|
public ChangeWhereAndColumns ( |
||
| where | ||
| columns | IReadOnlyList |
|
| forUpdate | bool | |
| 리턴 | ||
protected override Expression VisitSelect(SqlSelectExpression selectExpression)
{
List<SqlColumnDeclaration> newColumns = null;
for (var i = 0; i < selectExpression.Columns.Count; i++)
{
var column = selectExpression.Columns[i];
var visitedColumnExpression = this.Visit(column.Expression);
if (visitedColumnExpression.Type.GetUnwrappedNullableType() == typeof(bool) && !(visitedColumnExpression is BitBooleanExpression))
{
if (newColumns == null)
{
newColumns = new List<SqlColumnDeclaration>(selectExpression.Columns.Take(i));
}
var newColumnExpression = BitBooleanExpression.Coerce(visitedColumnExpression);
var newColumnDeclaration = new SqlColumnDeclaration(column.Name, newColumnExpression);
newColumns.Add(newColumnDeclaration);
}
else if (visitedColumnExpression != column.Expression)
{
if (newColumns == null)
{
newColumns = new List<SqlColumnDeclaration>(selectExpression.Columns.Take(i));
}
newColumns.Add(column.ReplaceExpression(visitedColumnExpression));
}
else if (newColumns != null)
{
newColumns.Add(column);
}
}
var where = this.Visit(selectExpression.Where);
if ((where is BitBooleanExpression))
{
where = Expression.Equal(where, Expression.Constant(true));
}
if (where != selectExpression.Where)
{
if (newColumns != null)
{
return selectExpression.ChangeWhereAndColumns(where, new ReadOnlyList<SqlColumnDeclaration>(newColumns));
}
else
{
return selectExpression.ChangeWhere(where);
}
}
else if (newColumns != null)
{
return selectExpression.ChangeColumns(newColumns, true);
}
else
{
return base.VisitSelect(selectExpression);
}
}