今天小編就爲大家分享一篇Nodejs對postgresql基本操作的封裝方法,具有很好的參考價值,希望對大家有所幫助。一起跟隨小編過來看看吧
基於nodejs平臺對postgresql的增刪改查基本操作進行了封裝,能滿足基本的實際應用,比較複雜的SQL需另外實現。
PG.js文件如下:
var pg = require('pg'); var conString = "postgres://username:password@localhost/databasename"; var client = new pg.Client(conString); var PG = function(){ console.log("準備向****數據庫連接..."); }; 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("hbdfxt數據庫連接成功..."); }); }); }; // 查詢函數 //@param str 查詢語句 //@param value 相關值 //@param cb 回調函數 var clientHelper = function(str,value,cb){ client.query(str,value,function(err,result){ if(err) { cb("err"); } else{ if(result.rows != undefined) cb(result.rows); else cb(); } }); } //增 //@param tablename 數據表名稱 //@param fields 更新的字段和值,json格式 //@param cb 回調函數 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("$"+count); } str += field.join(",") +") values("+num.join(",")+")"; clientHelper(str,value,cb); }; //刪除 //@param tablename 數據表名稱 //@param fields 條件字段和值,json格式 //@param cb 回調函數 PG.prototype.remove = function(tablename,fields,cb){ if(!tablename) return; var str = "delete from "+tablename+" where "; var field = []; var value = []; var count = 0; for(var i in fields){ count++; field.push(i+"=$" +count); value.push(fields[i]); } str += field.join(" and "); clientHelper(str,value,cb); } //修改 //@param tablename 數據表名稱 //@param fields 更新的字段和值,json格式 //@param mainfields 條件字段和值,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); } //查詢 //@param tablename 數據表名稱 //@param fields 條件字段和值,json格式 //@param returnfields 返回字段 //@param cb 回調函數 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();
用法很簡單,如下:
var pgclient = require('./PG');// 引用上述文件 pgclient.getConnection(); // 調用上述四個函數即可 pgclient.save('userinfo',{'name': admin},cb);<span style="font-family: Arial, Helvetica, sans-serif;">.</span>
以上這篇Nodejs對postgresql基本操作的封裝方法就是小編分享給大家的全部內容了,希望能給大家一個參考,也希望大家多多支持神馬文庫。