Fixes #69: support customizable table name mapping

README.md

@@ -490,6 +490,15 @@ If you want to use a different field as the primary key, tag it with `db:"pk"`.
 for composite primary keys. Note that if you also want to explicitly specify the column name for a primary key field,
 you should use the tag format `db:"pk,col_name"`.
 
+You can give a common prefix or suffix to your table names by defining your own table name mapping via 
+`DB.TableMapFunc`. For example, the following code prefixes `tbl_` to all table names. 
+
+```go
+db.TableMapper = func(a interface{}) string {
+    return "tbl_" + GetTableName(a)
+}
+```
+
 ### Create
 
 To create (insert) a new row using a model, call the `ModelQuery.Insert()` method. For example,

db.go

@@ -48,6 +48,8 @@ type (
 
 		// FieldMapper maps struct fields to DB columns. Defaults to DefaultFieldMapFunc.
 		FieldMapper FieldMapFunc
+		// TableMapper maps structs to table names. Defaults to GetTableName.
+		TableMapper TableMapFunc
 		// LogFunc logs the SQL statements being executed. Defaults to nil, meaning no logging.
 		LogFunc LogFunc
 		// PerfFunc logs the SQL execution time. Defaults to nil, meaning no performance profiling.
@@ -85,6 +87,7 @@ func NewFromDB(sqlDB *sql.DB, driverName string) *DB {
 		driverName:  driverName,
 		sqlDB:       sqlDB,
 		FieldMapper: DefaultFieldMapFunc,
+		TableMapper: GetTableName,
 	}
 	db.Builder = db.newBuilder(db.sqlDB)
 	return db
@@ -121,6 +124,7 @@ func (db *DB) Clone() *DB {
 		driverName:   db.driverName,
 		sqlDB:        db.sqlDB,
 		FieldMapper:  db.FieldMapper,
+		TableMapper:  db.TableMapper,
 		PerfFunc:     db.PerfFunc,
 		LogFunc:      db.LogFunc,
 		QueryLogFunc: db.QueryLogFunc,

db_test.go

@@ -359,3 +359,21 @@ func getPreparedDB() *DB {
 	}
 	return db
 }
+
+// Naming according to issue 49 ( https://github.com/go-ozzo/ozzo-dbx/issues/49 )
+
+type ArtistDAO struct {
+	nickname string
+}
+
+func (ArtistDAO) TableName() string {
+	return "artists"
+}
+
+func Test_TableNameWithPrefix(t *testing.T) {
+	db := NewFromDB(nil, "mysql")
+	db.TableMapper = func(a interface{}) string {
+		return "tbl_" + GetTableName(a)
+	}
+	assert.Equal(t, "tbl_artists", db.TableMapper(ArtistDAO{}))
+}

model_query.go

@@ -34,7 +34,7 @@ func NewModelQuery(model interface{}, fieldMapFunc FieldMapFunc, db *DB, builder
 		db:      db,
 		ctx:     db.ctx,
 		builder: builder,
-		model:   newStructValue(model, fieldMapFunc),
+		model:   newStructValue(model, fieldMapFunc, db.TableMapper),
 	}
 	if q.model == nil {
 		q.lastError = VarTypeError("must be a pointer to a struct representing the model")

select.go

@@ -15,6 +15,8 @@ import (
 type SelectQuery struct {
 	// FieldMapper maps struct field names to DB column names.
 	FieldMapper FieldMapFunc
+	// TableMapper maps structs to DB table names.
+	TableMapper TableMapFunc
 
 	builder Builder
 	ctx     context.Context
@@ -61,6 +63,7 @@ func NewSelectQuery(builder Builder, db *DB) *SelectQuery {
 		params:      Params{},
 		ctx:         db.ctx,
 		FieldMapper: db.FieldMapper,
+		TableMapper: db.TableMapper,
 	}
 }
 
@@ -286,7 +289,7 @@ func (s *SelectQuery) Build() *Query {
 // Note that when the query has no rows in the result set, an sql.ErrNoRows will be returned.
 func (s *SelectQuery) One(a interface{}) error {
 	if len(s.from) == 0 {
-		if tableName := GetTableName(a); tableName != "" {
+		if tableName := s.TableMapper(a); tableName != "" {
 			s.from = []string{tableName}
 		}
 	}
@@ -327,7 +330,7 @@ func (s *SelectQuery) Model(pk, model interface{}) error {
 // or the TableName() method if the slice element implements the TableModel interface.
 func (s *SelectQuery) All(slice interface{}) error {
 	if len(s.from) == 0 {
-		if tableName := GetTableName(slice); tableName != "" {
+		if tableName := s.TableMapper(slice); tableName != "" {
 			s.from = []string{tableName}
 		}
 	}

struct.go

@@ -16,6 +16,9 @@ type (
 	// FieldMapFunc converts a struct field name into a DB column name.
 	FieldMapFunc func(string) string
 
+	// TableMapFunc converts a sample struct into a DB table name.
+	TableMapFunc func(a interface{}) string
+
 	structInfo struct {
 		nameMap   map[string]*fieldInfo // mapping from struct field names to field infos
 		dbNameMap map[string]*fieldInfo // mapping from db column names to field infos
@@ -77,16 +80,16 @@ func getStructInfo(a reflect.Type, mapper FieldMapFunc) *structInfo {
 	return si
 }
 
-func newStructValue(model interface{}, mapper FieldMapFunc) *structValue {
+func newStructValue(model interface{}, fieldMapFunc FieldMapFunc, tableMapFunc TableMapFunc) *structValue {
 	value := reflect.ValueOf(model)
 	if value.Kind() != reflect.Ptr || value.Elem().Kind() != reflect.Struct || value.IsNil() {
 		return nil
 	}
 
 	return &structValue{
-		structInfo: getStructInfo(reflect.TypeOf(model).Elem(), mapper),
+		structInfo: getStructInfo(reflect.TypeOf(model).Elem(), fieldMapFunc),
 		value:      value.Elem(),
-		tableName:  GetTableName(model),
+		tableName:  tableMapFunc(model),
 	}
 }
 
@@ -246,8 +249,9 @@ func indirect(v reflect.Value) reflect.Value {
 	return v
 }
 
-// GetTableName returns the table name corresponding to the given model struct or slice of structs.
-// Do not call this method in the model's TableName() method, or it will cause infinite loop.
+// GetTableName implements the default way of determining the table name corresponding to the given model struct
+// or slice of structs. To get the actual table name for a model, you should use DB.TableMapFunc() instead.
+// Do not call this method in a model's TableName() method because it will cause infinite loop.
 func GetTableName(a interface{}) string {
 	if tm, ok := a.(TableModel); ok {
 		v := reflect.ValueOf(a)

struct_test.go

@@ -74,7 +74,7 @@ func Test_structValue_columns(t *testing.T) {
 		Status: 2,
 		Email:  "[email protected]",
 	}
-	sv := newStructValue(&customer, DefaultFieldMapFunc)
+	sv := newStructValue(&customer, DefaultFieldMapFunc, GetTableName)
 	cols := sv.columns(nil, nil)
 	assert.Equal(t, map[string]interface{}{"id": 1, "name": "abc", "status": 2, "email": "[email protected]", "address": sql.NullString{}}, cols)
 
@@ -87,7 +87,7 @@ func Test_structValue_columns(t *testing.T) {
 	cols = sv.columns(nil, []string{"ID", "Address"})
 	assert.Equal(t, map[string]interface{}{"name": "abc", "status": 2, "email": "[email protected]"}, cols)
 
-	sv = newStructValue(&customer, nil)
+	sv = newStructValue(&customer, nil, GetTableName)
 	cols = sv.columns([]string{"ID", "Name"}, []string{"ID"})
 	assert.Equal(t, map[string]interface{}{"Name": "abc"}, cols)
 }
@@ -103,22 +103,22 @@ func TestIssue37(t *testing.T) {
 		Customer
 		Status string
 	}{customer, "20"}
-	sv := newStructValue(&ev, nil)
+	sv := newStructValue(&ev, nil, GetTableName)
 	cols := sv.columns([]string{"ID", "Status"}, nil)
 	assert.Equal(t, map[string]interface{}{"ID": 1, "Status": "20"}, cols)
 
 	ev2 := struct {
 		Status string
 		Customer
 	}{"20", customer}
-	sv = newStructValue(&ev2, nil)
+	sv = newStructValue(&ev2, nil, GetTableName)
 	cols = sv.columns([]string{"ID", "Status"}, nil)
 	assert.Equal(t, map[string]interface{}{"ID": 1, "Status": "20"}, cols)
 }
 
 type MyCustomer struct{}
 
-func Test_getTableName(t *testing.T) {
+func TestGetTableName(t *testing.T) {
 	var c1 Customer
 	assert.Equal(t, "customer", GetTableName(c1))