Azure 数据工厂中的设置变量活动Set Variable Activity in Azure Data Factory

• 06/29/2020
• • 

适用于： Azure 数据工厂 Azure Synapse Analytics（预览版）APPLIES TO: Azure Data Factory Azure Synapse Analytics (Preview)

使用“设置变量”活动可设置数据工厂管道中定义的 String、Bool 或 Array 类型的现有变量的值。Use the Set Variable activity to set the value of an existing variable of type String, Bool, or Array defined in a Data Factory pipeline.

Type 属性Type properties

递增变量Incrementing a variable

涉及 Azure 数据工厂中的变量的常见情景是将变量用作 until 或 foreach 活动中的迭代器。A common scenario involving variables in Azure Data Factory is using a variable as an iterator within an until or foreach activity. 在设置变量活动中，无法引用在 value 字段中设置的变量。In a set variable activity you cannot reference the variable being set in the value field. 若要解决此限制，请设置一个临时变量，然后创建第二个设置变量活动。To workaround this limitation, set a temporary variable and then create a second set variable activity. 第二个设置变量活动会将迭代器的值设置为临时变量。The second set variable activity sets the value of the iterator to the temporary variable.

下面是此模式的示例：Below is an example of this pattern:

{
    "name": "pipeline3",
    "properties": {
        "activities": [
            {
                "name": "Set I",
                "type": "SetVariable",
                "dependsOn": [
                    {
                        "activity": "Increment J",
                        "dependencyConditions": [
                            "Succeeded"
                        ]
                    }
                ],
                "userProperties": [],
                "typeProperties": {
                    "variableName": "i",
                    "value": {
                        "value": "@variables('j')",
                        "type": "Expression"
                    }
                }
            },
            {
                "name": "Increment J",
                "type": "SetVariable",
                "dependsOn": [],
                "userProperties": [],
                "typeProperties": {
                    "variableName": "j",
                    "value": {
                        "value": "@string(add(int(variables('i')), 1))",
                        "type": "Expression"
                    }
                }
            }
        ],
        "variables": {
            "i": {
                "type": "String",
                "defaultValue": "0"
            },
            "j": {
                "type": "String",
                "defaultValue": "0"
            }
        },
        "annotations": []
    }
}

后续步骤Next steps

了解数据工厂支持的相关控制流活动：Learn about a related control flow activity supported by Data Factory:

• 追加变量活动Append Variable Activity