumnTypeMap set column type map
+func (c *Column) SetColumnTypeMap(m map[string]func(columnType gorm.ColumnType) (colType string)) {
+	c.columnTypeMap = m
+}
+
 // GetDataType get data type
 func (c *Column) GetDataType() (fieldtype string) {
 	if mapping, ok := c.dataTypeMap[c.DatabaseTypeName()]; ok {
@@ -158,6 +164,9 @@ func (c *Column) defaultTagValue() string {
 
 func (c *Column) columnType() (v string) {
 	if cl, ok := c.ColumnType.ColumnType(); ok {
+		if mapping, ok := c.columnTypeMap[cl]; ok {
+			return mapping(c.ColumnType)
+		}
 		return cl
 	}
 	return c.DatabaseTypeName()