exports.up = knex => {
return knex.schema
.alterTable('pageHistory', table => {
table.string('versionDate').notNullable().defaultTo('')
})
.raw(`UPDATE pageHistory AS h1 SET versionDate = COALESCE((SELECT createdAt FROM pageHistory AS h2 WHERE h2.pageId = h1.pageId AND h2.id < h1.id ORDER BY h2.id DESC LIMIT 1), h1.createdAt, '')`)
}
exports.down = knex => { }