dataset詳細(xì)用法(最全面)

1、C#:DataSet用法詳解第1頁DataSet用法詳細(xì)用法詳細(xì)一、特點(diǎn)介紹一、特點(diǎn)介紹1、處理脫機(jī)數(shù)據(jù)，在多層應(yīng)用程序中很有用。2、可以在任何時(shí)候查看DataSet中任意行的內(nèi)容，允許修改查詢結(jié)果的方法。3、處理分級(jí)數(shù)據(jù)4、緩存更改5、XML的完整性：DataSet對(duì)象和XML文檔幾乎是可互換的。二、使用介紹二、使用介紹1、創(chuàng)建、創(chuàng)建DataSet對(duì)象：對(duì)象：DataSetds=newDataSet(“DataSetName“)2、查

2、看調(diào)用、查看調(diào)用SqlDataAdapter.Fill創(chuàng)建的結(jié)構(gòu)創(chuàng)建的結(jié)構(gòu)da.Fill(ds“ders“)DataTabletbl=ds.Table[0]feach(DataColumncolintbl.Columns)Console.WriteLine(col.ColumnName)3、查看、查看SqlDataAdapter返回的數(shù)據(jù)返回的數(shù)據(jù)①DataRowDataRow對(duì)象對(duì)象DataTabletbl=ds.Table[0]Da

3、taRowrow=tbl.Row[0]Console.WriteLine(ros[“derID“])②檢查存儲(chǔ)在②檢查存儲(chǔ)在DataRowDataRow中的數(shù)據(jù)中的數(shù)據(jù)DataTabletbl=row.Tablefeach(DataColumncolintbl.Columns)Console.WriteLine(row[col])③檢查③檢查DatTableDatTable中的中的DataRowDataRow對(duì)象對(duì)象feach(Data

4、Rowrowintbl.Rows)DisplayRow(row)4、校驗(yàn)、校驗(yàn)DataSet中的數(shù)據(jù)中的數(shù)據(jù)①校驗(yàn)①校驗(yàn)DataColumnDataColumn的屬性：的屬性：ReadOnlyAllowDBNullMaxLengthUnique②DataTableDataTable對(duì)象的對(duì)象的ConstrainsConstrains集合：集合：UiqueConstraintsPrimarykeyFeignkeyConstraints通常

5、不必刻意去創(chuàng)建FeignkeyConstraints因?yàn)楫?dāng)在DataSet的兩個(gè)DataTable對(duì)象之間創(chuàng)建關(guān)系時(shí)會(huì)創(chuàng)建一個(gè)。③用③用SqlDataAdapter.FillSqlDataAdapter.Fill模式來檢索模式信息模式來檢索模式信息5、編寫代碼創(chuàng)建、編寫代碼創(chuàng)建DataTable對(duì)象對(duì)象①創(chuàng)建①創(chuàng)建DataTableDataTable對(duì)象對(duì)象:DataTabletbl=newDataTable(“TableName“)②

6、將②將DataTableDataTable添加到添加到DataSetDataSet對(duì)象的對(duì)象的TableTable集合集合DataSetds=newDataSet()DataTabletbl=newDataTable(“Customers“)ds.Tables.Add(tbl)DataSetds=newDataSet()DataTabletbl=ds.Tables.Add(“Customers“)C#:DataSet用法詳解第3頁if(

7、rowCustomer==null)沒有查找客戶elserowCustomer.BeginEdit()rowCustomer[“CompanyName“]=“NewCompanyName“rowCustomer[“ContactName“]=“NewContactName“rowCustomer.EndEdit()null表示不修改該列的數(shù)據(jù)obejct[]aCustomer=null“NewCompanyName““NewContac

8、tName“nullDataRowrowCustomerrowCustomer=ds.Tables[“Customers“].Rows.Find(“ALFKI“)rowCustomer.ItemArray=aCustomer③處理③處理DataRowDataRow的空值的空值查看是否為空DataRowrowCustomerrowCustomer=ds.Tables[“Customers“].Rows.Find(“ALFKI“)if(ro

9、wCustomer.IsNull(“Phone“))Console.WriteLine(“ItsNull“)elseConsole.WriteLine(“ItsnotNull“)賦予空值rowCustomer[“Phone“]=DBNull.Value④刪除④刪除DataRowDataRowDataRowrowCustomerrowCustomer=ds.Tables[“Customers“].Rows.Find(“ALFKI“)row

10、Customer.()⑤清除⑤清除DataRowDataRowDataRowrowCustomer=ds.Tables[“Customers“].Rows.Find(“ALFKI“)rowCustomer.ItemArray=aCustomerda.Tables[“Customers“].Remove(rowCustomer)或者ds.Tables[“Customers“].RemoveAt(intIndex)⑥使用⑥使用DataRow

11、.RowStateDataRow.RowState屬性屬性：UnchangedDetachedAddedModifieddUnchangedDetachedAddedModifieddprivatevoidDemonstrateRowState()RunafunctiontocreateaDataTablewithonecolumn.DataTablemyTable=MakeTable()DataRowmyRowCreateanewDa