SqlDataAdapter.FillSchema(DataTable)方法填充数据表的主键和约束

本文转载自http://www.csframework.com/archive/2/arc-2-20110730-1768.htm

使用SqlDataAdapter.FillSchema方法可以填充数据表的主键和约束，但无法填充主外键，如DataTable.ParentRelations和DataTable.ChildRelations的数据。

自动填充主键和约束有两种方法：

1. adp.MissingSchemaAction
= MissingSchemaAction.AddWithKey

2. dt1
= adp.FillSchema(data, SchemaType.Mapped);//填充结构

具体代码如下：

public class FillDataWithSchema
    {
        private SqlConnection _Connection = null;
 
        public FillDataWithSchema()
        {
            string S = @"Server=.\SQLExpress;Database=D:\MY SOURCECODE\CSHARP\CSFRAMEWORKTESTDB\CSFrameworkTestDB.MDF;Integrated Security=True;";
            _Connection = new SqlConnection(S);
        }
 
        public void FillData()
        {
            DataTable data = new DataTable();
            SqlDataAdapter adp = new SqlDataAdapter("SELECT * FROM tb_MyUser", _Connection);
            adp.Fill(data);//填充数据
            ShowSchema(data);//显示结构
 
            //AddWithKey: 自动填充数据表结构,如：主键和限制
            //预设值Add,不填充结构
            adp.MissingSchemaAction = MissingSchemaAction.AddWithKey;//Default Value is: Add
 
            adp.Fill(data);//填充数据和结构,如：主键和限制
            ShowSchema(data);//显示结构
 
            DataTable dt1;
 
            dt1 = adp.FillSchema(data, SchemaType.Mapped);//填充结构
            ShowSchema(dt1);//显示结构
 
            _Connection.Close();
 
            Console.ReadLine();
        }
 
        /// <summary>
        /// 显示表结构
        /// </summary>
        /// <param name="data"></param>
        private void ShowSchema(DataTable data)
        {
            Console.WriteLine("Rows:" + data.Rows.Count);
 
            //主键
            Console.WriteLine("PrimaryKey:" + data.PrimaryKey.Length.ToString());
            foreach (DataColumn c in data.PrimaryKey)
                Console.WriteLine(c.ColumnName);
 
            //约束
            Console.WriteLine("Constraints:" + data.Constraints.Count.ToString());
            foreach (Constraint c in data.Constraints)
                Console.WriteLine(c.ConstraintName);
 
            //无法获取主外键主联定义
            Console.WriteLine("ParentRelations:" + data.ParentRelations.Count.ToString());
            Console.WriteLine("ChildRelations:" + data.ChildRelations.Count.ToString());
 
            Console.WriteLine("------------------------------------------------");
        }
    }

点击运行，结果如下图