修复 SQL 错误不兼容类型：capture#1 of? 无法转换为 int

Question

I have a SQL query to query an Ignite cache database. But select count(column_Name) gives following compilation error. incompatible types: capture#1 of? cannot be converted to int

here is my code.

private static final String sql = "Select count(_val) from Annotations where  orderId = ? and timestamp <= ? and timestamp >= ? ";
SqlFieldsQuery sqlQ = new SqlFieldsQuery(sql).setArgs(id, t1, t2);
int count = 0;
        try (QueryCursor<List<?>> cursor = cache.query(sqlQ)) {
            for (List<?> row : cursor) {
                
                    count = (int) row.get(0);
                
            }

Instead of the for loop, I tried count = (int) cursor.getAll().get(0).get(0); But that also didn't work. Anyone have an idea what's happening here. Thank You.

Answer 1

Have you tried replacing ? with actual type?

    try (QueryCursor<List<Integer>> cursor = cache.query(sqlQ)) {
        for (List<Integer> row : cursor)                
                count = row.get(0);
            
    }