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: query_history_mig.go
    path of file: ./repos/grafana/pkg/services/sqlstore/migrations
    
    the code of the file until where you have to start completion: package migrations

import (
	. "github.com/grafana/grafana/pkg/services/sqlstore/migrator"
)

func addQueryHistoryMigrations(mg *Migrator) {
	queryHistoryV1 := Table{
		Name: "query_history",
		Columns: []*Column{
			{Name: "id", Type: DB_BigInt, Nullable: false, IsPrimaryKey: true, IsAutoIncrement: true},
			{Name: "uid", Type: DB_NVarchar, Length: 40, Nullable: false},
			{Name: "org_id", Type: DB_BigInt, Nullable: false},
			{Name: "datasource_uid", Type: DB_NVarchar, Length: 40, Nullable: false},
			{Name: "created_by", Type: DB_Int, Nullable: false},
			{Name: "created_at", Type: DB_Int, Nullable: false},
			{Name: "comment", Type: DB_Text, Nullable: false},
			{Name: "queries", Type: DB_Text, Nullable: false},
    
func addQueryHistoryMigrations(mg *Migrator) {
	queryHistoryV1 := Table{
		Name: "query_history",
		Columns: []*Column{
			{Name: "id", Type: DB_BigInt, Nullable: false, IsPrimaryKey: true, IsAutoIncrement: true},
			{Name: "uid", Type: DB_NVarchar, Length: 40, Nullable: false},
			{Name: "org_id", Type: DB_BigInt, Nullable: false},
			{Name: "datasource_uid", Type: DB_NVarchar, Length: 40, Nullable: false},
			{Name: "created_by", Type: DB_Int, Nullable: false},
			{Name: "created_at", Type: DB_Int, Nullable: false},
			{Name: "comment", Type: DB_Text, Nullable: false},
			{Name: "queries", Type: DB_Text, Nullable: false},
		},
		Indices: []*Index{
			{Cols: []string{"org_id", "created_by", "datasource_uid"}},
		},
	}

	mg.AddMigration("create query_history table v1", NewAddTableMigration(queryHistoryV1))

	mg.AddMigration("add index query_history.org_id-created_by-datasource_uid", NewAddIndexMigration(queryHistoryV1, queryHistoryV1.Indices[0]))

	mg.AddMigration("alter table query_history alter column created_by type to bigint", NewRawSQLMigration("").
		Mysql("ALTER TABLE query_history MODIFY created_by BIGINT;").
		Postgres("ALTER TABLE query_history ALTER COLUMN created_by TYPE BIGINT;"))
}