[[["容易理解","easyToUnderstand","thumb-up"],["確實解決了我的問題","solvedMyProblem","thumb-up"],["其他","otherUp","thumb-up"]],[["難以理解","hardToUnderstand","thumb-down"],["資訊或程式碼範例有誤","incorrectInformationOrSampleCode","thumb-down"],["缺少我需要的資訊/範例","missingTheInformationSamplesINeed","thumb-down"],["翻譯問題","translationIssue","thumb-down"],["其他","otherDown","thumb-down"]],["上次更新時間：2025-07-31 (世界標準時間)。"],[],[],null,["# Error: Redefinition of field\n\nWhen you are working on a LookML file, you might come across an error in the form `Redefinition of field 'view_name.field_name'` after you validate your code with the [Content Validator](/looker/docs/content-validation).\n\n\nThe error will appear under **LookML Errors** in the **Project Health Panel** [after the LookmL validator is run](/looker/docs/lookml-validation#running_validation).\n\n\nThis page will help you understand the error's meaning, common causes, and how to troubleshoot.\n\nCommon causes of Error: Redefinition of field\n---------------------------------------------\n\n\nThe error `Redefinition of field 'view_name.field_name'` means that Looker has identified two fields with exactly the same combination of view and field names.\n\n\nThere are several common causes of the error:\n\n- You have accidentally named two fields with the same name in the same view. This could be:\n - Two dimensions with the same name\n - Two measures with the same name\n - One dimension and one measure with the same name\n- You copied and pasted a field in a view and forgot to change the name.\n- You joined a view to your Explore a second time but forgot to give the join a different name.\n- You used the LookML generator to create your LookML project and created duplicate fields. \u003cbr /\u003e\n\n\n For example, you use the LookmL generator and your data table has a column named `count`. In this case, Looker will create a dimension named `count`, which references the column in your table. By default, Looker will also create a measure named `count` (which is the only default measure that Looker creates). Since the two fields are both named `count`, the error occurs.\n\n\nThe next section of this page will help you identify the view in your LookML project that is the source of the error.\n\nFinding the view mentioned in the error\n---------------------------------------\n\n\nKeep in mind that the view name that is mentioned in the error will be [the view name as it is defined in the `explore` parameter](/looker/docs/reference/param-explore-view-name) where the view is joined.\n\n\nFor the typical case, the view name is easy to understand. For example, you could have the following join: \n\n```\njoin: address\nforeign_key: order.billing_id\n```\n\n\nIn this example, the view name that is mentioned in the error is `address`, as specified in the `join` parameter.\n\n### Finding the source view when a view name is aliased in a join\n\n\nIf you are using an alias to change the way a view name is displayed in a join, the alias name will be mentioned in the error message. For example, suppose you have a join using the [`from` parameter](/looker/docs/reference/param-explore-join-from). The `from` parameter lets you give the join a different name than the underlying view, which is useful when you want to join the same view a second time. \n\n```\njoin: billing_address\nfrom: address\nforeign_key: order.billing_id\n```\n\n\nIn this example, the view name that is mentioned in the error from the LookML view file will be `billing_address` and not `address`."]]
