convert string to date format in azure data factory using set variable

Question

I have string date in set variable "20211222" and i want to convert it into date format like 2021-12-22. And i have use this function
@formatDateTime('20211222', 'yyyy-MM-dd')
But an error occur
In function 'formatDateTime', the value provided for date time string '20211222' was not valid. The datetime string must match ISO 8601 format
Is there any function to convert this string "20211222" into date?

Answer 1

Hey,
You can use the below logic :

@concat(substring(pipeline().parameters.Test,0,4 ),'-',substring(pipeline().parameters.Test,4,2),'-',substring(pipeline().parameters.Test,6,2))  

Using dataflows:

https://learn.microsoft.com/en-us/answers/questions/135485/azure-data-factory-date-conversion.html

{  
    "name": "pipeline1",  
    "properties": {  
        "activities": [  
            {  
                "name": "Set variable1",  
                "type": "SetVariable",  
                "dependsOn": [],  
                "userProperties": [],  
                "typeProperties": {  
                    "variableName": "Test",  
                    "value": {  
                        "value": "@concat(substring(pipeline().parameters.Test,0,4 ),'-',substring(pipeline().parameters.Test,4,2),'-',substring(pipeline().parameters.Test,6,2))",  
                        "type": "Expression"  
                    }  
                }  
            }  
        ],  
        "parameters": {  
            "Test": {  
                "type": "string",  
                "defaultValue": "20221223"  
            }  
        },  
        "variables": {  
            "Test": {  
                "type": "String"  
            }  
        },  
        "annotations": []  
    }  
}