try to put your sql_data array of arrays into another array like this

this.conn.query("...your query", [sql_data], (err) => {...})

so you match question mark in your statement, so if there was another one question mark, it would look like [sql_data, another_variable]

Too low on rep for comment, but I wanted to add a slightly more complex syntax that was inspired by @ʞɔıu response. To update multiple fields on duplicate key:

INSERT INTO t (t.a, t.b, t.c, t.d)
VALUES ('key1','key2','value','valueb'), ('key1','key3','value2','value2b')
ON DUPLICATE KEY UPDATE
t.c = VALUES(t.c),
t.d = VALUES(t.d)

I was confused by how to get this to work in a react/redux app and eventually came to the "correct" method.

My implementation required me to update one field value per record for an arbitrary number of records in a table with 21 fields.

If you are passing data as an array structure it like [['dataString',666.66],['dataString2',666666.66],['dataString3',666666666.66]] and then make sure you pass this whole thing as an array to the query function. See itemQtyData in my code sample below.

Another thing that tripped me up was the use of brackets around the values replacement string. I didn't need them. The examples I looked at showed implementations that needed them. I also only used a single ? for all the values. So instead of using (?,?) to represent the values in the query, which didn't work, I used ?.

I found it unnecessary to supply all the field names and the corresponding values for the table. MySQL will warn you if fields don't have a default value. I haven't found this to be an issue in this case.

You can console.log the formatted sql in SqlString.format function in the file node_modules/sqlstring/lib/SqlString.js. I found this useful to see exactly why the query wasn't working and to have something that I could plug into MySQL Workbench to mess around with.

Edit: You can also do this console.log(connection.query(yourQuery, [someData], callback)) and you get the sql and lot's more when the function executes. Might make more sense than adding console.log calls to the module code.

Hope this helps!

let itemQtyData = order.map(item => {
    return [
      `${item.id}`,
      `${Number(item.products_quantity - Number(item.quantity_to_add))}`
    ];
  });

const updateQtyQuery =`INSERT INTO products (products_id, products_quantity) VALUES ? ON DUPLICATE KEY UPDATE products_quantity=VALUES(products_quantity)`;

connectionOSC.query(
  updateQtyQuery,
  [itemQtyData],
  (error, results, fields) => {
    if (error) throw error;

    const response = {
      statusCode: 200,
      headers: {
        "Access-Control-Allow-Origin": "*"
      },
      body: saleId,
      response: results,
      isBase64Encoded: false
    };
context.succeed(response);
});

I was looking for the same behavior using jdbi's BindBeanList and found the syntax is exactly the same as Peter Lang's answer above. In case anybody is running into this question, here's my code:

  @SqlUpdate("INSERT INTO table_one (col_one, col_two) VALUES <beans> ON DUPLICATE KEY UPDATE col_one=VALUES(col_one), col_two=VALUES(col_two)")
void insertBeans(@BindBeanList(value = "beans", propertyNames = {"colOne", "colTwo"}) List<Beans> beans);

One key detail to note is that the propertyName you specify within @BindBeanList annotation is not same as the column name you pass into the VALUES() call on update.

Make sure the valuesArray is not empty as well! That was giving me a headache