Node-postgres: Error on transaction: TypeError: this.callback is not a function

[ClueLessEggHead]

Hi, while trying to add data to the db via a transaction I keep getting a 'TypeError: this.callback is not a function'. It happens on ' /node_modules/pg/lib/query.js:142 return this.callback(err) '

This is the code I use:

//Create connection
const connectionString = 'postgres://localhost:5432/mm';

const pg = require('pg');
const client = new pg.Client(connectionString);
client.connect();
const { Pool, Client } = require('pg')
const pool = new Pool({
  connectionString: connectionString,
})

//Called from a function:

    (async () => {
        // note: we don't try/catch this because if connecting throws an exception
        // we don't need to dispose of the client (it will be undefined)
        const client = await pool.connect()  
          .then(() => {
            console.log('successful connection');
          })
          .catch((err) => {
            console.error('Error connecting: %s', err);
          });

        try {
          await client.query('BEGIN')

          for (var i = 0; i < csvarray.length - 1; i++)
          { 

            var y = i;
            const sqlstring = "INSERT INTO data (A, B, C, D, E, F, G, H, I) VALUES ($1, $2, $3, $4, $5, $6, $7, $8, $9);";
            await client.query(sqlstring, [csvarray[y][0],csvarray[y][1],csvarray[y][2],csvarray[y][3],csvarray[y][4],csvarray[y][5],csvarray[y][6],csvarray[y][7]],csvarray[y][8])
          }

          await client.query('COMMIT')
        } catch (e) {
          await client.query('ROLLBACK')
          throw e
        } finally {
          client.release()
        }
      })().catch(e => console.log(e.stack))

[sehrope]

You don't need .then() / .catch() with async / await. Plus awaiting the .then(...) will give you undefined as you're not returning the client:

        // note: we don't try/catch this because if connecting throws an exception
        // we don't need to dispose of the client (it will be undefined)
        const client = await pool.connect()  
          .then(() => {
            console.log('successful connection');
          })
          .catch((err) => {
            console.error('Error connecting: %s', err);
          });

The parameters for the query must be a single array. You're missing the wrapping [ ... ]:

            const sqlstring = "INSERT INTO data (A, B, C, D, E, F, G, H, I) VALUES ($1, $2, $3, $4, $5, $6, $7, $8, $9);";
            await client.query(sqlstring, [csvarray[y][0],csvarray[y][1],csvarray[y][2],csvarray[y][3],csvarray[y][4],csvarray[y][5],csvarray[y][6],csvarray[y][7]],csvarray[y][8])

Otherwise the client.query(...) will think that the second parameter (list of parameters) is [csvarray[y][0] and the third parameter (callback upon query completion or error) is csvarray[y][1].

[charmander]

Arguments are the problem, yep. Reformatted for clarity:

await client.query(
  sqlstring,
  [csvarray[y][0],csvarray[y][1],csvarray[y][2],csvarray[y][3],csvarray[y][4],csvarray[y][5],csvarray[y][6],csvarray[y][7]],
  csvarray[y][8]
)

csvarray[y][8] needs to be inside the parameter value array, not the third argument to client.query() (which is the callback). csvarray[y].slice(0, 9) might be appropriate?

(pg should be throwing synchronously as soon as you call client.query with the wrong types, though, instead of having a vague error that loses the stack trace. There’s an issue open for that somewhere.)

[ClueLessEggHead]

Can't believe I overlooked that.. thank you!