COUNT_IF (Lakehouse v1)

后缀 _IF 可以附加到任何聚合函数的名称之后。此时，聚合函数会接受一个额外的参数，即条件。

Analyze 语法

func.count_if(<column>, <cond>)

Analyze 示例

func.count_if(table.status, table.status=='Completed').alias('completed_orders')

| completed_orders |
|------------------|
|        3         |

SQL 示例

COUNT_IF(<column>, <cond>)

SQL 示例

创建表并插入示例数据

CREATE TABLE orders (
  id INT,
  customer_id INT,
  status VARCHAR,
  total FLOAT
);

INSERT INTO orders (id, customer_id, status, total)
VALUES (1, 1, 'completed', 100),
       (2, 2, 'completed', 200),
       (3, 1, 'pending', 150),
       (4, 3, 'completed', 250),
       (5, 2, 'pending', 300);

查询演示：统计已完成的订单

SELECT COUNT_IF(status, status = 'completed') AS completed_orders
FROM orders;

结果

| completed_orders |
|------------------|
|        3         |