public override SqlExpressions.IAliasedExpression Visit(SqlExpressions.SelectStatement item)
{
SqlExpressions.SelectStatement oldItem = item;
var columnToReplaceWith = this.columnToReplaceWith;
if (this.columnToReplaceWith != null && inFrom && item.Top == 0)
{
replacedSelect = item = (SqlExpressions.SelectStatement)updater.Update(item, new SqlExpressions.IAliasedExpression[] { columnToReplaceWith }, item.From, item.Where, item.OrderBy, item.Alias);
}
this.columnToReplaceWith = null;
int n = 0;
foreach (var column in oldItem.Columns)
{
n++;
this.columnToReplaceWith = column;
}
if (n > 1 ||
this.columnToReplaceWith == null ||
this.columnToReplaceWith.DbExpressionType != SqlExpressions.DbExpressionType.Aggregate)
{
if (this.columnToReplaceWith != null)
{
if (this.columnToReplaceWith.DbExpressionType == SqlExpressions.DbExpressionType.Column)
{
var column = this.columnToReplaceWith as SqlExpressions.ComplexColumnExpression;
if (column != null && ((SqlExpressions.IDbExpression)column.Expression).DbExpressionType != SqlExpressions.DbExpressionType.Value)
{
this.columnToReplaceWith = null;
replacedSelect = null;
item = oldItem;
}
else if (this.columnToReplaceWith.DbExpressionType != SqlExpressions.DbExpressionType.Aggregate)
{
this.columnToReplaceWith = null;
replacedSelect = null;
item = oldItem;
}
}
else
{
this.columnToReplaceWith = null;
replacedSelect = null;
item = oldItem;
}
}
}
var result = base.Visit(item);
this.columnToReplaceWith = columnToReplaceWith;
if (replacedSelect != null && item != replacedSelect)
{
result = replacedSelect;
replacedSelect = null;
}
return result;
}
public override SqlExpressions.IAliasedExpression Visit(SqlExpressions.SelectStatement item)
{
bool wasInSelect = inSelect;
if (!inSelect)
{
int n = 0;
foreach (var column in item.Columns)
{
n++;
lastColumn = column;
}
if (n == 1 && (lastColumn.DbExpressionType == SqlExpressions.DbExpressionType.Aggregate || lastColumn.DbExpressionType == DbExpressionType.Function || lastColumn.DbExpressionType == DbExpressionType.Column && ((ColumnExpression)lastColumn).Alias == null))
{
inSelect = true;
if (item.Where != null || item.From.Count != 1 || item.From[0].DbExpressionType != DbExpressionType.Select || ((SelectStatement)item.From[0]).Top > 0)
lastColumn = null;
item = (SqlExpressions.SelectStatement)base.Visit(item);
if (lastColumn != null)
return item.From[0];
inSelect = wasInSelect;
}
return item;
}
else
{
List<SqlExpressions.IAliasedExpression> columns = new List<SqlExpressions.IAliasedExpression>();
foreach (var column in item.Columns)
{
if (column.DbExpressionType == SqlExpressions.DbExpressionType.Column && column is SqlExpressions.ComplexColumnExpression)
columns.Add(column);
}
if (columns.Count <= 1)
{
if (columns.Count == 1 && (((SqlExpressions.IDbExpression)((SqlExpressions.ComplexColumnExpression)columns[0]).Expression).DbExpressionType == SqlExpressions.DbExpressionType.Case ||
((SqlExpressions.IDbExpression)((SqlExpressions.ComplexColumnExpression)columns[0]).Expression).DbExpressionType == SqlExpressions.DbExpressionType.Value))
{
columns.RemoveAt(0);
}
if (lastColumn != null)
columns.Add(lastColumn);
else
columns.Add(new ComplexColumnExpression(null, new Constant(1, System.Data.DbType.Int32), "a"));
}
return updater.Update(item, columns, item.From, item.Where, item.OrderBy, item.Alias);
}
}
