Question

我目前在查询中遇到问题。我不知道为什么它不起作用。这是我的问题：

INSERT INTO tbl_leave_count (leave_count,leave_user_id,leave_id)
SELECT COUNT(*) as leaveCount, leave_user_id,leave_id
FROM tbl_leaverequest
WHERE leave_user_id=2 AND leave_id = 1
ON DUPLICATE KEY UPDATE leave_count = leaveCount;

但是当我将更新离开计数的值替换为数字时，它可以工作：

INSERT INTO tbl_leave_count (leave_count,leave_user_id,leave_id)
SELECT COUNT(*) as leaveCount, leave_user_id,leave_id
FROM tbl_leaverequest
WHERE leave_user_id=2 AND leave_id =1
ON DUPLICATE KEY UPDATE leave_count=5;

我想从查询中的select语句中获取值[COUNT（*）as leaveCount]。我该怎么办？

Answer 1

列名应该相同

INSERT INTO tbl_leave_count (leave_count,leave_user_id,leave_id) 
(SELECT COUNT(*) as leave_count, leave_user_id,leave_id FROM tbl_leaverequest  WHERE leave_user_id=2 AND leave_id =1)
ON DUPLICATE KEY UPDATE leave_count=5;

Answer 2

您可以尝试使用子查询：

$XmlFile = Get-Item($xmlFileName)
    # Perform the XSD Validation
    $readerSettings = New-Object -TypeName System.Xml.XmlReaderSettings
    $readerSettings.Schemas.Add($compiledSchema)
    $readerSettings.ValidationType = [System.Xml.ValidationType]::Schema
    $readerSettings.ValidationFlags = [System.Xml.Schema.XmlSchemaValidationFlags]::ProcessInlineSchema -bor [System.Xml.Schema.XmlSchemaValidationFlags]::ProcessSchemaLocation
    $readerSettings.add_ValidationEventHandler(
    {
        # Triggered each time an error is found in the XML file
        Write-Host $("ERROR line $($_.exception.LineNumber) position $($_.exception.LinePosition) in '$xmlFileName': " + $_.Message) -ForegroundColor Red
        $script:errorCount++
    });
    $reader = [System.Xml.XmlReader]::Create($XmlFile.FullName, $readerSettings)
    while ($reader.Read()) { }
    $reader.Close()

我认为您的原始INSERT INTO tbl_leave_count (leave_count, leave_user_id, leave_id) SELECT leaveCount, leave_user_id, leave_id FROM ( SELECT (SELECT COUNT(*) FROM tbl_leaverequest WHERE leave_user_id = 2 AND leave_id = 1) AS leaveCount, leave_user_id, leave_id FROM tbl_leaverequest WHERE leave_user_id = 2 AND leave_id = 1 ) t ON DUPLICATE KEY UPDATE leave_count = t.leaveCount;存在问题，因为SELECT出现非聚合列。考虑到COUNT(*)子句中的条件，我使用子查询来查找tbl_leaverequest的计数。

在INSERT SELECT ON DUPLICATE KEY UPDATE

2 个答案: