nodejs sqlite 数据库操作

/** * Created by Administrator on 2016/5/11. */var fs = require("fs");var file = "test.db";var exists = fs.existsSync(file);var sqlite3 = require("sqlite3").verbose();var db = new sqlite3.Database(file);  //connect to our file/databasevar table_name="student"  //创建一张表，名字是studentdb.serialize(function() {  //serialize   call.    //creat a table student    db.run("CREATE TABLE IF NOT EXISTS  "+table_name+"  (" +        "sid  TEXT PRIMARY KEY NOT NULL," +     //字段        "name  TEXT    ," +                     //字段        "sex   INTEGER ," +                     //字段        "age   INTEGER  " +                     //字段        ") ");//数据库对象的run函数可以执行任何的SQL语句，该函数一般不用来执行查询    var insert = db.prepare("INSERT OR REPLACE  INTO "+table_name+"(sid,name) VALUES (?,?)"); //插入或者替换数据，    for (var i = 0; i < 10; i++) {        insert.run( i, "stu"+i);   //insert some data.    }    insert.finalize();     //operater finish    //删除一条数据：    var  del=db.prepare("DELETE from "+table_name+" where sid=?")    del.run(4)    del.finalize();    //修改一条数据：    var modify=db.prepare("UPDATE "+table_name+" set name=? where sid =?")    modify.run("bolin",5)    modify.finalize();    //数据库查询    db.each("SELECT rowid AS id, sid,name FROM "+table_name+"", function(err, row) {        console.log(row.id + ": " + row.sid+"  "+row.name);    });});db.close(); //closeconsole.log("end")