这是我在MySQL中使用的示例。但是，在BigQuery中，我的OnSite timestamp是 DATE ，而我的Documents时间戳是 TIMESTAMP 。
BigQuery遇到以下查询时遇到问题，因为我收到了消息：
对于参数类型DATE，函数DATE没有匹配的签名。支持的签名：DATE（TIMESTAMP，[STRING]）; DATE（DATETIME）; DATE（INT64，INT64，INT64）在[8：146]
有人知道我需要做什么才能使查询与DATE和TIMESTAMP进行比较吗？
模式（MySQL v5.7）
CREATE TABLE OnSite
(`uid` varchar(55), `worksite_id` varchar(55), `timestamp` datetime)
;
INSERT INTO OnSite
(`uid`, `worksite_id`, `timestamp`)
VALUES
("u12345", "worksite_1", '2019-01-01'),
("u12345", "worksite_1", '2019-01-02'),
("u12345", "worksite_1", '2019-01-03'),
("u12345", "worksite_1", '2019-01-04'),
("u12345", "worksite_1", '2019-01-05'),
("u12345", "worksite_1", '2019-01-06'),
("u1", "worksite_1", '2019-01-01'),
("u1", "worksite_1", '2019-01-02'),
("u1", "worksite_1", '2019-01-05'),
("u1", "worksite_1", '2019-01-06')
;
CREATE TABLE Documents
(`document_id` varchar(55), `uid` varchar(55), `worksite_id` varchar(55), `type` varchar(55), `timestamp` datetime)
;
INSERT INTO Documents
(`document_id`, `uid`, `worksite_id`, `type`, `timestamp`)
VALUES
("1", "u12345", "worksite_1", 'work_permit', '2019-01-01 00:00:00'),
("2", "u12345", "worksite_2", 'job', '2019-01-02 00:00:00'),
("3", "u12345", "worksite_1", 'work_permit', '2019-01-03 00:00:00'),
("4", "u12345", "worksite_2", 'job', '2019-01-04 00:00:00'),
("5", "u12345", "worksite_1", 'work_permit', '2019-01-05 00:00:00'),
("6", "u12345", "worksite_2", 'job', '2019-01-06 00:00:00'),
("7", "u12345", "worksite_1", 'work_permit', '2019-01-07 00:00:00'),
("8", "u12345", "worksite_2", 'work_permit', '2019-01-09 00:00:00'),
("9", "u12345", "worksite_1", 'job', '2019-01-09 00:00:00'),
("10", "u12345", "worksite_2", 'work_permit', '2019-01-09 00:00:00'),
("11", "u12345", "worksite_1", 'work_permit', '2019-01-09 00:00:00'),
("12", "u12345", "worksite_2", 'work_permit', '2019-01-09 00:00:00'),
("13", "u12345", "worksite_1", 'job', '2019-01-09 00:00:00'),
("14", "u12345", "worksite_2", 'work_permit', '2019-01-09 00:00:00'),
("15", "u12345", "worksite_1", 'work_permit', '2019-01-09 00:00:00')
;
查询＃1
SELECT
IFNULL(OnSite.worksite_id, Documents.worksite_id) as `Worksite`,
DATE(IFNULL(OnSite.timestamp, Documents.timestamp)) as `Date`,
COUNT(Documents.worksite_id) as `Users_on_Site`,
COUNT(DISTINCT OnSite.uid) as `Completed`
FROM OnSite
LEFT JOIN Documents ON OnSite.worksite_id = Documents.worksite_id AND DATE(OnSite.timestamp) = DATE(Documents.timestamp)
GROUP BY `Date`, `Worksite`;
| Worksite | Date | Users_on_Site | Completed |
| ---------- | ---------- | ------------- | --------- |
| worksite_1 | 2019-01-01 | 2 | 2 |
| worksite_1 | 2019-01-02 | 0 | 2 |
| worksite_1 | 2019-01-03 | 1 | 1 |
| worksite_1 | 2019-01-04 | 0 | 1 |
| worksite_1 | 2019-01-05 | 2 | 2 |
| worksite_1 | 2019-01-06 | 0 | 2 |
答案 0 :(得分：2)
以下是用于BigQuery标准SQL
StationIds如果要应用于问题的样本数据
#standardSQL
SELECT
IFNULL(OnSite.worksite_id, Documents.worksite_id) AS `Worksite`,
IFNULL(OnSite.timestamp, DATE(Documents.timestamp)) AS `DATE`,
COUNT(Documents.worksite_id) AS `Users_on_Site`,
COUNT(DISTINCT OnSite.uid) AS `Completed`
FROM `project.dataset.OnSite` OnSite
LEFT JOIN `project.dataset.Documents` Documents
ON OnSite.worksite_id = Documents.worksite_id
AND OnSite.timestamp = DATE(Documents.timestamp)
GROUP BY `DATE`, `Worksite`
结果将符合预期
WITH `project.dataset.OnSite` AS (
SELECT "u12345" uid, "worksite_1" worksite_id, DATE '2019-01-01' `TIMESTAMP` UNION ALL
SELECT "u12345", "worksite_1", '2019-01-02' UNION ALL
SELECT "u12345", "worksite_1", '2019-01-03' UNION ALL
SELECT "u12345", "worksite_1", '2019-01-04' UNION ALL
SELECT "u12345", "worksite_1", '2019-01-05' UNION ALL
SELECT "u12345", "worksite_1", '2019-01-06' UNION ALL
SELECT "u1", "worksite_1", '2019-01-01' UNION ALL
SELECT "u1", "worksite_1", '2019-01-02' UNION ALL
SELECT "u1", "worksite_1", '2019-01-05' UNION ALL
SELECT "u1", "worksite_1", '2019-01-06'
), `project.dataset.Documents` AS (
SELECT "1" document_id, "u12345" uid, "worksite_1" worksite_id, 'work_permit' type, TIMESTAMP '2019-01-01 00:00:00' `TIMESTAMP` UNION ALL
SELECT "2", "u12345", "worksite_2", 'job', '2019-01-02 00:00:00' UNION ALL
SELECT "3", "u12345", "worksite_1", 'work_permit', '2019-01-03 00:00:00' UNION ALL
SELECT "4", "u12345", "worksite_2", 'job', '2019-01-04 00:00:00' UNION ALL
SELECT "5", "u12345", "worksite_1", 'work_permit', '2019-01-05 00:00:00' UNION ALL
SELECT "6", "u12345", "worksite_2", 'job', '2019-01-06 00:00:00' UNION ALL
SELECT "7", "u12345", "worksite_1", 'work_permit', '2019-01-07 00:00:00' UNION ALL
SELECT "8", "u12345", "worksite_2", 'work_permit', '2019-01-09 00:00:00' UNION ALL
SELECT "9", "u12345", "worksite_1", 'job', '2019-01-09 00:00:00' UNION ALL
SELECT "10", "u12345", "worksite_2", 'work_permit', '2019-01-09 00:00:00' UNION ALL
SELECT "11", "u12345", "worksite_1", 'work_permit', '2019-01-09 00:00:00' UNION ALL
SELECT "12", "u12345", "worksite_2", 'work_permit', '2019-01-09 00:00:00' UNION ALL
SELECT "13", "u12345", "worksite_1", 'job', '2019-01-09 00:00:00' UNION ALL
SELECT "14", "u12345", "worksite_2", 'work_permit', '2019-01-09 00:00:00' UNION ALL
SELECT "15", "u12345", "worksite_1", 'work_permit', '2019-01-09 00:00:00'
)
答案 1 :(得分：0)
在BigQuery documentation中，解释了DATE(year, month, day)函数接受以下输入：
DATE(timestamp_expression[, timezone])：根据表示年，月和日的INT64值构造一个DATE。
DATE：将timestamp_expression转换为DATE数据类型。它支持一个可选参数来指定时区。如果未指定时区，则使用默认时区UTC。
在您的用例中，您传递给DATETIME_TRUNC的值似乎已经是一个日期时间。为此，您可以使用DATETIME_TRUNC(IFNULL(OnSite.timestamp, Documents.timestamp), DAY)
，例如：
Private Sub Form_Load()
Dim clmX As ColumnHeader
Dim itmX As ListItem
Dim i As Integer
For i = 1 To 3
Set clmX = ListView1.ColumnHeaders.Add()
clmX.Text = "Column " & i
Next i
' Inclui 10 items com o mesmo ícone
For i = 1 To 10
Set itmX = ListView1.ListItems.Add()
itmX.SmallIcon = 1
itmX.Text = "ListItem " & i
itmX.SubItems(1) = "Subitem 1"
itmX.SubItems(2) = "Subitem 2"
If i = 2 Then
'here
'itmX.removeCheckbox
End If
Next i
End Sub
答案 2 :(得分：0)
您为什么不强行铸造一切并使生活更轻松:-)？所有这些都应该起作用：
select
date(timestamp('2019-01-02')),
date(timestamp('2019-01-02 00:00:00')),
date(timestamp(null)))
因此，在您的if null语句中：
SELECT
IFNULL(OnSite.worksite_id, Documents.worksite_id) as `Worksite`,
IFNULL(date(datetime(OnSite.timestamp)),date(datetime(Documents.timestamp))) as `Date`,
COUNT(Documents.worksite_id) as `Users_on_Site`,
COUNT(DISTINCT OnSite.uid) as `Completed`
FROM OnSite
LEFT JOIN Documents ON OnSite.worksite_id = Documents.worksite_id AND DATE(datetime(OnSite.timestamp)) = DATE(datetime(Documents.timestamp))
GROUP BY `Date`, `Worksite`;