public QueryCommand <TEntity> Where(Expression <Func <TEntity, bool> > exp)
{
var retData = new ExpressionAnalyzer(exp).GetAnalysisResult();
_creator.CreateWhere(retData);
_params = retData.ParamList;
_table = retData.Table;
return(this);
}
/// <summary>
/// 解析表信息
/// </summary>
/// <param name="exp"></param>
/// <param name="refTable">引用表</param>
private void AnalysisTables(Expression exp, AnalysisTable refTable = null)
{
var className = exp.GetType().Name;
switch (className)
{
case "PropertyExpression":
case "FieldExpression":
var mberExp = exp as MemberExpression;
if (IsDefaultType(mberExp.Type))
{
AnalysisTables(mberExp.Expression);
break;
}
var _tampTab = GetTableByRName(_resultData.Table, mberExp.Member.Name);
if (_tampTab == null)
{
_tampTab = new AnalysisTable()
{
RName = mberExp.Member.Name,
Name = mberExp.Type.Name,
TableType = mberExp.Type
};
AnalysisTables(mberExp.Expression, _tampTab);
}
if (refTable != null)
{
_tampTab.LeftJoins.Add(refTable);
}
break;
case "TypedParameterExpression":
//命名参数表达式
var texp = exp as ParameterExpression;
if (!IsDefaultType(texp.Type))
{
if (null == _resultData.Table)
{
_resultData.Table = new AnalysisTable()
{
RName = _argName,
Name = texp.Type.Name,
TableType = texp.Type
};
}
if (refTable != null)
{
_resultData.Table.LeftJoins.Add(refTable);
}
}
break;
default:
break;
}
}
private void AppendLeftJoinTables(AnalysisTable anlyTable, TableInfo tableInfo, StringBuilder sb)
{
///添加关系表信息
foreach (var item in anlyTable.LeftJoins)
{
var _foreignRef = GetForeignReference(tableInfo, item.RName);
if (string.IsNullOrEmpty(_foreignRef.Key))
{
// throw new BusinessException(BusinessRes.WhitoutThisForeignReference);
throw new Exception("foreign key");
}
sb.AppendFormat(" LEFT JOIN [{0}] AS [{1}] ON [{1}].{2}=[{3}].{4} ", item.Name, item.RName, _foreignRef.Value.PrimaryKey, anlyTable.RName, _foreignRef.Key);
AppendLeftJoinTables(item, _foreignRef.Value, sb);
}
}
public virtual void CreateFrom(AnalysisTable anlyTable, TableInfo tableInfo)
{
if (null == anlyTable)
{
throw new ArgumentNullException("anlyTable");
}
//默认排序信息
if (string.IsNullOrEmpty(Debris.Order))
{
Debris.Order = string.Format("[{0}].{1} {2}", anlyTable.RName, tableInfo.PrimaryKey, System.Enum.GetName(typeof(OrderTypeEnum), OrderTypeEnum.ASC));
}
StringBuilder sb = new StringBuilder();
sb.AppendFormat("[{0}] AS [{1}]", anlyTable.Name, anlyTable.RName);
AppendLeftJoinTables(anlyTable, tableInfo, sb);
Debris.From = sb.ToString();
}
/// <summary>
/// 遍历树，深度优先
/// </summary>
/// <param name="table"></param>
/// <param name="rName"></param>
/// <returns></returns>
private AnalysisTable GetTableByRName(AnalysisTable table, string rName)
{
var _tempTable = table;
if (_tempTable.RName == rName)
{
return(_tempTable);
}
foreach (var item in _tempTable.LeftJoins)
{
_tempTable = GetTableByRName(item, rName);
if (_tempTable != null)
{
return(_tempTable);
}
}
return(null);
}
public ExpressionAnalyzer(LambdaExpression exp, AnalysisTable table = null)
: this()
{
if (table != null)
{
_resultData.Table = table;
}
if (exp != null)
{
AppendParams(GetChildValue(exp.Body), _params);
foreach (var item in exp.Parameters)
{
AnalysisTables(item);
}
AnalysisExpression(exp.Body, true);
}
}
