You are an expert in writing code in many different languages. Your goal is to perform code completion for the following code, keeping in mind the rest of the code and the file meta data.
    Metadata details:
    filename: tag.xo.go
    path of file: ./repos/xo/_examples/django/mysql
    
    the code of the file until where you have to start completion: package mysql

// Code generated by xo. DO NOT EDIT.

import (
	"context"
)

// Tag represents a row from 'django.tags'.
type Tag struct {
	TagID int64  `json:"tag_id"` // tag_id
	Tag   string `json:"tag"`    // tag
	// xo fields
	_exists, _deleted bool
}

// Exists returns true when the [Tag] exists in the database.
func (t *Tag) Exists() bool {
	return t._exists
}

// Deleted returns true when the [Tag] has been marked for deletion
// from the database.
func (t *Tag) Deleted() bool {
	return t._deleted
}

// Insert inserts the [Tag] to the database.
func (t *Tag) Inser
    
func (t *Tag) Insert(ctx context.Context, db DB) error {
	switch {
	case t._exists: // already exists
		return logerror(&ErrInsertFailed{ErrAlreadyExists})
	case t._deleted: // deleted
		return logerror(&ErrInsertFailed{ErrMarkedForDeletion})
	}
	// insert (primary key generated and returned by database)
	const sqlstr = `INSERT INTO django.tags (` +
		`tag` +
		`) VALUES (` +
		`?` +
		`)`
	// run
	logf(sqlstr, t.Tag)
	res, err := db.ExecContext(ctx, sqlstr, t.Tag)
	if err != nil {
		return logerror(err)
	}
	// retrieve id
	id, err := res.LastInsertId()
	if err != nil {
		return logerror(err)
	} // set primary key
	t.TagID = int64(id)
	// set exists
	t._exists = true
	return nil
}