# mysql.batch

## Function

Set the number of rows per batch for batch exec.

## Syntax

```bt
mysql(dsn).query(sql).batch(size)
```

## Parameters

| Parameters | Type | Required | Default value | Description |
| ------ | ------ | ------ | ------ | ------ |
| size | Int | No | 0 | Batch size; values less than 0 are treated as 0. |

## Return value

| Type | Description |
| ------ | ------ |
| Mysql | Returns the new MySQL query builder. |

## Example

```bt
rows = [['A'], ['B'], ['C']]
db = mysql('mysql://user:pass@127.0.0.1/test')
result = db.query('insert into user(name) values (?)').binds(rows).batch(2).sql()

// Output: insert into user(name) values ('A'), ('B') /* binds: 3 rows, batch: 2, workers: 1 */
print result
```

## Notes

- batch(0) means that all rows will be used for INSERT batch preview and optimization; non-INSERT execution will be processed in batches of 1 row.