使用演示
无论是在新建的程序还是已有的程序中使用NBearLite,步骤都差不多,非常简单。
1、使用NBearLite提供的NBearLite.QueryColumnsGenerator.exe工具从已有数据库(可以是SqlServer、Oracle、MsAccess、MySql、Sqlite或PostgreSql),为表和视图生成强类型查询辅助类,并将生成的代码文件引用到项目工程。
2、在项目中引用NBearLite.dll(该DLL内置了SqlServer、Oracle和MsAccess的DbProvider,如果需要使用MySql、Sqlite或PostgreSql数据库,则还需要引用NBearLite.AdditionalDbProviders.dll)。
3、在项目的Web.config或App.config中的ConnectionStrings配置块中添加connectionstring。添加的语法可以和ADO.NET配置的标准语法一样,也可以简化设置,将providerName设为空(默认为sqlserver), sqlserver, sqlserver2005, msaccess, oracle, mysql,sqlite或postgresql。
4、接着就可以直接在项目中实例化NBearLite.Database对象,并使用Database对象访问数据库了。
具体的使用代码可以参见NBearLite.Test工程。
例如:
在NBearLite.Test工程中,SampleQueryColumnsDefinition.cs文件中保存了由NBearLite.QueryColumnsGenerator.exe工具生成的Northwind数据库的所有表和视图的强类型查询辅助类。
在DatabaseTest.cs文件中,包含了一些查询演示:
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[TestMethod]
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public void TestInsert()
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{
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Assert.AreEqual(1, db.Insert(Northwind.Categories).AddColumn(Northwind.Categories.CategoryName, "test1").Execute());
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Assert.IsTrue(db.Insert(Northwind.Categories).AddColumn(Northwind.Categories.CategoryName, "test1").ExecuteReturnAutoIncrementID(Northwind.Categories.CategoryID) > 1);
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}
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[TestMethod]
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public void TestUpdate()
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{
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Assert.AreEqual(1, db.Insert(Northwind.Categories).AddColumn(Northwind.Categories.CategoryName, "test1").Execute());
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Assert.IsTrue(db.Update(Northwind.Categories).AddColumn(Northwind.Categories.CategoryName, "test1").Where(Northwind.Categories.CategoryName == "test1").Execute() > 0);
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}
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[TestMethod]
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public void TestDelete()
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{
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Assert.AreEqual(1, db.Insert(Northwind.Categories).AddColumn(Northwind.Categories.CategoryName, "test111").Execute());
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Assert.IsTrue(db.Delete(Northwind.Categories).Where(Northwind.Categories.CategoryName == "test111").Execute() > 0);
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}
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[TestMethod]
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public void TestSelect()
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{
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DataSet ds = db.Select(Northwind.Categories).ToDataSet();
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Assert.IsTrue(ds.Tables[0].Rows.Count > 0);
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ds = db.Select(Northwind.Categories, Northwind.Categories.CategoryName).Where(Northwind.Categories.CategoryID > 0).ToDataSet();
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Assert.IsTrue(ds.Tables[0].Rows.Count > 0);
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ds = db.Select(Northwind.Categories, Northwind.Categories.CategoryName).GroupBy(Northwind.Categories.CategoryName).OrderBy(Northwind.Categories.CategoryName.Desc).SetSelectRange(2, 2, Northwind.Categories.CategoryName).ToDataSet();
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ds = db.Select(Northwind.Categories, Northwind.Categories.__Alias("CategoriesAlias").CategoryName).Join(Northwind.Categories, "CategoriesAlias", Northwind.Categories.CategoryID == Northwind.Categories.__Alias("CategoriesAlias").CategoryID).
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SetSelectRange(2, 2, Northwind.Categories.CategoryID).Where(Northwind.Categories.CategoryName.Length > 0 && Northwind.Categories.__Alias("CategoriesAlias").Description != null).
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ToDataSet();
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}
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前三个Test都比较容易理解。TestSelect()中,分别演示了简单查询,分页GroupBy查询和一个自关联Join分页查询。
除了以上演示的代码之外,还可以使用Database.CustomSql()/Database.StoredProcedure()方法查询自定义sql或存储过程。
另外,NBearLite.QueryColumnsGenerator.exe工具本身也是一个使用NBearLite查询数据库的实际的实例程序。
下载
NBearLite_v1.0.0.9 Beta 及中文版NBearLite完全参考手册
修订
7/21 更新至v1.0.0.2 beta - 新增PostgreSql DbProvider,Insert/Update/Select/Delete方法的参数有部分修改,请注意参考以上已更新的的实例代码。
7/22 更新至v1.0.0.3 beta - 修复PostgreSql DbProvider中的Bug。
7/24 更新至v1.0.0.4 beta - 全面支持SqlServer,Oracle,MySql,PostgreSql数据库存储过程调用代码生成(C#/VB.NET)使用示例
7/27 更新至v1.0.0.5 beta - 支持Sub Query查询
Sub Query示例:
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//SELECT * FROM [Products] WHERE ([Products].[CategoryID] IN ((SELECT TOP 10 [Categories].[CategoryID] FROM [Categories] ORDER BY [Categories].[CategoryID])))
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DataSet ds = db.Select(Northwind.Products)
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.Where(Northwind.Products.CategoryID.In
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(
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db.Select(Northwind.Categories, Northwind.Categories.CategoryID).SetSelectRange(10, 0, Northwind.Categories.CategoryID).ToSubQuery())
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)
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.ToDataSet();
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//SELECT * FROM [Products] WHERE ([Products].[CategoryID] = (SELECT TOP 1 [Categories].[CategoryID] FROM [Categories] ORDER BY [Categories].[CategoryID]))
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ds = db.Select(Northwind.Products)
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.Where(Northwind.Products.CategoryID ==
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(
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db.Select(Northwind.Categories, Northwind.Categories.CategoryID).SetSelectRange(1, 0, Northwind.Categories.CategoryID).ToSubQuery())
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)
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.ToDataSet();
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Assert.IsTrue(ds.Tables[0].Rows.Count > 0);
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7/28 更新至v1.0.0.6 beta - 支持Save DataTable/DataRow
Save DataTable/DataRow示例:
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SelectSqlSection selectSection = db.Select(Northwind.Categories)
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.Where(Northwind.Categories.CategoryID == catID)
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.OrderBy(Northwind.Categories.CategoryID.Desc)
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.SetSelectRange(1, 0, Northwind.Categories.CategoryID);
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DataTable dt = selectSection.ToDataSet().Tables[0];
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dt.Rows[0]["CategoryName"] = "modified";
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//save a modified row
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db.Save(selectSection.ToDbCommand(), 10, dt);
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dt.Rows[0]["CategoryName"] = "modified2";
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DataRow newRow = dt.NewRow();
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newRow["CategoryName"] = "new";
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dt.Rows.Add(newRow);
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//save 1 modified row and insert a new row
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db.Save(selectSection.ToDbCommand(), tran, 0, dt.Rows[0], dt.Rows[1]);
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7/29 更新至v1.0.0.7 beta - 发布中文版NBearLite完全参考手册
7/30 更新至v1.0.0.8 beta - 为Stored Procedure包装方法增加带Transaction重载
8/2 更新至v1.0.0.9 beta - 修复NBearLite参考手册某些操作系统打开错误的问题