public static int?TryGetOrAddColumn(DbSqlQueryExpression sqlQuery, DbExpression exp, string addDefaultAlias = UtilConstants.DefaultColumnAlias)
{
if (exp == null)
{
return(null);
}
List <DbColumnSegment> columnList = sqlQuery.ColumnSegments;
DbColumnSegment columnSeg = null;
int?ordinal = null;
for (int i = 0; i < columnList.Count; i++)
{
var item = columnList[i];
if (DbExpressionEqualityComparer.EqualsCompare(item.Body, exp))
{
ordinal = i;
columnSeg = item;
break;
}
}
if (ordinal == null)
{
string alias = Utils.GenerateUniqueColumnAlias(sqlQuery, addDefaultAlias);
columnSeg = new DbColumnSegment(exp, alias);
columnList.Add(columnSeg);
ordinal = columnList.Count - 1;
}
return(ordinal.Value);
}
public static DbExpression TryGetOrAddNullChecking(DbSqlQueryExpression sqlQuery, DbTable table, DbExpression exp)
{
if (exp == null)
{
return(null);
}
List <DbColumnSegment> columnList = sqlQuery.ColumnSegments;
DbColumnSegment columnSeg = null;
columnSeg = columnList.Where(a => DbExpressionEqualityComparer.EqualsCompare(a.Body, exp)).FirstOrDefault();
if (columnSeg == null)
{
string alias = Utils.GenerateUniqueColumnAlias(sqlQuery);
columnSeg = new DbColumnSegment(exp, alias);
columnList.Add(columnSeg);
}
DbColumnAccessExpression cae = new DbColumnAccessExpression(columnSeg.Body.Type, table, columnSeg.Alias);
return(cae);
}