Azure Cosmos DB 中 Document API 存儲過程、觸發器、自定義函數的實現

時間 2019-12-10

標籤 azure cosmos document api 存儲過程觸發器自定義函數實現简体版

原文原文鏈接

閱讀大約須要 4 分鐘javascript

　　在上一篇隨筆中記錄的是關於Azure Cosmos DB 中SQL API (DocumentDB) 的簡介和Repository 的實現。本隨筆是Document DB 中存儲過程(Stored Procedure)、觸發器(Triggers)、用戶自定義函數(User Defined Functions)的實現方式。html

存儲過程(Stored Procedure)java

1. 建立存儲過程，須要四個參數，以此分別爲數據庫名，collection名，須要建立的存儲過程名，存儲過程的內容（內容使用的語言請參照官網：https://docs.microsoft.com/zh-cn/azure/cosmos-db/how-to-write-stored-procedures-triggers-udfs）sql

注：catch execption只是簡寫，拋出異常。數據庫

public async Task<bool> CreateStoredProcedureAsync(string databaseName, string collectionName, string storedProId, string body)
        {
            try
            {
                var sproc = new StoredProcedure()
                {
                    Id = storedProId,
                    Body = body
                };
                var uri = UriFactory.CreateDocumentCollectionUri(databaseName, collectionName);
                await TryDeleteStoredProcedure(uri, storedProId);
                var result = await _client.Value.CreateStoredProcedureAsync(uri, sproc);

                return result.StatusCode == HttpStatusCode.OK || result.StatusCode == HttpStatusCode.Created;
            }
            catch (Exception ex)
            {
                throw new Exception(ex.Message);
            }
        }

// 爲避免重複的存儲過程名 而引起的的異常（如下觸發器，自定義函數類同）。
private async Task TryDeleteStoredProcedure(Uri uri, string storedProId)
        {
            var sproc = _client.Value.CreateStoredProcedureQuery(uri).Where(x => x.Id == storedProId).AsEnumerable().FirstOrDefault();

            if (sproc != null)
            {
                await _client.Value.DeleteStoredProcedureAsync(sproc.SelfLink);
            }
        }

2. 讀取存儲過程，第四個參數(procedureParams)爲存儲過程可能須要的參數.async

public async Task<T> ExecuteStoredProcedureAsync<T>(string databaseName, string collectionName, string storedProId, params object[] procedureParams) where T : new()
        {
            StoredProcedureResponse<dynamic> result = await _client.Value.ExecuteStoredProcedureAsync<dynamic>(UriFactory.CreateStoredProcedureUri(databaseName, collectionName, storedProId), procedureParams);

            if (result.StatusCode == HttpStatusCode.OK)
            {
                return JsonConvert.DeserializeObject<T>(result.Response?.ToString());
            }

            throw new ArgumentException("Execute stored ptocedure failed");
        }

觸發器(Triggers)函數

1. 建立觸發器學習

public async Task<bool> CreateTriggerAsync(string databaseName, string collectionName, string triggerId, string triggerBody, TriggerOperation triggerOperation, TriggerType triggerType)
        {
            try
            {
                var trigger = new Trigger()
                {
                    Id = triggerId,
                    Body = triggerBody,
                    TriggerOperation = triggerOperation,
                    TriggerType = triggerType
                };
                var uri = UriFactory.CreateDocumentCollectionUri(databaseName, collectionName);
                await TryDeleteTrigger(uri, triggerId);
                var result = await _client.Value.CreateTriggerAsync(uri, trigger);

                return result.StatusCode == HttpStatusCode.OK || result.StatusCode == HttpStatusCode.Created;
            }
            catch (Exception ex)
            {
                throw new Exception(ex.Message);
            }
        }

private async Task TryDeleteTrigger(Uri uri, string triggerId)
        {
            var trigger = _client.Value.CreateTriggerQuery(uri).Where(x => x.Id == triggerId).AsEnumerable().FirstOrDefault();

            if (trigger != null)
            {
                await _client.Value.DeleteTriggerAsync(trigger.SelfLink);
            }
        }

以上代碼中有兩個傳入參數TriggerOperation 和 TriggerType。spa

　　TriggerOperation 參數有五種類型，分別爲：3d

　　　　All = 0,
　　　　Create = 1,
　　　　Update = 2,
　　　　Delete = 3,
　　　　Replace = 4

　　TriggerType 參數有兩種類型，分別爲前觸發器 TriggerType(Pre = 0)和後觸發器(Post = 1)。

2. 使用觸發器

public async Task<bool> CreateDocumentAsync<T>(string databaseName, string collectionName, T document, RequestOptions requestOptions) where T : class
        {
            try
            {
                await CreateDocumentCollectionAsync(collectionName, databaseName);
                var uri = UriFactory.CreateDocumentCollectionUri(databaseName, collectionName);

                var response = await _client.Value.CreateDocumentAsync(uri, document, requestOptions);

                bool result = (response != null && (response.StatusCode == HttpStatusCode.Created || response.StatusCode == HttpStatusCode.OK));

                return result;
            }
            catch (Exception ex)
            {
                throw new Exception(ex.Message);
            }
        }

其中RequestOptions 參數能夠做爲觸發器Id/name傳入，其中傳入的方式須要注意下，傳入的類型按照前觸發器和後觸發器兩種參入，如圖：

怎麼傳，舉個例子：var option = new RequestOptions() { PreTriggerInclude = new List<string>() { "GetBrithDate" } };

用戶自定義函數(User Defined Functions)

1. 建立用戶自定義函數

public async Task<bool> CreateUserDefinedFunctionAsync(string databaseName, string collectionName, string udfId, string body)
        {
            try
            {
                var udf = new UserDefinedFunction()
                {
                    Id = udfId,
                    Body = body
                };
                var uri = UriFactory.CreateDocumentCollectionUri(databaseName, collectionName);
                await TryDeleteUserDefinedFunction(uri, udfId);
                var result = await _client.Value.CreateUserDefinedFunctionAsync(uri, udf);

                return result.StatusCode == HttpStatusCode.OK || result.StatusCode == HttpStatusCode.Created;
            }
            catch (Exception ex)
            {
                throw new Exception(ex.Message);
            }
        }

private async Task TryDeleteUserDefinedFunction(Uri uri, string udfId)
        {
            var udf = _client.Value.CreateUserDefinedFunctionQuery(uri).Where(x => x.Id == udfId).AsEnumerable().FirstOrDefault();

            if (udf != null)
            {
                await _client.Value.DeleteUserDefinedFunctionAsync(udf.SelfLink);
            }
        }

2. 運用自定義函數

public async Task<IEnumerable<T>> GetDocumentByUDF<T>(string databaseName, string collectionName, string sqlExpression, FeedOptions feedOptions = null) where T : new()
        {
            try
            {
                var uri = UriFactory.CreateDocumentCollectionUri(databaseName, collectionName);
                var query = _client.Value.CreateDocumentQuery<T>(uri, sqlExpression, feedOptions).AsDocumentQuery();

                var results = new List<T>();
                while (query.HasMoreResults)
                {
                    results.AddRange(await query.ExecuteNextAsync<T>());
                }

                return results;
            }
            catch (Exception ex)
            {
                throw new Exception(ex.Message);
            }

        }

sqlExpression 爲傳入的sql 語句，具體這個sql 語句怎麼寫，例如：

其中數據庫中用戶自定義函數是這樣定義的：

function getTitle(profession) {

    if (profession === undefined)
        throw 'no input';

    if (profession === "Angular" || profession === "Vue" || profession  === "React")
        return "FrontEnd";
    else if (profession === "Net" || profession === "Java")
        return "BackEnd";
    else
        return "FullStack";
}

那麼 sqlExpression = $"SELECT * FROM c where udf.getTitle(c.Profession) = '{換成插入值}'";

簡單筆記，還有待繼續挖掘，正在繼續努力，想要了解和學習的還請切到Cosmos DB官網：https://docs.microsoft.com/zh-cn/azure/cosmos-db/how-to-write-stored-procedures-triggers-udfs

本隨筆連接：https://www.cnblogs.com/OneManStep/p/10266217.html