Database component Hxj.data (10) (SQL for Output component execution)

TX message asked the front of the SQL is how the page, read this article you will know.

Component can output executed SQL to facilitate viewing SQL generated statements for problems.

To output SQL by registering events

DbSession.Default.RegisterSqlLogger(database_OnLog);

private　string　sql;
void　database_OnLog(string　logMsg)
{
　　 //保存执行的DbCommand　(sql语句和参数)
　　 sql　+=　"<br　/>"　+　logMsg;
}

and then by executing

DbSession.Default.UnregisterSqlLogger (Database_onlog); To unregister the registered event.

Here is an example of asp.net

DbSession.Default.From<Products>()
　　　　　　　　 .InnerJoin<Suppliers>(Suppliers._.SupplierID　==　Products._.SupplierID)
　　　　　　　　 .Page(10,　2)
　　　　　　　　 .Select(Products._.ProductID,　Products._.ProductName)
　　　　　　　　 .ToDataTable();

The SQL statement that executes the above statement output is as follows:

SELECT　　*　FROM
(　SELECT　　TOP　10　*　FROM
(　SELECT　　TOP　20　[Products].[ProductID],[Products].[ProductName]
FROM　[Products]
INNER　JOIN　[Suppliers]
ON　([Suppliers].[SupplierID]　=　[Products].[SupplierID])
ORDER　BY　[Products].[ProductID]　ASC)　AS　tempIntable
ORDER　BY　[ProductID]　DESC)　AS　tempOuttable
ORDER　BY　[ProductID]　ASC

One more.

Dbsession.default.from<products> (). Where (products._. CategoryID = 2). Tofirst ();

The resulting SQL statement is as follows

Text:
SELECT　TOP　1　*　FROM　[Products]　WHERE　[Products].[CategoryID]　=　@ae2b9c6a112545e5b56fa6dc70f32ac1
Parameters:
@ae2b9c6a112545e5b56fa6dc70f32ac1[Int32]　=　2

This component generated SQL statements can be at a glance, the output of SQL statements is also greatly facilitated debugging.

The next section describes the generation of whereclip (conditions).