node-postgresql/config/conn.js at master · usecodelee/node-postgresql · GitHub

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var pg = require('pg');
var conString = "postgres://postgres:密码@localhost/数据库名";
var client = new pg.Client(conString);

var PG = function() {
    console.log("准备向first_test连接...");
}

PG.prototype.getConnection = function() {
    client.connect(function(err) {
        if (err) {
            return console.error('could not connect to postgres', err);
        }
        client.query('SELECT NOW() AS "theTime"', function(err, result) {
            if (err) {
                return console.error('error running query', err);
            }
            console.log("first_test数据库连接成功...");
        });
    });
};

// 查询函数
//@param str 查询语句
//@param value 相关值
//@param cb 回调函数
var clientHelper = function(str, value, cb) {
        client.query(str, value, function(err, result) {
            if (err) {
                console.log(err);
                cb("err");
            } else {
                if (result.rows != undefined)
                    cb(result.rows);
                else
                    cb();
            }
        });
    }
    //增
    //@param tablename 数据表名称
    //@param fields 更新的字段和值，json格式
    //@param cb 回调函数
PG.prototype.save = function(tablename, fields, cb) {
    if (!tablename) return;
    var str = "insert into " + tablename + "(";
    var field = [];
    var value = [];
    var num = [];
    var count = 0;
    for (var i in fields) {
        count++;
        field.push(i);
        value.push(fields[i]);
        num.push("$" + count);
    }
    str += field.join(",") + ") values(" + num.join(",") + ")";
    clientHelper(str, value, cb);
};

//删除
//@param tablename 数据表名称
//@param fields 条件字段和值，json格式
//@param cb 回调函数
PG.prototype.remove = function(tablename, fields, cb) {
    if (!tablename) return;
    var str = "delete from " + tablename + " where ";
    var field = [];
    var value = [];
    var count = 0;
    for (var i in fields) {
        count++;
        field.push(i + "=$" + count);
        value.push(fields[i]);
    }
    str += field.join(" and ");
    clientHelper(str, value, cb);
}

//修改
//@param tablename 数据表名称
//@param fields 更新的字段和值，json格式
//@param mainfields 条件字段和值，json格式
PG.prototype.update = function(tablename, mainfields, fields, cb) {
    if (!tablename) return;
    var str = "update " + tablename + " set ";
    var field = [];
    var value = [];
    var count = 0;
    for (var i in fields) {
        count++;
        field.push(i + "=$" + count);
        value.push(fields[i]);
    }
    str += field.join(",") + " where ";
    field = [];
    for (var j in mainfields) {
        count++;
        field.push(j + "=$" + count);
        value.push(mainfields[j]);
    }
    str += field.join(" and ");
    clientHelper(str, value, cb);
}

//查询
//@param tablename 数据表名称
//@param fields 条件字段和值，json格式
//@param returnfields 返回字段
//@param cb 回调函数
PG.prototype.select = function(tablename, fields, returnfields, cb) {
    if (!tablename) return;
    var returnStr = "";
    if (returnfields.length == 0)
        returnStr = '*';
    else
        returnStr = returnfields.join(",");
    var str = "select " + returnStr + " from " + tablename + " where ";
    var field = [];
    var value = [];
    var count = 0;
    for (var i in fields) {
        count++;
        field.push(i + "=$" + count);
        value.push(fields[i]);
    }
    str += field.join(" and ");
    clientHelper(str, value, cb);
};

module.exports = new PG();