Azure数据工厂数据复制源中的查找活动-语法错误

Question

通过https://docs.microsoft.com/zh-cn/azure/data-factory/tutorial-incremental-copy-portal进行工作

我使用sqlReaderQuery进行了一个名为GetCurrentWatermarkValue的查找活动：

Select WaterMarkValue as CurrentWatermarkValue\nfrom WatermarkTable

我使用sqlReaderQuery进行了另一个名为GetNewWatermarkValue的活动：

select max(createdon) as NewWatermarkValue from shipment

然后，我尝试使用以下两种方式在源代码中同时使用它们：

select *
from Shipment
where CreatedOn > '@{activity('GetCurrentWatermarkValue').output.firstRow.CurrentWatermarkValue}' 
and CreatedOn <= '@{activity('GetNewWatermarkValue').output.firstRow.NewWatermarkValue}'

预览数据按钮为灰色（但是当我删除where条件时启用），因此明显存在错误

设置接收器后，我尝试设置映射。 单击“映射”选项卡上的“导入模式”，将得到：

A database operation failed with the following error: 'Incorrect syntax near 'GetCurrentWatermarkValue'.'. Activity ID:98794aa9-c866-48d6-b9ff-9cb277bac6ed

我想也许我应该使用添加动态内容选项，但这只是给

Query is required

我在某处阅读了在Lookup活动上设置“仅第一行”时，firstRow之后的文本。 应该是[TableName]，但这似乎不正确。

抬头：

{
    "name": "GetCurrentWatermarkValue",
    "type": "Lookup",
    "policy": ...,
    "typeProperties": {
        "source": {
            "type": "AzureSqlSource",
            "sqlReaderQuery": "Select WaterMarkValue as CurrentWatermarkValue\nfrom WatermarkTable"
        },
        "dataset": {
            "referenceName": "WatermarkTable",
            "type": "DatasetReference"
        }
    }
}

抬头：

{
    "name": "GetNewWatermarkValue",
    "type": "Lookup",
    "policy": ...,
    "typeProperties": {
        "source": {
            "type": "AzureSqlSource",
            "sqlReaderQuery": "select max(createdon) as NewWatermarkValue from shipment"
        },
        "dataset": {
            "referenceName": "ShipmentsTable",
            "type": "DatasetReference"
        }
    }
}

资料复制：

{
    "name": "ArchiveShipments",
    "type": "Copy",
    "dependsOn": [
        {
            "activity": "GetCurrentWatermarkValue",
            "dependencyConditions": [
                "Succeeded"
            ]
        },
        {
            "activity": "GetNewWatermarkValue",
            "dependencyConditions": [
                "Succeeded"
            ]
        }
    ],
    "policy": ...,
    "typeProperties": {
        "source": {
            "type": "AzureSqlSource",
            "sqlReaderQuery": {
                "value": "select *\nfrom Shipment\nwhere CreatedOn > '@{activity('GetCurrentWatermarkValue').output.firstRow.CurrentWatermarkValue}' \nand CreatedOn <= '@{activity('GetNewWatermarkValue').output.firstRow.NewWatermarkValue}'",
                "type": "Expression"
            }
        },
        "sink": {
            "type": "AzureSqlSink"
        },
        "enableStaging": false
    },
    "inputs": [
        {
            "referenceName": "ShipmentsTable",
            "type": "DatasetReference"
        }
    ],
    "outputs": [
        {
            "referenceName": "ShipmentArchiveTable",
            "type": "DatasetReference"
        }
    ]
}

Answer 1

这看起来像是语法问题，请尝试以下为复制活动查询：

@{CONCAT('select * from Shipment where CreatedOn > ', activity('GetCurrentWatermarkValue').output.firstRow.CurrentWatermarkValue, ' and CreatedOn <= ', activity('GetNewWatermarkValue').output.firstRow.NewWatermarkValue}

除非要手动设置映射，否则不要使用映射，如果列名相同，则只需单击“清除”。

希望这对您有所帮助！