import csv

max_lengths = {
    'field1': 255,
    'field2': 1024,
    # add fields and their max sizes
}

def truncate_row(row):
    for field, max_len in max_lengths.items():
        if field in row and len(row[field]) > max_len:
            row[field] = row[field][:max_len]
    return row

with open('data.csv', newline='', encoding='utf-8') as csvfile:
    reader = csv.DictReader(csvfile)
    rows = []
    for row in reader:
        truncated_row = truncate_row(row)
        rows.append(truncated_row)
        # Insert truncated_row into SQL DB safely here

Select all