Error on bulk insert with execute()

When I try to insert multiple rows with a bulk insert and use the execute() method I get the error:

Error: You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near '?' at line 1

It works, when I use the query() method.

This is the interesting part of my code:

const con = await getConnection()
await con.beginTransaction()

const values = [name, comments, levelId, constructionId, id]
const sql = "UPDATE structures SET name = ?, comments = ?, level = ?, construction_id = ? WHERE structure_id = ?;"
await con.execute(sql, values)

const sql2 = "INSERT IGNORE INTO structure_categories (structure_id, category_id) VALUES ?;"
const values2 = categoryIds.map(categoryId => {
    return [id, categoryId]
})
await con.execute(sql2, [values2])

await con.commit()
await con.end()

Seems like the replacement of the ? on bulk inserts doesn’t work properly with the execute() method.

[sidorares]

your query ( including “?” symbols ) must be a valid input for PREPARE command, which is likely isn’t

also number of placeholders should be exactly the same as number of parameters. Few options here:

• just use .query() - that would interpolate parameters on the driver side and send long sql query with all the data in it
• dynamically insert a bunch of placeholders ( new Array(10).fill('?').join(',') ) to match the number of parameters. That way you’ll have statement prepared each time number is different but reused for same number of parameters, and you also benefit from separate processing of query and data which is potentially safer from sql injection point of view
• create a stored procedure that accepts array as JSON object and can iterate all elements in it and insert data server side: conn.execute('CALL sp_bulk_insert(?)', [JSON.stringify(data)])

[sidorares]

also LOAD DATA INFILE might have slightly better performance as you send your data as csv. You can pass the content of the file with the query, doesn’t have to be “real” file - see https://github.com/sidorares/node-mysql2/blob/master/documentation/Extras.md#sending-tabular-data-with-load-infile-and-local-stream

https://stackoverflow.com/questions/51673896/load-data-infile-and-spatial-data might be helpful