count_if
count_if介绍
count_if(expr) - 返回表达式中 TRUE 值的数量。
Examples:
> SELECT count_if(col % 2 = 0) FROM VALUES (NULL), (0), (1), (2), (3) AS tab(col);
2
> SELECT count_if(col IS NULL) FROM VALUES (NULL), (0), (1), (2), (3) AS tab(col);
1
Since: 3.0.0