我没有“完整”版本的 MS SQL (SQL Express 2008)，所以我没有分析器工具。
我想查看我的实体框架代码生成的 SQL，但我找到的所有示例都使用了
var x = from u in table
select u;
语法类型；但我的大多数查询更像是..
var x = context.Users.Single(n => n.Name == "Steven");
语法类型。我可以做些什么来查看从这种编码方式生成的 SQL？有什么想法吗？
【问题讨论】：
看看这个link...它有一个 EF4 的跟踪提供程序。
我将尝试根据我在单元测试中的使用方式给出一个示例。
有几种方法可以配置提供程序。对于我的单元测试，我通过调用静态方法 RegisterProvider();
在代码中配置了提供程序[AssemblyInitialize()]
public static void AssemblyInit(TestContext context) {
EFTracingProviderConfiguration.RegisterProvider();
}
public partial class ExtendedNorthwindEntities : NorthwindEntities {
private TextWriter logOutput;
public ExtendedNorthwindEntities(string connectionString)
: base(EntityConnectionWrapperUtils.CreateEntityConnectionWithWrappers(
connectionString,
"EFTracingProvider")) {
}
#region Tracing Extensions
private EFTracingConnection TracingConnection {
get { return this.UnwrapConnection<EFTracingConnection>(); }
}
public event EventHandler<CommandExecutionEventArgs> CommandExecuting {
add { this.TracingConnection.CommandExecuting += value; }
remove { this.TracingConnection.CommandExecuting -= value; }
}
public event EventHandler<CommandExecutionEventArgs> CommandFinished {
add { this.TracingConnection.CommandFinished += value; }
remove { this.TracingConnection.CommandFinished -= value; }
}
public event EventHandler<CommandExecutionEventArgs> CommandFailed {
add { this.TracingConnection.CommandFailed += value; }
remove { this.TracingConnection.CommandFailed -= value; }
}
private void AppendToLog(object sender, CommandExecutionEventArgs e) {
if (this.logOutput != null) {
this.logOutput.WriteLine(e.ToTraceString().TrimEnd());
this.logOutput.WriteLine();
}
}
public TextWriter Log {
get { return this.logOutput; }
set {
if ((this.logOutput != null) != (value != null)) {
if (value == null) {
CommandExecuting -= AppendToLog;
}
else {
CommandExecuting += AppendToLog;
}
}
this.logOutput = value;
}
}
#endregion
}
第 3 步：附加到日志属性
var context = new ExtendedNorthwindEntities("name=\"NorthwindEntities\"");
context.Log = System.Console.Out;
【讨论】：
Express Edition 是否支持扩展事件？如果是这样，这将以与 Profiler 类似的方式捕获语句和 sp 完成的事件。
编辑：我已将其更改为使用内存目标而不是文件目标。理想情况下，取消注释 WHERE 部分并替换为适当的用户名以仅捕获感兴趣的事件，或者您可以使用 WHERE (([sqlserver].[session_id]=(56))) 按 spid 进行过滤。
IF EXISTS(SELECT * FROM sys.server_event_sessions WHERE name='test_trace')
DROP EVENT SESSION [test_trace] ON SERVER;
CREATE EVENT SESSION [test_trace]
ON SERVER
ADD EVENT sqlserver.sp_statement_completed(
ACTION (package0.callstack, sqlserver.session_id, sqlserver.sql_text)
-- WHERE (([sqlserver].[username]='Domain\Username'))
),
ADD EVENT sqlserver.sql_statement_completed(
ACTION (package0.callstack, sqlserver.session_id, sqlserver.sql_text)
--WHERE (([sqlserver].[username]='Domain\Username'))
)
ADD TARGET package0.ring_buffer
WITH (MAX_MEMORY = 4096KB, EVENT_RETENTION_MODE = ALLOW_SINGLE_EVENT_LOSS,
MAX_DISPATCH_LATENCY = 1 SECONDS, MAX_EVENT_SIZE = 0KB,
MEMORY_PARTITION_MODE = NONE, TRACK_CAUSALITY = OFF, STARTUP_STATE = OFF)
ALTER EVENT SESSION [test_trace] ON SERVER STATE = START
并查看结果（使用Adam Machanic's XE Code Generator 生成的查询）
DECLARE
@session_name VARCHAR(200) = 'test_trace'
SELECT
pivoted_data.*
FROM
(
SELECT MIN(event_name) AS event_name,
MIN(event_timestamp) AS event_timestamp,
unique_event_id,
CONVERT ( BIGINT, MIN (
CASE
WHEN d_name = 'cpu'
AND d_package IS NULL
THEN d_value
END ) ) AS [cpu],
CONVERT ( BIGINT, MIN (
CASE
WHEN d_name = 'duration'
AND d_package IS NULL
THEN d_value
END ) ) AS [duration],
CONVERT ( BIGINT, MIN (
CASE
WHEN d_name = 'object_id'
AND d_package IS NULL
THEN d_value
END ) ) AS [object_id],
CONVERT ( INT, MIN (
CASE
WHEN d_name = 'object_type'
AND d_package IS NULL
THEN d_value
END ) ) AS [object_type],
CONVERT ( DECIMAL(28,0), MIN (
CASE
WHEN d_name = 'reads'
AND d_package IS NULL
THEN d_value
END ) ) AS [reads],
CONVERT ( VARCHAR(MAX), MIN (
CASE
WHEN d_name = 'session_id'
AND d_package IS NOT NULL
THEN d_value
END ) ) AS [session_id],
CONVERT ( INT, MIN (
CASE
WHEN d_name = 'source_database_id'
AND d_package IS NULL
THEN d_value
END ) ) AS [source_database_id],
CAST((SELECT CONVERT ( VARCHAR(MAX), MIN (
CASE
WHEN d_name = 'sql_text'
AND d_package IS NOT NULL
THEN d_value
END ) ) AS [processing-instruction(x)] FOR XML PATH('') ) AS XML) AS [sql_text],
CONVERT ( DECIMAL(28,0), MIN (
CASE
WHEN d_name = 'writes'
AND d_package IS NULL
THEN d_value
END ) ) AS [writes]
FROM
(
SELECT
*,
CONVERT(VARCHAR(400), NULL) AS attach_activity_id
FROM
(
SELECT
event.value('(@name)[1]', 'VARCHAR(400)') as event_name,
event.value('(@timestamp)[1]', 'DATETIME') as event_timestamp,
DENSE_RANK() OVER (ORDER BY event) AS unique_event_id,
n.value('(@name)[1]', 'VARCHAR(400)') AS d_name,
n.value('(@package)[1]', 'VARCHAR(400)') AS d_package,
n.value('((value)[1]/text())[1]', 'VARCHAR(MAX)') AS d_value,
n.value('((text)[1]/text())[1]', 'VARCHAR(MAX)') AS d_text
FROM
(
SELECT
(
SELECT
CONVERT(xml, target_data)
FROM sys.dm_xe_session_targets st
JOIN sys.dm_xe_sessions s ON
s.address = st.event_session_address
WHERE
s.name = @session_name
AND st.target_name = 'ring_buffer'
) AS [x]
FOR XML PATH(''), TYPE
) AS the_xml(x)
CROSS APPLY x.nodes('//event') e (event)
CROSS APPLY event.nodes('*') AS q (n)
) AS data_data
) AS activity_data
GROUP BY
unique_event_id
) AS pivoted_data;
【讨论】：