Microorm. Net (4) Table. Query ()-Where

Microorm. Net homepage:

Http://code.google.com/p/micro-orm-net/

Overview of the microorm. Net series directories:

Http://www.cnblogs.com/mapserver/archive/2012/04/07/2436129.html

 

This article demonstrates the query of microorm. net. Please refer to the table. Query () API documentation:

// ---------------------- Part 1 ---------------------- query where (expression criteria) query select (Params mathe [] maths) query select (Params column [] columns) query join (Table jointable, expression on) query innerjoin (Table jointable, expression on) query leftjoin (Table jointable, expression on) query leftouterjoin (Table jointable, expression on) query rightjoin (Table jointable, expression on) query rightouterjoin (Table jointable, expression on) query orderby (Params column [] columns) query orderbyasc (Params column [] columnsquery orderbydesc (Params column [] columns) query groupby (Params column [] columns) query having (expression criteria) query SKIP (INT skip) query take (INT take) query distinct () // ---------------------- Part 2 ---------------------- dynamic first () t first <t> () Dynamic last () t last <t> () ilist tolist () Dynamic [] toarray () ilist <t> tolist <t> () T [] toarray <t> ()

The preceding API is divided into two parts. The first part returns the query object, and the second part executes the SQL statement to the database to return the query result.

 

Where:

db.OrderDatail.Query()        .Where(db.OrderDetail.OrderId == "001")        db.OrderDatail.Query()        .Where(db.OrderDetail.OrderId == "001" && db.OrderDetail.Qty > 0)        db.OrderDatail.Query()        .Where(db.OrderDetail.OrderId == "001" && (db.OrderDetail.Qty > 0 || db.OrderDetail.OrderDetailId == "001")

 

Microorm. Net also supports table aliases. Even if the table alias is defined, the table alias can be used or not used in the where method expression.

The where method can be executed multiple times.

db.OrderDatail.As("od").Query() //table alias        .Where(db.od.OrderId == "001")        .Where(db.OrderDetail.Qty > 0)

 

The expressions of the where method also support like, isnull, and isnotnull.

db.OrderDatail.As("od").Query()        .Where(db.od.ProductId.IsNotNull())        .Where(db.od.ProductId.Like("CA%") 

 

The following shows how to execute an SQL statement to a database:

var od = db.OrderDetail.Query()                .Where(db.OrderDetail.OrderId == "001")                .First();

The generated SQL statement is as follows:

exec sp_executesql N'SELECT TOP 1 [_#0_].* FROM [dbo].[OrderDetail] [_#0_] WHERE [_#0_].[OrderId] = @p0 ',N'@p0 nvarchar(3)',@p0=N'001'

 

More:

var od1 = db.OrderDetail.Query()    .Where(db.OrderDetail.OrderId == "001")    .First<OrderDetail>();var od2 = db.OrderDetail.Query()    .Where(db.OrderDetail.OrderId == "001")    .Last();OrderDetail od3 = db.OrderDetail.Query()    .Where(db.OrderDetail.OrderId == "001")    .Last<OrderDetail>();IList ods1 = db.OrderDetail.Query()        .Where(db.OrderDetail.OrderId == "001")        .ToList(); dynamic[] ods2 = db.OrderDetail.Query()        .Where(db.OrderDetail.OrderId == "001")        .ToArray();IList<OrderDetail> ods3 = db.OrderDetail.Query()        .Where(db.OrderDetail.OrderId == "001")        .ToList<OrderDetail>();OrderDetail[] ods4 = db.OrderDetail.Query()        .Where(db.OrderDetail.OrderId == "001")        .ToArray<OrderDetail>();