Golang Statement.Extra方法代码示例

// Appends an item (map or struct) into the collection.
func (self *table) Append(item interface{}) (interface{}, error) {
	var pKey string
	var columns sqlgen.Columns
	var values sqlgen.Values
	var arguments []interface{}
	var id int64

	cols, vals, err := self.FieldValues(item, toInternal)

	if err != nil {
		return nil, err
	}

	columns = make(sqlgen.Columns, 0, len(cols))
	for i := range cols {
		columns = append(columns, sqlgen.Column{cols[i]})
	}

	arguments = make([]interface{}, 0, len(vals))
	values = make(sqlgen.Values, 0, len(vals))
	for i := range vals {
		switch v := vals[i].(type) {
		case sqlgen.Value:
			// Adding value.
			values = append(values, v)
		default:
			// Adding both value and placeholder.
			values = append(values, sqlPlaceholder)
			arguments = append(arguments, v)
		}
	}

	if pKey, err = self.source.getPrimaryKey(self.tableN(0)); err != nil {
		if err != sql.ErrNoRows {
			// Can't tell primary key.
			return nil, err
		}
	}

	stmt := sqlgen.Statement{
		Type:    sqlgen.SqlInsert,
		Table:   sqlgen.Table{self.tableN(0)},
		Columns: columns,
		Values:  values,
	}

	if pKey == "" {
		// No primary key found.
		var res sql.Result
		if res, err = self.source.doExec(stmt, arguments...); err != nil {
			return nil, err
		}

		// Attempt to use LastInsertId() (probably won't work, but the exec()
		// succeeded, so the error from LastInsertId() is ignored).
		id, _ = res.LastInsertId()

		return id, nil
	} else {
		var row *sql.Row

		// A primary key was found.
		stmt.Extra = sqlgen.Extra(fmt.Sprintf(`RETURNING "%s"`, pKey))
		if row, err = self.source.doQueryRow(stmt, arguments...); err != nil {
			return nil, err
		}

		// Retrieving key value.
		if err = row.Scan(&id); err != nil {
			if err == sql.ErrNoRows {
				// Can't tell the row's id. Maybe there isn't any?
				return nil, nil
			}
			// Other kind of error.
			return nil, err
		}
		return id, nil
	}

	return nil, nil
}

// Appends an item (map or struct) into the collection.
func (t *table) Append(item interface{}) (interface{}, error) {

	var pKey []string
	var columns sqlgen.Columns
	var values sqlgen.Values
	var arguments []interface{}
	//var id []interface{}

	cols, vals, err := t.FieldValues(item, toInternal)

	if err != nil {
		return nil, err
	}

	columns = make(sqlgen.Columns, 0, len(cols))
	for i := range cols {
		columns = append(columns, sqlgen.Column{cols[i]})
	}

	arguments = make([]interface{}, 0, len(vals))
	values = make(sqlgen.Values, 0, len(vals))
	for i := range vals {
		switch v := vals[i].(type) {
		case sqlgen.Value:
			// Adding value.
			values = append(values, v)
		default:
			// Adding both value and placeholder.
			values = append(values, sqlPlaceholder)
			arguments = append(arguments, v)
		}
	}

	if pKey, err = t.source.getPrimaryKey(t.tableN(0)); err != nil {
		if err != sql.ErrNoRows {
			// Can't tell primary key.
			return nil, err
		}
	}

	stmt := sqlgen.Statement{
		Type:    sqlgen.SqlInsert,
		Table:   sqlgen.Table{t.tableN(0)},
		Columns: columns,
		Values:  values,
	}

	// No primary keys defined.
	if len(pKey) == 0 {
		var res sql.Result

		if res, err = t.source.doExec(stmt, arguments...); err != nil {
			return nil, err
		}

		// Attempt to use LastInsertId() (probably won't work, but the exec()
		// succeeded, so the error from LastInsertId() is ignored).
		lastID, _ := res.LastInsertId()

		return lastID, nil
	}

	var rows *sql.Rows

	// A primary key was found.
	stmt.Extra = sqlgen.Extra(fmt.Sprintf(`RETURNING "%s"`, strings.Join(pKey, `", "`)))
	if rows, err = t.source.doQuery(stmt, arguments...); err != nil {
		return nil, err
	}

	defer rows.Close()

	var keyMap map[string]interface{}
	err = sqlutil.FetchRow(rows, &keyMap)

	// Does the item satisfy the db.IDSetter interface?
	if setter, ok := item.(db.IDSetter); ok {
		if err := setter.SetID(keyMap); err != nil {
			return nil, err
		}
		return nil, nil
	}

	// The IDSetter interface does not match, we'll be looking for another
	// interface match.
	if len(keyMap) == 1 {

		id := keyMap[pKey[0]]

		// Matches db.Int64IDSetter
		if setter, ok := item.(db.Int64IDSetter); ok {
			if err = setter.SetID(to.Int64(id)); err != nil {
				return nil, err
			}
			return nil, nil
		}

		// Matches db.Uint64IDSetter
		if setter, ok := item.(db.Uint64IDSetter); ok {
//.........这里部分代码省略.........