以下代码示例演示如何使用 ExecuteStatement
。
操作示例是大型程序的代码摘录,必须在上下文中运行。在以下代码示例中,您可以查看此操作的上下文:
- AWS SDK for .NET
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注意
查看 GitHub,了解更多信息。查找完整示例,学习如何在 AWS 代码示例存储库
中进行设置和运行。 使用 INSERT 语句添加项目。
/// <summary> /// Inserts a single movie into the movies table. /// </summary> /// <param name="tableName">The name of the table.</param> /// <param name="movieTitle">The title of the movie to insert.</param> /// <param name="year">The year that the movie was released.</param> /// <returns>A Boolean value that indicates the success or failure of /// the INSERT operation.</returns> public static async Task<bool> InsertSingleMovie(string tableName, string movieTitle, int year) { string insertBatch = $"INSERT INTO {tableName} VALUE {{'title': ?, 'year': ?}}"; var response = await Client.ExecuteStatementAsync(new ExecuteStatementRequest { Statement = insertBatch, Parameters = new List<AttributeValue> { new AttributeValue { S = movieTitle }, new AttributeValue { N = year.ToString() }, }, }); return response.HttpStatusCode == System.Net.HttpStatusCode.OK; }
使用 SELECT 语句获取项目。
/// <summary> /// Uses a PartiQL SELECT statement to retrieve a single movie from the /// movie database. /// </summary> /// <param name="tableName">The name of the movie table.</param> /// <param name="movieTitle">The title of the movie to retrieve.</param> /// <returns>A list of movie data. If no movie matches the supplied /// title, the list is empty.</returns> public static async Task<List<Dictionary<string, AttributeValue>>> GetSingleMovie(string tableName, string movieTitle) { string selectSingle = $"SELECT * FROM {tableName} WHERE title = ?"; var parameters = new List<AttributeValue> { new AttributeValue { S = movieTitle }, }; var response = await Client.ExecuteStatementAsync(new ExecuteStatementRequest { Statement = selectSingle, Parameters = parameters, }); return response.Items; }
使用 SELECT 语句获取项目列表。
/// <summary> /// Retrieve multiple movies by year using a SELECT statement. /// </summary> /// <param name="tableName">The name of the movie table.</param> /// <param name="year">The year the movies were released.</param> /// <returns></returns> public static async Task<List<Dictionary<string, AttributeValue>>> GetMovies(string tableName, int year) { string selectSingle = $"SELECT * FROM {tableName} WHERE year = ?"; var parameters = new List<AttributeValue> { new AttributeValue { N = year.ToString() }, }; var response = await Client.ExecuteStatementAsync(new ExecuteStatementRequest { Statement = selectSingle, Parameters = parameters, }); return response.Items; }
使用 UPDATE 语句更新项目。
/// <summary> /// Updates a single movie in the table, adding information for the /// producer. /// </summary> /// <param name="tableName">the name of the table.</param> /// <param name="producer">The name of the producer.</param> /// <param name="movieTitle">The movie title.</param> /// <param name="year">The year the movie was released.</param> /// <returns>A Boolean value that indicates the success of the /// UPDATE operation.</returns> public static async Task<bool> UpdateSingleMovie(string tableName, string producer, string movieTitle, int year) { string insertSingle = $"UPDATE {tableName} SET Producer=? WHERE title = ? AND year = ?"; var response = await Client.ExecuteStatementAsync(new ExecuteStatementRequest { Statement = insertSingle, Parameters = new List<AttributeValue> { new AttributeValue { S = producer }, new AttributeValue { S = movieTitle }, new AttributeValue { N = year.ToString() }, }, }); return response.HttpStatusCode == System.Net.HttpStatusCode.OK; }
使用 DELETE 语句删除单个电影。
/// <summary> /// Deletes a single movie from the table. /// </summary> /// <param name="tableName">The name of the table.</param> /// <param name="movieTitle">The title of the movie to delete.</param> /// <param name="year">The year that the movie was released.</param> /// <returns>A Boolean value that indicates the success of the /// DELETE operation.</returns> public static async Task<bool> DeleteSingleMovie(string tableName, string movieTitle, int year) { var deleteSingle = $"DELETE FROM {tableName} WHERE title = ? AND year = ?"; var response = await Client.ExecuteStatementAsync(new ExecuteStatementRequest { Statement = deleteSingle, Parameters = new List<AttributeValue> { new AttributeValue { S = movieTitle }, new AttributeValue { N = year.ToString() }, }, }); return response.HttpStatusCode == System.Net.HttpStatusCode.OK; }
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有关 API 详细信息,请参阅《AWS SDK for .NET API 参考》中的 ExecuteStatement。
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有关 AWS SDK 开发人员指南和代码示例的完整列表,请参阅 结合使用 DynamoDB 与 AWS SDK。本主题还包括有关入门的信息以及有关先前的 SDK 版本的详细信息。