本頁面中的部分或全部資訊可能不適用於 Trusted Cloud by S3NS。
分類總覽
機器學習的常見用途，就是使用以類似已標記資料訓練的模型，分類新資料。舉例來說，您可能想預測電子郵件是否為垃圾郵件，或是顧客的產品評論是正面、負面或中立。
您可以搭配下列任一模型使用 ML.PREDICT 函式來執行分類作業：
建議的知識
只要使用 CREATE MODEL 陳述式和 ML.PREDICT 函式中的預設設定，即使沒有太多機器學習知識，也能建立及使用分類模型。不過，瞭解機器學習開發的基本知識，有助您最佳化資料和模型，進而獲得更優異的結果。建議您參考下列資源，熟悉機器學習技術和程序：
除非另有註明，否則本頁面中的內容是採用創用 CC 姓名標示 4.0 授權，程式碼範例則為阿帕契 2.0 授權。詳情請參閱《Google Developers 網站政策》。Java 是 Oracle 和/或其關聯企業的註冊商標。
上次更新時間：2025-08-17 (世界標準時間)。
[[["容易理解","easyToUnderstand","thumb-up"],["確實解決了我的問題","solvedMyProblem","thumb-up"],["其他","otherUp","thumb-up"]],[["缺少我需要的資訊","missingTheInformationINeed","thumb-down"],["過於複雜/步驟過多","tooComplicatedTooManySteps","thumb-down"],["過時","outOfDate","thumb-down"],["翻譯問題","translationIssue","thumb-down"],["示例/程式碼問題","samplesCodeIssue","thumb-down"],["其他","otherDown","thumb-down"]],["上次更新時間：2025-08-17 (世界標準時間)。"],[[["\u003cp\u003eMachine learning classification involves using a model trained on labeled data to classify new data, such as identifying spam emails or categorizing customer reviews.\u003c/p\u003e\n"],["\u003cp\u003eThe \u003ccode\u003eML.PREDICT\u003c/code\u003e function can be used with various classification models, including logistic regression, boosted tree, random forest, deep neural network (DNN), wide & deep, and AutoML models.\u003c/p\u003e\n"],["\u003cp\u003eDifferent models can be specified using the \u003ccode\u003eMODEL_TYPE\u003c/code\u003e option, such as \u003ccode\u003eLOGISTIC_REG\u003c/code\u003e, \u003ccode\u003eBOOSTED_TREE_CLASSIFIER\u003c/code\u003e, \u003ccode\u003eRANDOM_FOREST_CLASSIFIER\u003c/code\u003e, \u003ccode\u003eDNN_CLASSIFIER\u003c/code\u003e, \u003ccode\u003eDNN_LINEAR_COMBINED_CLASSIFIER\u003c/code\u003e, and \u003ccode\u003eAUTOML_CLASSIFIER\u003c/code\u003e.\u003c/p\u003e\n"],["\u003cp\u003eWhile classification models can be created and used without extensive ML knowledge, understanding the basics can help optimize both data and the model for better results.\u003c/p\u003e\n"],["\u003cp\u003eResources like the Machine Learning Crash Course, Intro to Machine Learning, and Intermediate Machine Learning are recommended for gaining familiarity with machine learning techniques.\u003c/p\u003e\n"]]],[],null,["# Classification overview\n=======================\n\nA common use case for machine learning is classifying new data by using a model\ntrained on similar labeled data. For example, you might want to predict whether\nan email is spam, or whether a customer product review is positive, negative, or\nneutral.\n\nYou can use any of the following models in combination with the\n[`ML.PREDICT` function](/bigquery/docs/reference/standard-sql/bigqueryml-syntax-predict)\nto perform classification:\n\n- [Logistic regression models](/bigquery/docs/reference/standard-sql/bigqueryml-syntax-create-glm): use [logistic regression](https://developers.google.com/machine-learning/crash-course/logistic-regression) by setting the `MODEL_TYPE` option to `LOGISTIC_REG`.\n- [Boosted tree models](/bigquery/docs/reference/standard-sql/bigqueryml-syntax-create-boosted-tree): use a [gradient boosted decision tree](https://developers.google.com/machine-learning/decision-forests/intro-to-gbdt) by setting the `MODEL_TYPE` option to `BOOSTED_TREE_CLASSIFIER`.\n- [Random forest models](/bigquery/docs/reference/standard-sql/bigqueryml-syntax-create-random-forest): use a [random forest](https://developers.google.com/machine-learning/decision-forests/intro-to-decision-forests) by setting the `MODEL_TYPE` option to `RANDOM_FOREST_CLASSIFIER`.\n- [Deep neural network (DNN) models](/bigquery/docs/reference/standard-sql/bigqueryml-syntax-create-dnn-models): use a [neural network](https://developers.google.com/machine-learning/crash-course/neural-networks) by setting the `MODEL_TYPE` option to `DNN_CLASSIFIER`.\n- [Wide \\& Deep models](/bigquery/docs/reference/standard-sql/bigqueryml-syntax-create-wnd-models): use [wide \\& deep learning](https://dl.acm.org/doi/10.1145/2988450.2988454) by setting the `MODEL_TYPE` option to `DNN_LINEAR_COMBINED_CLASSIFIER`.\n- [AutoML models](/bigquery/docs/reference/standard-sql/bigqueryml-syntax-create-automl): use an [AutoML classification model](/vertex-ai/docs/tabular-data/classification-regression/overview) by setting the `MODEL_TYPE` option to `AUTOML_CLASSIFIER`.\n\nRecommended knowledge\n---------------------\n\nBy using the default settings in the `CREATE MODEL` statements and the\n`ML.PREDICT` function, you can create and use a classification model even\nwithout much ML knowledge. However, having basic knowledge about\nML development helps you optimize both your data and your model to\ndeliver better results. We recommend using the following resources to develop\nfamiliarity with ML techniques and processes:\n\n- [Machine Learning Crash Course](https://developers.google.com/machine-learning/crash-course)\n- [Intro to Machine Learning](https://www.kaggle.com/learn/intro-to-machine-learning)\n- [Intermediate Machine Learning](https://www.kaggle.com/learn/intermediate-machine-learning)"]]
