使用合并语句获取插入和更新的单独计数 - C# 和 SQL 服务器
Getting individual count of insert and update using merge statement - C# and SQL Server
我正在使用 MERGE
命令来插入行(使用 dapper ORM),我想分别获取单个插入和更新的计数。我已将合并操作转储到临时 table 以便稍后查询。当我检查数据库时,行被正确更新,但是我无法获得每个操作的计数
这里我通过 C# 添加了一个包含 3 个项目的列表,合并语句正确地添加了它们。
在检查存储操作(插入或更新)的结果时,我看到计数为 1 而不是 3
在 SSMS 中使用类似的源和目标执行时合并语句中使用的临时 table table returns table 具有正确的计数:
如果我做错了什么,请告诉我。谢谢。
我将粘贴 C# 代码以供参考:
public class Product
{
public int ProductID { get; set; }
public string ProductName { get; set; }
public int Rate { get; set; }
}
public async Task<IEnumerable<Tuple<string, int>>> UpsertProductCostAsync()
{
var products = new List<Product>
{
new Product {ProductID = 1, ProductName = "Tea", Rate = 10},
new Product {ProductID = 2, ProductName = "Coffee", Rate = 20},
new Product {ProductID = 3, ProductName = "Muffin", Rate = 30}
};
var mergeStatement = @"DROP TABLE IF EXISTS ##MergeActions
CREATE TABLE ##MergeActions ([MergeAction] VARCHAR(10))
INSERT INTO ##MergeActions ([MergeAction])
SELECT [MergeAction]
FROM
(MERGE [dbo].[Products] AS target
USING (VALUES (@ProductID, @ProductName, @Rate)) AS source (ProductID, ProductName, Rate)
ON (target.ProductID = source.ProductID)
WHEN MATCHED THEN
UPDATE
SET target.ProductName = source.ProductName,
target.Rate = source.Rate
WHEN NOT MATCHED THEN
INSERT ([ProductID],[ProductName], [Rate])
VALUES (source.ProductID, source.ProductName, source.Rate)
OUTPUT $action AS MergeAction) MergeOutput;
";
_con.Open();
var rowsAffected = await _con.ExecuteAsync(mergeStatement, products);
var operationsWithCount = await _con.QueryAsync(@"SELECT [MergeAction], COUNT(*) as [Count]
FROM ##MergeActions
GROUP BY MergeAction;");
var result = new List<Tuple<string, int>>();
foreach (var o in operationsWithCount)
{
result.Add(new Tuple<string, int>(o.MergeAction, o.Count));
}
return result;
}
SQL 服务器 table 定义:
CREATE TABLE Products
(
ProductID INT PRIMARY KEY,
ProductName VARCHAR(100),
Rate int
)
我建议从 SQL 服务器中的 table 值参数开始。这将让您传递产品列表并在相同的 SQL 命令中获得结果。
CREATE TYPE TVP_Product AS TABLE
(
ProductID integer not null,
ProductName varchar(100) not null,
Rate int not null
);
你的 C# 可能是:
public async Task<IEnumerable<Tuple<string, int>>> UpsertProductCostAsync()
{
var products = new List<Product>
{
new Product {ProductID = 1, ProductName = "Tea", Rate = 10},
new Product {ProductID = 2, ProductName = "Coffee", Rate = 20},
new Product {ProductID = 3, ProductName = "Muffin", Rate = 30}
};
// one approach to transforming a collection to a datatable.
// you could find / create an extension method to do this more succintly
var productsDt = new DataTable();
productsDt.Columns.Add("ProductID", typeof(int));
productsDt.Columns.Add("ProductName", typeof(string));
productsDt.Columns.Add("Rate", typeof(int));
foreach (var product in products)
productsDt.Rows.Add(product.ProductID, product.ProductName, product.Rate);
var mergeStatement = @"
MERGE INTO [dbo].[Products] AS target
USING (select ProductId, ProductName, Rate from @products) as source
ON (target.ProductID = source.ProductID)
WHEN MATCHED THEN
UPDATE
SET target.ProductName = source.ProductName,
target.Rate = source.Rate
WHEN NOT MATCHED THEN
INSERT ([ProductID],[ProductName], [Rate])
VALUES (source.ProductID, source.ProductName, source.Rate)
OUTPUT $action AS MergeAction;
";
_con.Open();
var actions = await _con.QueryAsync<string>(mergeStatement,
new {
products = productsDt.AsTableValuedParameter("TVP_Product")
}
);
var results = actions
.GroupBy(x => x, (y, z) =>
new Tuple<string, int>(y, z.Count()))
.ToList();
return results;
}
我正在使用 MERGE
命令来插入行(使用 dapper ORM),我想分别获取单个插入和更新的计数。我已将合并操作转储到临时 table 以便稍后查询。当我检查数据库时,行被正确更新,但是我无法获得每个操作的计数
这里我通过 C# 添加了一个包含 3 个项目的列表,合并语句正确地添加了它们。
在检查存储操作(插入或更新)的结果时,我看到计数为 1 而不是 3
在 SSMS 中使用类似的源和目标执行时合并语句中使用的临时 table table returns table 具有正确的计数:
如果我做错了什么,请告诉我。谢谢。
我将粘贴 C# 代码以供参考:
public class Product
{
public int ProductID { get; set; }
public string ProductName { get; set; }
public int Rate { get; set; }
}
public async Task<IEnumerable<Tuple<string, int>>> UpsertProductCostAsync()
{
var products = new List<Product>
{
new Product {ProductID = 1, ProductName = "Tea", Rate = 10},
new Product {ProductID = 2, ProductName = "Coffee", Rate = 20},
new Product {ProductID = 3, ProductName = "Muffin", Rate = 30}
};
var mergeStatement = @"DROP TABLE IF EXISTS ##MergeActions
CREATE TABLE ##MergeActions ([MergeAction] VARCHAR(10))
INSERT INTO ##MergeActions ([MergeAction])
SELECT [MergeAction]
FROM
(MERGE [dbo].[Products] AS target
USING (VALUES (@ProductID, @ProductName, @Rate)) AS source (ProductID, ProductName, Rate)
ON (target.ProductID = source.ProductID)
WHEN MATCHED THEN
UPDATE
SET target.ProductName = source.ProductName,
target.Rate = source.Rate
WHEN NOT MATCHED THEN
INSERT ([ProductID],[ProductName], [Rate])
VALUES (source.ProductID, source.ProductName, source.Rate)
OUTPUT $action AS MergeAction) MergeOutput;
";
_con.Open();
var rowsAffected = await _con.ExecuteAsync(mergeStatement, products);
var operationsWithCount = await _con.QueryAsync(@"SELECT [MergeAction], COUNT(*) as [Count]
FROM ##MergeActions
GROUP BY MergeAction;");
var result = new List<Tuple<string, int>>();
foreach (var o in operationsWithCount)
{
result.Add(new Tuple<string, int>(o.MergeAction, o.Count));
}
return result;
}
SQL 服务器 table 定义:
CREATE TABLE Products
(
ProductID INT PRIMARY KEY,
ProductName VARCHAR(100),
Rate int
)
我建议从 SQL 服务器中的 table 值参数开始。这将让您传递产品列表并在相同的 SQL 命令中获得结果。
CREATE TYPE TVP_Product AS TABLE
(
ProductID integer not null,
ProductName varchar(100) not null,
Rate int not null
);
你的 C# 可能是:
public async Task<IEnumerable<Tuple<string, int>>> UpsertProductCostAsync()
{
var products = new List<Product>
{
new Product {ProductID = 1, ProductName = "Tea", Rate = 10},
new Product {ProductID = 2, ProductName = "Coffee", Rate = 20},
new Product {ProductID = 3, ProductName = "Muffin", Rate = 30}
};
// one approach to transforming a collection to a datatable.
// you could find / create an extension method to do this more succintly
var productsDt = new DataTable();
productsDt.Columns.Add("ProductID", typeof(int));
productsDt.Columns.Add("ProductName", typeof(string));
productsDt.Columns.Add("Rate", typeof(int));
foreach (var product in products)
productsDt.Rows.Add(product.ProductID, product.ProductName, product.Rate);
var mergeStatement = @"
MERGE INTO [dbo].[Products] AS target
USING (select ProductId, ProductName, Rate from @products) as source
ON (target.ProductID = source.ProductID)
WHEN MATCHED THEN
UPDATE
SET target.ProductName = source.ProductName,
target.Rate = source.Rate
WHEN NOT MATCHED THEN
INSERT ([ProductID],[ProductName], [Rate])
VALUES (source.ProductID, source.ProductName, source.Rate)
OUTPUT $action AS MergeAction;
";
_con.Open();
var actions = await _con.QueryAsync<string>(mergeStatement,
new {
products = productsDt.AsTableValuedParameter("TVP_Product")
}
);
var results = actions
.GroupBy(x => x, (y, z) =>
new Tuple<string, int>(y, z.Count()))
.ToList();
return results;
}