node.js-连接SQLserver数据库

1.在自己的项目JS文件夹中建文件：config.js、mssql.js和server.js以及api文件夹下的user.js

2.在config.js中封装数据库信息

let app = {
  user: 'sa', //这里写你的数据库的用户名
  password: '',//这里写数据库的密码
  server: 'localhost',
  database: 'medicineSystem', // 数据库名字
  port: 1433, //端口号,默认1433
  options: {
    encrypt: false,  //加密,设置为true时会连接失败 Failed to connect to localhost:1433 - self signed certificate
    enableArithAbort: false
  },
  pool: {
    min: 0,
    max: 10,
    idleTimeoutMillis: 3000
  }
}

module.exports = app

3.在mssql.js中对sql语句的二次封装

//mssql.js
/**
 *sqlserver Model
 **/
const mssql = require("mssql");
const conf = require("./config.js");

const pool = new mssql.ConnectionPool(conf)
const poolConnect = pool.connect()

pool.on('error', err => {
  console.log('error: ', err)
})
/**
 * 自由查询
 * @param sql sql语句，例如: 'select * from news where id = @id'
 * @param params 参数，用来解释sql中的@*，例如： { id: id }
 * @param callBack 回调函数
 */
let querySql = async function (sql, params, callBack) {
  try {
    let ps = new mssql.PreparedStatement(await poolConnect);
    if (params != "") {
      for (let index in params) {
        if (typeof params[index] == "number") {
          ps.input(index, mssql.Int);
        } else if (typeof params[index] == "string") {
          ps.input(index, mssql.NVarChar);
        }
      }
    }
    ps.prepare(sql, function (err) {
      if (err)
        console.log(err);
      ps.execute(params, function (err, recordset) {
        callBack(err, recordset);
        ps.unprepare(function (err) {
          if (err)
            console.log(err);
        });
      });
    });
  } catch (e) {
    console.log(e)
  }
};

/**
 * 按条件和需求查询指定表
 * @param tableName 数据库表名，例：'news'
 * @param topNumber 只查询前几个数据，可为空，为空表示查询所有
 * @param whereSql 条件语句，例：'where id = @id'
 * @param params 参数，用来解释sql中的@*，例如： { id: id }
 * @param orderSql 排序语句，例：'order by created_date'
 * @param callBack 回调函数
 */
let select = async function (tableName, topNumber, whereSql, params, orderSql, callBack) {
  try {
    let ps = new mssql.PreparedStatement(await poolConnect);
    let sql = "select * from " + tableName + " ";
    if (topNumber != "") {
      sql = "select top(" + topNumber + ") * from " + tableName + " ";
    }
    sql += whereSql + " ";
    if (params != "") {
      for (let index in params) {
        if (typeof params[index] == "number") {
          ps.input(index, mssql.Int);
        } else if (typeof params[index] == "string") {
          ps.input(index, mssql.NVarChar);
        }
      }
    }
    sql += orderSql;
    console.log(sql);
    ps.prepare(sql, function (err) {
      if (err)
        console.log(err);
      ps.execute(params, function (err, recordset) {
        callBack(err, recordset);
        ps.unprepare(function (err) {
          if (err)
            console.log(err);
        });
      });
    });
  } catch (e) {
    console.log(e)
  }
};

/**
 * 查询指定表的所有数据
 * @param tableName 数据库表名
 * @param callBack 回调函数
 */
let selectAll = async function (tableName, callBack) {
  try {
    let ps = new mssql.PreparedStatement(await poolConnect);
    let sql = "select * from " + tableName + " ";
    ps.prepare(sql, function (err) {
      if (err)
        console.log(err);
      ps.execute("", function (err, recordset) {
        callBack(err, recordset);
        ps.unprepare(function (err) {
          if (err)
            console.log(err);
        });
      });
    });
  } catch (e) {
    console.log(e)
  }
};

/**
 * 添加字段到指定表
 * @param addObj 需要添加的对象字段，例：{ name: 'name', age: 20 }
 * @param tableName 数据库表名
 * @param callBack 回调函数
 */
let add = async function (addObj, tableName, callBack) {
  try {
    let ps = new mssql.PreparedStatement(await poolConnect);
    let sql = "insert into " + tableName + "(";
    if (addObj != "") {
      for (let index in addObj) {
        if (typeof addObj[index] == "number") {
          ps.input(index, mssql.Int);
        } else if (typeof addObj[index] == "string") {
          ps.input(index, mssql.NVarChar);
        }
        sql += index + ",";
      }
      sql = sql.substring(0, sql.length - 1) + ") values(";
      for (let index in addObj) {
        if (typeof addObj[index] == "number") {
          sql += addObj[index] + ",";
        } else if (typeof addObj[index] == "string") {
          sql += "'" + addObj[index] + "'" + ",";
        }
      }
    }
    sql = sql.substring(0, sql.length - 1) + ") SELECT @@IDENTITY id"; // 加上SELECT @@IDENTITY id才会返回id
    ps.prepare(sql, function (err) {
      if (err) console.log(err);
      ps.execute(addObj, function (err, recordset) {
        callBack(err, recordset);
        ps.unprepare(function (err) {
          if (err)
            console.log(err);
        });
      });
    });
  } catch (e) {
    console.log(e)
  }
};

/**
 * 更新指定表的数据
 * @param updateObj 需要更新的对象字段，例：{ name: 'name', age: 20 }
 * @param whereObj 需要更新的条件，例: { id: id }
 * @param tableName 数据库表名
 * @param callBack 回调函数
 */
let update = async function (updateObj, whereObj, tableName, callBack) {
  try {
    let ps = new mssql.PreparedStatement(await poolConnect);
    let sql = "update " + tableName + " set ";
    if (updateObj != "") {
      for (let index in updateObj) {
        if (typeof updateObj[index] == "number") {
          ps.input(index, mssql.Int);
          sql += index + "=" + updateObj[index] + ",";
        } else if (typeof updateObj[index] == "string") {
          ps.input(index, mssql.NVarChar);
          sql += index + "=" + "'" + updateObj[index] + "'" + ",";
        }
      }
    }
    sql = sql.substring(0, sql.length - 1) + " where ";
    if (whereObj != "") {
      for (let index in whereObj) {
        if (typeof whereObj[index] == "number") {
          ps.input(index, mssql.Int);
          sql += index + "=" + whereObj[index] + " and ";
        } else if (typeof whereObj[index] == "string") {
          ps.input(index, mssql.NVarChar);
          sql += index + "=" + "'" + whereObj[index] + "'" + " and ";
        }
      }
    }
    sql = sql.substring(0, sql.length - 5);
    ps.prepare(sql, function (err) {
      if (err)
        console.log(err);
      ps.execute(updateObj, function (err, recordset) {
        callBack(err, recordset);
        ps.unprepare(function (err) {
          if (err)
            console.log(err);
        });
      });
    });
  } catch (e) {
    console.log(e)
  }
};

/**
 * 删除指定表字段
 * @param whereSql 要删除字段的条件语句，例：'where id = @id'
 * @param params 参数，用来解释sql中的@*，例如： { id: id }
 * @param tableName 数据库表名
 * @param callBack 回调函数
 */
let del = async function (whereSql, params, tableName, callBack) {
  try {
    let ps = new mssql.PreparedStatement(await poolConnect);
    let sql = "delete from " + tableName + " ";
    if (params != "") {
      for (let index in params) {
        if (typeof params[index] == "number") {
          ps.input(index, mssql.Int);
        } else if (typeof params[index] == "string") {
          ps.input(index, mssql.NVarChar);
        }
      }
    }
    sql += whereSql;
    ps.prepare(sql, function (err) {
      if (err)
        console.log(err);
      ps.execute(params, function (err, recordset) {
        callBack(err, recordset);
        ps.unprepare(function (err) {
          if (err)
            console.log(err);
        });
      });
    });
  } catch (e) {
    console.log(e)
  }
};

exports.config = conf;
exports.del = del;
exports.select = select;
exports.update = update;
exports.querySql = querySql;
exports.selectAll = selectAll;
exports.add = add;

4.在api/user.js下写接口代码

//user.js
const express = require('express');
const db = require('../mssql.js');
const moment = require('moment');
const router = express.Router();

/* GET home page. */
router.get('/medicineList', function (req, res, next) {//查询某表下的全部数据
  db.selectAll('medicineList', function (err, result) {
    res.send(result.recordset)
  });
});
router.get('/medicineAssess', function (req, res, next) {
  db.selectAll('medicineAssess', function (err, result) {
    res.send(result.recordset)
  });
});
router.get('/medicineAsk', function (req, res, next) {
  db.selectAll('medicineAsk', function (err, result) {
    res.send(result.recordset)
  });
});
router.get('/diseaseList', function (req, res, next) {
  db.selectAll('diseaseList', function (err, result) {
    res.send(result.recordset)
  });
});
router.get('/diseaseMedicine', function (req, res, next) {
  db.selectAll('diseaseMedicine', function (err, result) {
    res.send(result.recordset)
  });
});
router.get('/user', function (req, res, next) {
  db.selectAll('user', function (err, result) {
    res.send(result.recordset)
  });
});
router.get('/admin', function (req, res, next) {
  db.selectAll('admin', function (err, result) {
    res.send(result.recordset)
  });
});
router.post('/delete', function (req, res, next) {//删除一条id对应的userInfo表的数据
  const { UserId } = req.body
  const id = UserId
  db.del("where id = @id", { id: id }, "userInfo", function (err, result) {
    console.log(result, 66);
    res.send('ok')
  });
});
router.post('/update/:id', function (req, res, next) {//更新一条对应id的userInfo表的数据
  var id = req.params.id;
  var content = req.body.content;
  db.update({ content: content }, { id: id }, "userInfo", function (err, result) {
    res.redirect('back');
  });
});

module.exports = router;

5.在server.js中配置启动文件

//1.导入模块
const express = require('express')

//2.创建服务器
let server = express()
server.use(express.urlencoded()) //中间件要写在启动文件里面

const cors = require('cors')
server.use(cors())

const user = require('./api/user.js')

server.use('/', user)

//3.开启服务器
server.listen(8002, () => {
  console.log('服务器已启动,在端口号8002')
})

6.启动服务器

cmd到server.js所在的目录下输入：

nodemon server.js

7.用postman测试接口