次のコード例は、以下を実行する方法を示しています。
SELECT ステートメントを実行して項目を取得する。
INSERT 文を実行して項目を追加する。
UPDATE ステートメントを使用して項目を更新する。
DELETE ステートメントを実行して項目を削除する。
- AWS SDK for .NET
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注記
GitHub には、その他のリソースもあります。AWS コード例リポジトリ
で全く同じ例を見つけて、設定と実行の方法を確認してください。 namespace PartiQL_Basics_Scenario { public class PartiQLMethods { private static readonly AmazonDynamoDBClient Client = new AmazonDynamoDBClient(); /// <summary> /// Inserts movies imported from a JSON file into the movie table by /// using an Amazon DynamoDB PartiQL INSERT statement. /// </summary> /// <param name="tableName">The name of the table where the movie /// information will be inserted.</param> /// <param name="movieFileName">The name of the JSON file that contains /// movie information.</param> /// <returns>A Boolean value that indicates the success or failure of /// the insert operation.</returns> public static async Task<bool> InsertMovies(string tableName, string movieFileName) { // Get the list of movies from the JSON file. var movies = ImportMovies(movieFileName); var success = false; if (movies is not null) { // Insert the movies in a batch using PartiQL. Because the // batch can contain a maximum of 25 items, insert 25 movies // at a time. string insertBatch = $"INSERT INTO {tableName} VALUE {{'title': ?, 'year': ?}}"; var statements = new List<BatchStatementRequest>(); try { for (var indexOffset = 0; indexOffset < 250; indexOffset += 25) { for (var i = indexOffset; i < indexOffset + 25; i++) { statements.Add(new BatchStatementRequest { Statement = insertBatch, Parameters = new List<AttributeValue> { new AttributeValue { S = movies[i].Title }, new AttributeValue { N = movies[i].Year.ToString() }, }, }); } var response = await Client.BatchExecuteStatementAsync(new BatchExecuteStatementRequest { Statements = statements, }); // Wait between batches for movies to be successfully added. System.Threading.Thread.Sleep(3000); success = response.HttpStatusCode == System.Net.HttpStatusCode.OK; // Clear the list of statements for the next batch. statements.Clear(); } } catch (AmazonDynamoDBException ex) { Console.WriteLine(ex.Message); } } return success; } /// <summary> /// Loads the contents of a JSON file into a list of movies to be /// added to the DynamoDB table. /// </summary> /// <param name="movieFileName">The full path to the JSON file.</param> /// <returns>A generic list of movie objects.</returns> public static List<Movie> ImportMovies(string movieFileName) { if (!File.Exists(movieFileName)) { return null!; } using var sr = new StreamReader(movieFileName); string json = sr.ReadToEnd(); var allMovies = JsonConvert.DeserializeObject<List<Movie>>(json); if (allMovies is not null) { // Return the first 250 entries. return allMovies.GetRange(0, 250); } else { return null!; } } /// <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; } /// <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; } /// <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; } /// <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; } /// <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 = $"DELETE FROM {tableName} WHERE title = ? AND year = ?"; var response = await Client.ExecuteStatementAsync(new ExecuteStatementRequest { Statement = deleteSingle, Parameters = new List<AttributeValue> { new AttributeValue { S = movieTitle }, new AttributeValue { N = year.ToString() }, }, }); return response.HttpStatusCode == System.Net.HttpStatusCode.OK; } /// <summary> /// Displays the list of movies returned from a database query. /// </summary> /// <param name="items">The list of movie information to display.</param> private static void DisplayMovies(List<Dictionary<string, AttributeValue>> items) { if (items.Count > 0) { Console.WriteLine($"Found {items.Count} movies."); items.ForEach(item => Console.WriteLine($"{item["year"].N}\t{item["title"].S}")); } else { Console.WriteLine($"Didn't find a movie that matched the supplied criteria."); } } } } /// <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; } /// <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; } /// <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; } /// <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; }-
API の詳細については、「AWS SDK for .NET API リファレンス」の「ExecuteStatement」を参照してください。
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AWS SDK デベロッパーガイドとコード例の詳細なリストについては、「AWS SDK で DynamoDB を使用する」を参照してください。このトピックには、使用開始方法に関する情報と、以前の SDK バージョンの詳細も含まれています。
