protected override Expression VisitMethodCall(MethodCallExpression methodExp)
{
if (methodExp.Method.Name == "OrderByDescending" || methodExp.Method.Name == "ThenByDescending")
{
OrderByFields.Clear();
OrderBy = "DESC";
Expression obj = this.Visit(((LambdaExpression)methodExp.Arguments[1]).Body);
OrderByFieldsStack.Insert(0, OrderByFields.ToString().TrimEnd(','));
OrderByFields.Clear();
if (methodExp.Arguments[0].NodeType == ExpressionType.Call)
{
this.Visit(methodExp.Arguments[0]);
}
return(methodExp);
}
else if (methodExp.Method.Name == "OrderBy" || methodExp.Method.Name == "ThenBy")
{
OrderByFields.Clear();
OrderBy = "ASC";
Expression obj = this.Visit(((LambdaExpression)methodExp.Arguments[1]).Body);
OrderByFieldsStack.Insert(0, OrderByFields.ToString().TrimEnd(','));
OrderByFields.Clear();
if (methodExp.Arguments[0].NodeType == ExpressionType.Call)
{
this.Visit(methodExp.Arguments[0]);
}
return(methodExp);
}
else
{
Expression obj = this.Visit(methodExp.Object);
object result = Expression.Lambda(methodExp).Compile().DynamicInvoke();
var r = Expression.Constant(result, methodExp.Method.ReturnType);
this.Visit(r);
return(r);
}
throw new NotSupportedException(string.Format("lambda表达式不支持使用此'{0}'方法", methodExp.Method.Name));
}
/// <summary>
/// 多表连查分页
/// </summary>
/// <typeparam name="TModel"></typeparam>
/// <param name="page"></param>
/// <returns></returns>
public PageDataSource <TModel> GetPage <TModel>(PageFilter page)
{
List <JoinRelation> tables = new List <JoinRelation>();
SqlBuilder.AppendFormat(" SELECT {0} FROM {1}", SelectFields.ToString().TrimEnd(','), JoinRelations[0].LeftTable);
if (WithAlias)
{
SqlBuilder.AppendFormat(" AS {0}", JoinRelations[0].LeftTableAlias);
}
foreach (JoinRelation j in JoinRelations)
{
if (j.JoinType == JoinType.Outer)
{
SqlBuilder.Append(" LEFT OUTER JOIN ");
}
else
{
SqlBuilder.Append(" INNER JOIN ");
}
if (WithAlias)
{
if (tables.Count(m => m.LeftTableAlias == j.RightTableAlias || m.RightTableAlias == j.RightTableAlias) == 0)
{
SqlBuilder.AppendFormat("{0} AS {1}", j.RightTable, j.RightTableAlias);
tables.Add(j);
}
else
{
SqlBuilder.AppendFormat("{0} AS {1}", j.LeftTable, j.LeftTableAlias);
tables.Add(j);
}
}
else
{
if (tables.Count(m => m.LeftTable == j.RightTable || m.RightTable == j.RightTable) == 0)
{
SqlBuilder.Append(j.RightTable);
tables.Add(j);
}
else
{
SqlBuilder.Append(j.LeftTable);
tables.Add(j);
}
}
SqlBuilder.AppendFormat(" ON {0}", j.OnSql.TrimEnd("AND".ToCharArray()));
}
if (WhereClause.Length > 0)
{
SqlBuilder.AppendFormat(" WHERE {0}", WhereClause.ToString().Trim().TrimEnd("AND".ToCharArray()));
}
if (GroupByFields.Length > 0)
{
SqlBuilder.AppendFormat(" GROUP BY {0}", GroupByFields.ToString().Trim().TrimEnd(','));
}
if (OrderByFields.Length > 0)
{
page.OrderText = OrderByFields.ToString().Trim().TrimEnd(',');
}
//开始组装sql
//开始组装sql
PageDataSource <TModel> result = DbContext.GetPage <TModel>(SqlBuilder.ToString(), page, Parameters.ToArray());
if (this.IsAutoDisposeDbContext)
{
DbContext.Dispose();
}
return(result);
}
/// <summary>
/// 返回数量
/// </summary>
/// <returns></returns>
public int GetCount()
{
List <JoinRelation> tables = new List <JoinRelation>();
SqlBuilder.AppendFormat(" SELECT COUNT(1) AS CT FROM {0}", JoinRelations[0].LeftTable);
if (WithAlias)
{
SqlBuilder.AppendFormat(" AS {0}", JoinRelations[0].LeftTableAlias);
}
foreach (JoinRelation j in JoinRelations)
{
if (j.JoinType == JoinType.Outer)
{
SqlBuilder.Append(" LEFT OUTER JOIN ");
}
else
{
SqlBuilder.Append(" INNER JOIN ");
}
if (WithAlias)
{
if (tables.Count(m => m.LeftTableAlias == j.RightTableAlias || m.RightTableAlias == j.RightTableAlias) == 0)
{
SqlBuilder.AppendFormat("{0} AS {1}", j.RightTable, j.RightTableAlias);
tables.Add(j);
}
else
{
SqlBuilder.AppendFormat("{0} AS {1}", j.LeftTable, j.LeftTableAlias);
tables.Add(j);
}
}
else
{
if (tables.Count(m => m.LeftTable == j.RightTable || m.RightTable == j.RightTable) == 0)
{
SqlBuilder.Append(j.RightTable);
tables.Add(j);
}
else
{
SqlBuilder.Append(j.LeftTable);
tables.Add(j);
}
}
SqlBuilder.AppendFormat(" ON {0}", j.OnSql.TrimEnd("AND".ToCharArray()));
}
if (WhereClause.Length > 0)
{
SqlBuilder.AppendFormat(" WHERE {0}", WhereClause.ToString().Trim().TrimEnd("AND".ToCharArray()));
}
if (GroupByFields.Length > 0)
{
SqlBuilder.AppendFormat(" GROUP BY {0}", GroupByFields.ToString().Trim().TrimEnd(','));
}
if (OrderByFields.Length > 0)
{
SqlBuilder.AppendFormat(" ORDER BY {0}", OrderByFields.ToString().Trim().TrimEnd(','));
}
//开始组装sql
int result = DbContext.GetSingle <int>(SqlBuilder.ToString(), Parameters.ToArray());
if (this.IsAutoDisposeDbContext)
{
DbContext.Dispose();
}
return(result);
}