[[["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,["# COUNT\n\nThe `COUNT` function counts the number of items in a field.\n\nSyntax\n------\n\n`COUNT( `\u003cvar translate=\"no\"\u003eX\u003c/var\u003e` )`\n\n### Parameters\n\n- \u003cvar translate=\"no\"\u003eX\u003c/var\u003e - a field or expression that contains the items to be counted.\n\nHow the `COUNT` function works\n------------------------------\n\nThe `COUNT` function takes one parameter, which can be the name of a metric, dimension, or an expression of any type. `COUNT` returns the total number of items in that field or expression, including duplicates.\n\nTo count only unique items, use `COUNT_DISTINCT` or `APPROX_COUNT_DISTINCT`.\n\u003e There are 2 other ways to apply this function:\n\u003e\n\u003e - In a data source, change a field's **Aggregation** type to `Count`.\n\u003e - in a report, [edit the field's aggregation](/looker/docs/studio/edit-fields-in-your-reports) in a chart.\n\nExamples\n--------\n\n`COUNT(Page)` - counts the number of non-unique values in the **Page** dimension.\n\nLimits of `COUNT`\n-----------------\n\nYou can't apply this function to a pre-aggregated field ( **Aggregation** type of **Auto** ), or to an expression which is the result of another aggregation function. For example, a formula such as `COUNT(SUM(x))` will produce an error.\n\nRelated resources\n-----------------\n\n- [Calculated fields](/looker/docs/studio/about-calculated-fields)\n- [Looker Studio function list](/looker/docs/studio/function-list)"]]