Dapper
本文内容摘自dapper官网
动态类型
public static IEnumerable<dynamic> Query (this IDbConnection cnn, string sql, object param = null, SqlTransaction transaction = null, bool buffered = true)
This method will execute SQL and return a dynamic list.
Example usage:
var rows = connection.Query("select 1 A, 2 B union all select 3, 4");
((int)rows[0].A)
.IsEqualTo(1);
((int)rows[0].B)
.IsEqualTo(2);
((int)rows[1].A)
.IsEqualTo(3);
((int)rows[1].B)
.IsEqualTo(4);
多次执行语句
Execute a Command multiple times
The same signature also allows you to conveniently and efficiently execute a command multiple times (for example to bulk-load data)
Example usage:
connection.Execute(@"insert MyTable(colA, colB) values (@a, @b)",
new[] { new { a=1, b=1 }, new { a=2, b=2 }, new { a=3, b=3 } }
).IsEqualTo(3); // 3 rows inserted: "1,1", "2,2" and "3,3"
This works for any parameter that implements IEnumerable for some T.
集合 支持
List Support
Dapper allow you to pass in IEnumerable and will automatically parameterize your query.
For example:
connection.Query<int>("select * from (select 1 as Id union all select 2 union all select 3) as X where Id in @Ids", new { Ids = new int[] { 1, 2, 3 });
Will be translated to:
select * from (select 1 as Id union all select 2 union all select 3) as X where Id in (@Ids1, @Ids2, @Ids3)" // @Ids1 = 1 , @Ids2 = 2 , @Ids2 = 3
一次执行多条语句
Multiple Results
Dapper allows you to process multiple result grids in a single query.
Example:
var sql =
@"
select * from Customers where CustomerId = @id
select * from Orders where CustomerId = @id
select * from Returns where CustomerId = @id";
using (var multi = connection.QueryMultiple(sql, new {id=selectedId}))
{
var customer = multi.Read<Customer>().Single();
var orders = multi.Read<Order>().ToList();
var returns = multi.Read<Return>().ToList();
...
}
