entity-framework – 实体框架 – 删除Oracle 10g中的实体{由于
发布时间:2021-01-13 09:09:26  所属栏目:百科  来源:网络整理 
            导读:我尝试在Oracle 10g上的Entity Framework中使用Repository模式.我简化了我的代码: 这是SQL代码: -- Create tablecreate table TESTTABLE( MODULE_UNIQUE_ID VARCHAR2(32) not null,PANEL_STATUS VARCHAR2(8) not null)tablespace SYSTEM pctfree 10 pctuse
                
                
                
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                         我尝试在Oracle 10g上的Entity Framework中使用Repository模式.我简化了我的代码: 这是SQL代码: -- Create table
create table TESTTABLE
(
  MODULE_UNIQUE_ID VARCHAR2(32) not null,PANEL_STATUS     VARCHAR2(8) not null
)
tablespace SYSTEM
  pctfree 10
  pctused 40
  initrans 1
  maxtrans 255
  storage
  (
    initial 64K
    minextents 1
    maxextents unlimited
  );
-- Create/Recreate primary,unique and foreign key constraints 
alter table TESTTABLE
  add constraint TESTTABLE_PK_01 unique (MODULE_UNIQUE_ID)
  using index 
  tablespace SYSTEM
  pctfree 10
  initrans 2
  maxtrans 255
  storage
  (
    initial 64K
    minextents 1
    maxextents unlimited
  ); 
 我创建了简单的存储库类: public interface IRepository<TEntity,TCtx>
{
    TCtx Session { get;}
    void Add(TEntity entity);
    void AddOrAttach(TEntity entity);
    void Delete(TEntity entity);
    int Save();
    TEntity SelectByKey(string colName,string key);
}
public class Repository<TEntity,TCtx> : IRepository<TEntity,TCtx>,IDisposable
    where TEntity : EntityObject
    where TCtx : ObjectContext
{
    #region Private fields
    private TCtx _ctx;
    private string _keyProperty = "ID";
    public int Save()
    {
        return _ctx.SaveChanges();
    }
   public TEntity SelectByKey(string colName,string key)
    {
        KeyProperty = colName;
        // First we define the parameter that we are going to use the clause.
        var xParam = Expression.Parameter(typeof(TEntity),typeof(TEntity).Name);
        MemberExpression leftExpr = Expression.Property(xParam,KeyProperty);
        Expression rightExpr = Expression.Constant(key);
        BinaryExpression binaryExpr = Expression.Equal(leftExpr,rightExpr);
        //Create Lambda Expression for the selection
        Expression<Func<TEntity,bool>> lambdaExpr = Expression.Lambda<Func<TEntity,bool>>
            (binaryExpr,new ParameterExpression[] { xParam });
        //Searching ....
        //IList<TEntity> resultCollection = ((IRepository<TEntity,TCtx>)this).SelectAll(new Specification<TEntity>(lambdaExpr));
        //if (null != resultCollection && resultCollection.Count() > 0)
        //{
        //    //return valid single result
        //    return resultCollection.First();
        /                         | 
                  

