说明
If 组合器可应用于 sum
函数，借助 sumIf 聚合组合器函数
计算条件为真的行中各值的总和。
示例用法
sumIf 计算成功交易的销售总额。
Query
CREATE TABLE sales(
transaction_id UInt32,
amount Decimal(10,2),
is_successful UInt8
) ENGINE = MergeTree
ORDER BY ();
INSERT INTO sales VALUES
(1, 100.50, 1),
(2, 200.75, 1),
(3, 150.25, 0),
(4, 300.00, 1),
(5, 250.50, 0),
(6, 175.25, 1);
SELECT
sumIf(amount, is_successful = 1) AS total_successful_sales
FROM sales;
sumIf 函数只会对 is_successful = 1 的金额进行求和。
在这种情况下，求和结果为：100.50 + 200.75 + 300.00 + 175.25。
Response
┌─total_successful_sales─┐
1. │ 776.50 │
└───────────────────────┘
按价格变动方向计算交易量
stock 表，
计算 2002 年上半年按价格变动方向划分的交易量。
Query
SELECT
toStartOfMonth(date) AS month,
formatReadableQuantity(sumIf(volume, price > open)) AS volume_on_up_days,
formatReadableQuantity(sumIf(volume, price < open)) AS volume_on_down_days,
formatReadableQuantity(sumIf(volume, price = open)) AS volume_on_neutral_days,
formatReadableQuantity(sum(volume)) AS total_volume
FROM stock.stock
WHERE date BETWEEN '2002-01-01' AND '2002-12-31'
GROUP BY month
ORDER BY month;
┌──────month─┬─volume_on_up_days─┬─volume_on_down_days─┬─volume_on_neutral_days─┬─total_volume──┐
1. │ 2002-01-01 │ 26.07 billion │ 30.74 billion │ 781.80 million │ 57.59 billion │
2. │ 2002-02-01 │ 20.84 billion │ 29.60 billion │ 642.36 million │ 51.09 billion │
3. │ 2002-03-01 │ 28.81 billion │ 23.57 billion │ 762.60 million │ 53.14 billion │
4. │ 2002-04-01 │ 24.72 billion │ 30.99 billion │ 763.92 million │ 56.47 billion │
5. │ 2002-05-01 │ 25.09 billion │ 30.57 billion │ 858.57 million │ 56.52 billion │
6. │ 2002-06-01 │ 29.10 billion │ 30.88 billion │ 875.71 million │ 60.86 billion │
7. │ 2002-07-01 │ 32.27 billion │ 41.73 billion │ 747.32 million │ 74.75 billion │
8. │ 2002-08-01 │ 28.57 billion │ 27.49 billion │ 1.17 billion │ 57.24 billion │
9. │ 2002-09-01 │ 23.37 billion │ 31.02 billion │ 775.66 million │ 55.17 billion │
10. │ 2002-10-01 │ 38.57 billion │ 34.05 billion │ 956.48 million │ 73.57 billion │
11. │ 2002-11-01 │ 34.90 billion │ 25.47 billion │ 998.34 million │ 61.37 billion │
12. │ 2002-12-01 │ 22.99 billion │ 28.65 billion │ 1.14 billion │ 52.79 billion │
└────────────┴───────────────────┴─────────────────────┴────────────────────────┴───────────────┘
按股票代码计算交易量
stock 表，
计算 2006 年当时三家 крупнейших科技公司的按股票代码统计的交易量。
Query
SELECT
toStartOfMonth(date) AS month,
formatReadableQuantity(sumIf(volume, symbol = 'AAPL')) AS apple_volume,
formatReadableQuantity(sumIf(volume, symbol = 'MSFT')) AS microsoft_volume,
formatReadableQuantity(sumIf(volume, symbol = 'GOOG')) AS google_volume,
sum(volume) AS total_volume,
round(sumIf(volume, symbol IN ('AAPL', 'MSFT', 'GOOG')) / sum(volume) * 100, 2) AS major_tech_percentage
FROM stock.stock
WHERE date BETWEEN '2006-01-01' AND '2006-12-31'
GROUP BY month
ORDER BY month;
Response
┌──────month─┬─apple_volume───┬─microsoft_volume─┬─google_volume──┬─total_volume─┬─major_tech_percentage─┐
1. │ 2006-01-01 │ 782.21 million │ 1.39 billion │ 299.69 million │ 84343937700 │ 2.93 │
2. │ 2006-02-01 │ 670.38 million │ 1.05 billion │ 297.65 million │ 73524748600 │ 2.74 │
3. │ 2006-03-01 │ 744.85 million │ 1.39 billion │ 288.36 million │ 87960830800 │ 2.75 │
4. │ 2006-04-01 │ 718.97 million │ 1.45 billion │ 185.65 million │ 78031719800 │ 3.02 │
5. │ 2006-05-01 │ 557.89 million │ 2.32 billion │ 174.94 million │ 97096584100 │ 3.14 │
6. │ 2006-06-01 │ 641.48 million │ 1.98 billion │ 142.55 million │ 96304086800 │ 2.87 │
7. │ 2006-07-01 │ 624.93 million │ 1.33 billion │ 127.74 million │ 79940921800 │ 2.61 │
8. │ 2006-08-01 │ 639.35 million │ 1.13 billion │ 107.16 million │ 84251753200 │ 2.23 │
9. │ 2006-09-01 │ 633.45 million │ 1.10 billion │ 121.72 million │ 82775234300 │ 2.24 │
10. │ 2006-10-01 │ 514.82 million │ 1.29 billion │ 158.90 million │ 93406712600 │ 2.1 │
11. │ 2006-11-01 │ 494.37 million │ 1.24 billion │ 118.49 million │ 90177365500 │ 2.06 │
12. │ 2006-12-01 │ 603.95 million │ 1.14 billion │ 91.77 million │ 80499584100 │ 2.28 │
└────────────┴────────────────┴──────────────────┴────────────────┴──────────────┴───────────────────────┘