🔎 Example of Tedious SQL Server DB controller in Node.js (non-concurrent)

dbController.js

var Connection = require("tedious").Connection;
var Request = require("tedious").Request;
var ConnectionPool = require("tedious-connection-pool");

// Avoiding concurrent SQL SERVER calls
var poolConfig = {
  min: 1,
  max: 1,
  log: true
};

// Edit this config
var connectionConfig = {
  userName: "username",
  password: "password",
  server: "ipaddress",
  options: {
    rowCollectionOnDone: true, // Only get row set instead of row by row
    useColumnNames: true // For easier JSON formatting
  }
};

var _rows = [];

var pool = new ConnectionPool(poolConfig, connectionConfig);

pool.on("error", function(err) {
  console.error(err);
});

var _rows = [];

const query = (params, sql, callback) => {
  pool.acquire((err, connection) => {
    request = new Request(sql, (err, rowCount) => {
      if (err) {
        console.log(err);
        return;
      }
      connection.release();
    });

    if (params.length > 0) {
      params.forEach(param => {
        request.addParameter(param.name, param.type, param.value);
      });
    }

    _rows = [];

    request.on("row", columns => {
      var _item = {};
      // Converting the response row to a JSON formatted object: [property]: value
      for (var name in columns) {
        _item[name] = columns[name].value;
      }
      _rows.push(_item);
    });

    // We return the set of rows after the query is complete, instead of returing row by row
    request.on("doneInProc", (rowCount, more, rows) => {
      callback(_rows);
    });

    connection.execSql(request);
  });
};

const proc = (params, sql, callback) => {
  pool.acquire((err, connection) => {
    request = new Request(sql, (err, rowCount) => {
      if (err) {
        console.log(err);
        return;
      }
      connection.release();
    });

    if (params.length > 0) {
      params.forEach(param => {
        request.addParameter(param.name, param.type, param.value);
      });
    }

    _rows = [];

    request.on("row", columns => {
      var _item = {};
      // Converting the response row to a JSON formatted object: [property]: value
      for (var name in columns) {
        _item[name] = columns[name].value;
      }
      _rows.push(_item);
    });

    // We return the set of rows after the procedure is complete, instead of returing row by row
    request.on("doneProc", (rowCount, more, rows) => {
      callback(_rows);
    });

    connection.callProcedure(request);
  });
};

const buildParams = (params, name, type, value) => {
  params.push({
    name: name,
    type: type,
    value: value
  });
};

module.exports = {
  buildParams: buildParams,
  query: query,
  proc: proc
};

exampleTedious.js

var db = require("./dbController.js");
var TYPES = require("tedious").TYPES;

// QUERY
// Imagine we have a table called pokemon with 2 attributes: name and number
// We want to find a pokemon by number, using a select query
const getPokemon = (number) => {
  var params = [];
  var sql = "select * from pokemon where number = @number";
  // For each param do: db.buildParams(params, "name", TYPES.type, variable)
  db.buildParams(params, "number", TYPES.Int, number);
  db.query(params, sql, result => {
    console.log(result);
  });
}

// PROCEDURE
// The same as above but using instead a procedure called findPokemon(number)
const getPokemonProc = (number) => {
  var params = [];
  var sql = "findPokemon"; // instead of query selector use only procedure name
  // For each param do: db.buildParams(params, "name", TYPES.type, variable)
  db.buildParams(params, "number", TYPES.Int, number); // Params will be added automatically to the procedure exec
  db.proc(params, sql, result => { // Just need to change from query to proc
    console.log(result);
  });
}


getPokemon(132);
getPokemonProc(34);

module.exports = {
  getPokemon: getPokemon,
  getPokemonProc: getPokemonProc
}

How I do for return the values to controller, from the model?

Hi man, could you take some time to help me?
I´ve implemented something similar but i always get this error, this happend at the execSql method:
TypeError: cb is not a function
at Object.writeParameterData

maybe if you have interest to help
i would show you my code, Thanks in advanced

private getLocations(argUrlParams?: object | undefined): Promise<any[]> {

    console.log(" get Locations from DB");
    const TYPES = tedious.TYPES;
    let queryText = queries.locations;
    const Request = tedious.Request;
    // Read all rows from table

    queryText = queries.locations.replace(`%ConditionalInnerJoin%`, "");
    queryText = queryText.replace(`%ConditionalWhere%`, "");

    const parameters: any[] = [];

    parameters.push(
      {
        name: "accountId",
        type: TYPES.Int,
        value: Object.values(argUrlParams)[0]
      });
    parameters.push(
      {
        name: "companyNumber",
        type: TYPES.Int,
        value: Object.values(argUrlParams)[1]
      });

    return new Promise<any[]>((resolve) => {
      this.readTable(queryText, parameters, (result) => {
        resolve(result);
      })
    })
  }


  private readTable(argQueryText: string, argParameters: any[], argCallBack: (n: any[]) => any): any[] {
    // Attempt to connect and execute queries if connection goes through
    const TYPES = tedious.TYPES;
    const jsonArray: any[] = [];

    console.log("-1");
    // tslint:disable-next-line: no-shadowed-variable
    this.pool.acquire((err, connection) => {
      console.log("0");
      if (err) {
        console.log(err);
        argCallBack(jsonArray);
      }

      console.log("===SQLConnectionManager 🔌 Establishing connection===");

      try {

        const request = new tedious.Request(argQueryText, (error, rowCount) => {
          if (error) {
            console.log('a jijo');

            console.log(error);
            return;
          }
          console.log(rowCount + " row(s) returned");
          connection.release();
        });

        if (argParameters.length > 0) {
          argParameters.forEach(param => {
            request.addParameter(param.name, param.type, param.value);
          });
        }

        console.log("1");
        request.on("row", (columns: any) => {
          const rowObject: any = {};
          //  console.log('2');
          columns.forEach((column: any) => {
            rowObject[column.metadata.colName] = column.value;
          });
          jsonArray.push(rowObject);
        });

        console.log("3");

        request.on("doneInProc", (rowCount, more, rows) => {
          console.log("5");
          return argCallBack(jsonArray);;
        });

        connection.execSql(request);
        console.log("4");
      } catch (error) {
        console.log('error en el catch');
        console.log(error);
        connection.release();
        argCallBack(jsonArray);
      }

    })

    return jsonArray;
  }

replace type.writeParameterData(buffer, param, options);
with: type.writeParameterData(buffer, param, options, ()=>{});
"at new RpcRequestPayload (D:\Projects\Statistics\node_modules\tedious-connection-pool\node_modules\tedious\lib\rpcrequest-payload.js:95:12)"

yes, thanks i solved this exactly like that, but you know this problem will occur every time a new npm install its executed

Why you suggest avoid concurrent SQL calls ?