sqlmapper

README

sqlmapper is a light mapper between golang struct and table rows in db

example

We need to read/write a table in db, like:

CREATE TABLE `test_table` (
  `field_key` varchar(64) NOT NULL DEFAULT '',
  `field_one` varchar(64) DEFAULT NULL,
  `field_two` tinyint(1) DEFAULT NULL,
  `field_thr` int(12) DEFAULT NULL,
  `field_fou` float DEFAULT NULL,
  PRIMARY KEY (`field_key`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8;

In golang, we create a struct corresponding to the table, like:

// struct in go such as:
type DemoRow struct {
	FieldKey string  `sql:"field_key"`
	FieldOne string  `sql:"field_one"`
	FieldTwo bool    `sql:"field_two"`
	FieldThr int64   `sql:"field_thr"`
	FieldFou float64 `sql:"field_fou"`
}

Then, we can execute SELECT/INSERT/UPDATE/DELETE without long Hard-Code sql string which is easy to make mistakes.

sample (follow fields_map_test.go for more):

// select single row
// Query by primary key (field[0])
func QueryByKey(ctx context.Context, tx *sql.Tx, db *sql.DB, fieldKey string) (
	*DemoRow, error) {

	var row DemoRow
	row.FieldKey = fieldKey
	fm, err := NewFieldsMap(table, &row)
	if err != nil {
		return nil, err
	}

	objptr, err := fm.SQLSelectByPriKey(ctx, tx, db)
	if err != nil {
		return nil, err
	}

	return objptr.(*DemoRow), nil
}
    

Documentation

Index

• type Field
• type FieldsMap
  • func NewFieldsMap(table string, objptr interface{}) (FieldsMap, error)

Types

type Field

type Field struct {
	Name       string
	Tag        string
	Type       string
	Addr       interface{}
	IntSave    sql.NullInt64
	StringSave sql.NullString
	FloatSave  sql.NullFloat64
	BoolSave   sql.NullBool
}

Field db field describe struct mapping in DB like:

type DemoRow struct {
	FieldKey string  `sql:"field_key"`
	FieldOne string  `sql:"field_one"`
	FieldTwo bool    `sql:"field_two"`
	FieldThr int64   `sql:"field_thr"`
	FieldFou float64 `sql:"field_fou"`
}

type FieldsMap

type FieldsMap interface {

	// GetFields Fields
	GetFields() []Field

	// GetFieldNamesInDB get Names in db from Fields
	GetFieldNamesInDB() []string

	// GetFieldValues get Values in Object(struct)
	GetFieldValues() []interface{}

	// GetFieldValue get Value in Object(struct)
	GetFieldValue(idx int) interface{}

	// GetFieldSaveAddrs get Pointers of Values in Object(struct)
	GetFieldSaveAddrs() []interface{}

	// GetFieldSaveAddr get Pointer of Value in Object(struct)
	GetFieldSaveAddr(idx int) interface{}

	// MapBackToObject mapping back to the original object
	MapBackToObject() interface{}

	////////////////////////////////////////////////////////////////
	// generate SQL string
	// SQLFieldsStr generate sqlstr in db from Fields
	SQLFieldsStr() string

	// SQLFieldsStrForSet generate sqlstr in db from Fields for set
	SQLFieldsStrForSet() string

	////////////////////////////////////////////////////////////////
	// generate statement
	// PrepareStmt prepare statement
	// Must Close after Stmt used
	PrepareStmt(ctx context.Context, tx *sql.Tx, db *sql.DB,
		sqlstr string) (*sql.Stmt, error)

	// SQLSelectStmt generate statement for SELECT
	SQLSelectStmt(ctx context.Context, tx *sql.Tx, db *sql.DB,
		extStr string) (*sql.Stmt, error)

	// SQLInsertStmt generate statement for INSERT
	SQLInsertStmt(ctx context.Context, tx *sql.Tx, db *sql.DB) (*sql.Stmt, error)

	// SQLUpdateStmt generate statement for UPDATE
	SQLUpdateStmt(ctx context.Context, tx *sql.Tx, db *sql.DB,
		extStr string) (*sql.Stmt, error)

	// SQLDeleteStmt generate statement for DELETE
	SQLDeleteStmt(ctx context.Context, tx *sql.Tx, db *sql.DB,
		extStr string) (*sql.Stmt, error)

	////////////////////////////////////////////////////////////////
	// exec sql
	// SQLLockByPriKey by primary key (field[0])
	SQLLockByPriKey(ctx context.Context, tx *sql.Tx,
		db *sql.DB) (interface{}, error)

	// SQLSelectByPriKey by primary key (field[0])
	SQLSelectByPriKey(ctx context.Context, tx *sql.Tx,
		db *sql.DB) (interface{}, error)

	// SQLSelectRowsByFieldNameInDB by field name in DB
	SQLSelectRowsByFieldNameInDB(ctx context.Context, tx *sql.Tx,
		db *sql.DB, nameInDB string) ([]interface{}, error)

	// SQLSelectAllRows
	SQLSelectAllRows(ctx context.Context, tx *sql.Tx,
		db *sql.DB) ([]interface{}, error)

	// SQLInsert
	SQLInsert(ctx context.Context, tx *sql.Tx, db *sql.DB) error

	// SQLUpdateByPriKey by primary key (field[0])
	SQLUpdateByPriKey(ctx context.Context, tx *sql.Tx, db *sql.DB) error

	// SQLDeleteByPriKey by primary key (field[0])
	SQLDeleteByPriKey(ctx context.Context, tx *sql.Tx, db *sql.DB) error
}

FieldsMap hold Field

func NewFieldsMap

func NewFieldsMap(table string, objptr interface{}) (FieldsMap, error)

NewFieldsMap new Fields