edu-textbook/server/db/pg-instance.js

const pgp = require('pg-promise')();

// 连接到数据库
var PgInstanse;
const pgClient = function(){
    if(!PgInstanse){
        PgInstanse = pgp({
            user: 'postgres',
            password: 'postgres',
            host: 'localhost',
            port: 25432,
            database: 'postgres'
        });
    }
    return PgInstanse;
}
module.exports.pgClient = pgClient