Inserting multiple rows into SQL Server from Node.js

Question

I am working on a project that will upload some records to SQL Server from a node.js program. Right now, this is my approach (inside an async function):

con = await sql.connect(`mssql://${SQL.user}:${SQL.password}@${SQL.server}/${SQL.database}?encrypt=true`);
for (r of RECORDS) {
        columns = `([column1], [column2], [column3])`;
        values = `(@col1, @col2, @col3)`;
        await con
            .request()
            .input("col1", sql.Int, r.col1)
            .input("col2", sql.VarChar, r.col2)
            .input("col3", sql.VarChar, r.col3)
            .query(`INSERT INTO [dbo].[table1] ${columns} VALUES ${values}`);
}

Where records is an array of objects in the form:

RECORDS = [
    { col1: 1, col2: "asd", col3: "A" },
    { col1: 2, col2: "qwerty", col3: "B" },
    // ...
];

This code works, nevertheless, I have the feeling that it is not efficient at all. I have an upload of around 4k records and it takes roughly 10 minutes, it does not look good.

I believe if I can create a single query - instead of wrapping single inserts inside a for loop - with all the record values it will be faster, and I know there is a syntax for reaching that in SQL:

INSERT INTO table1 (column1, column2, column3) VALUES (1, "asd", "A"), (2, "qwerty", "B"), (...);

However I cannot find any documentation from mssql module for node on how to prepare the parameterized inputs to do everything in a single transaction.

Can anyone guide me into the right direction?

Thanks in advance.

use bull insert. https://stackoverflow.com/questions/43663017/bulk-inserting-with-node-mssql-package — Joaquín, Jul 20 '20 at 12:56
Ok I've tried following the link you sent me but I am getting some errors. There is one complexity with the `VarChar(max)` fields which I think is sorted out with `{length: infinity}` and yet I have some column type error. Let me give it more time and get back to you — Jorge Valentini, Jul 20 '20 at 14:45
Nevermind, it was my bad, this one did the trick, thank you Joaquin — Jorge Valentini, Jul 20 '20 at 15:11

score 3 · Answer 1 · answered Jul 20 '20 at 17:16

Also, very similar to the bulk insert, you can use a table valued parameter.

sql.connect("mssql://${SQL.user}:${SQL.password}@${SQL.server}/${SQL.database}?encrypt=true")
  .then(() => {
    const table = new sql.Table();
    table.columns.add('col1', sql.Int);
    table.columns.add('col2', sql.VarChar(20));
    table.columns.add('col3', sql.VarChar(20));

    // add data
    table.rows.add(1, 'asd', 'A');
    table.rows.add(2, 'qwerty', 'B');

    const request = new sql.Request();
    request.input('table1', table);  

    request.execute('procMyProcedure', function (err, recordsets, returnValue) {  
       console.dir(JSON.stringify(recordsets[0][0]));  
       res.end(JSON.stringify(recordsets[0][0]));  
    });  
  });

And then for the SQL side, create a user defined table type

CREATE TYPE typeMyType AS TABLE
(
   Col1 int,
   Col2 varchar(20),
   Col3 varchar(20)
)

And then use this in the stored procedure

CREATE PROCEDURE procMyProcedure
   @table1 typeMyType READONLY
AS
BEGIN
   INSERT INTO table1 (Col1, Col2, Col3)
   SELECT Col1, Col2, Col3
   FROM @MyRecords
END

This gives you more control over the data and lets you do more with the data in sql before you actually insert.

Thanks for the reply, I went for Joaquin's approach but I upvoted your answer! Thanks! — Jorge Valentini, Jul 20 '20 at 17:23

score 2 · Accepted Answer · answered Jul 20 '20 at 17:22

As pointed out by @JoaquinAlvarez, bulk insert should be used as replied here: Bulk inserting with Node mssql package

For my case, the code was like:

return await sql.connect(`mssql://${SQL.user}:${SQL.password}@${SQL.server}/${SQL.database}?encrypt=true`).then(() => {
    table = new sql.Table("table1");
    table.create = true;
    table.columns.add("column1", sql.Int, { nullable: false });
    table.columns.add("column2", sql.VarChar, { length: Infinity, nullable: true });
    table.columns.add("column3", sql.VarChar(250), { nullable: true });

    // add here rows to insert into the table
    for (r of RECORDS) {
        table.rows.add(r.col1, r.col2, r.col3);
    }

    return new sql.Request().bulk(table);
});

The SQL data types have to match (obviously) the column type of the existing table table1. Note the case of column2, which is a column defined in SQL as varchar(max).

Thanks Joaquin! I went down on the time significantly from 10 minutes to a few seconds

Inserting multiple rows into SQL Server from Node.js

2 Answers2