How can I use a variable as the table name in node-pg?

Question

For example I have a query like:

      const rows = await db.query(
        "SELECT * FROM $1 WHERE email = $2 AND password = $3",
        [tableName, email, password]
      );

It gives me a syntax error.

Answer 1

This is not possible, parameterised queries only work for values (instead of literals) but not for identifiers. You will need to build the SQL string:

const rows = await db.query(
  `SELECT * FROM ${db.escapeIdentifier(tableName)} WHERE email = $1 AND password = $2`,
  [email, password]
);

^{(Assuming the db is a PgClient)}

If you know the possible values of the tableName variable beforehand, you might get away without escaping; if you don't, you better also specify the schema explicitly.