public VirtualField([NotNull] SelectQuery.Column column)
{
if (column == null)
{
throw new ArgumentNullException("column");
}
Column = column;
}
protected virtual int GetIndex(SelectQuery.Column column)
{
int idx;
if (!ColumnIndexes.TryGetValue(column, out idx))
{
idx = SelectQuery.Select.Add(column);
ColumnIndexes.Add(column, idx);
}
return(idx);
}
static bool CheckColumn(SelectQuery.Column column, ISqlExpression expr, SelectQuery query, bool optimizeValues, bool optimizeColumns)
{
if (expr is SqlField || expr is SelectQuery.Column)
{
return(false);
}
if (expr is SqlValue)
{
return(!optimizeValues && 1.Equals(((SqlValue)expr).Value));
}
if (expr is SqlBinaryExpression)
{
var e = (SqlBinaryExpression)expr;
if (e.Operation == "*" && e.Expr1 is SqlValue)
{
var value = (SqlValue)e.Expr1;
if (value.Value is int && (int)value.Value == -1)
{
return(CheckColumn(column, e.Expr2, query, optimizeValues, optimizeColumns));
}
}
}
var visitor = new QueryVisitor();
if (optimizeColumns &&
QueryVisitor.Find(expr, e => e is SelectQuery || IsAggregationFunction(e)) == null)
{
var n = 0;
var q = query.ParentSelect ?? query;
visitor.VisitAll(q, e => { if (e == column)
{
n++;
}
});
return(n > 2);
}
return(true);
}
void BuildAnyAsCount()
{
SelectQuery.SearchCondition cond;
if (SelectQuery.Select.Columns[0].Expression is SqlFunction)
{
var func = (SqlFunction)SelectQuery.Select.Columns[0].Expression;
cond = (SelectQuery.SearchCondition)func.Parameters[0];
}
else
{
cond = (SelectQuery.SearchCondition)SelectQuery.Select.Columns[0].Expression;
}
var exist = ((SelectQuery.Predicate.FuncLike)cond.Conditions[0].Predicate).Function;
var query = (SelectQuery)exist.Parameters[0];
_selectColumn = new SelectQuery.Column(SelectQuery, new SqlExpression(cond.Conditions[0].IsNot ? "Count(*) = 0" : "Count(*) > 0"), SelectQuery.Select.Columns[0].Alias);
BuildSql(0, query, StringBuilder);
_selectColumn = null;
}
void BuildAnyAsCount()
{
SelectQuery.SearchCondition cond;
if (SelectQuery.Select.Columns[0].Expression is SqlFunction)
{
var func = (SqlFunction)SelectQuery.Select.Columns[0].Expression;
cond = (SelectQuery.SearchCondition)func.Parameters[0];
}
else
{
cond = (SelectQuery.SearchCondition)SelectQuery.Select.Columns[0].Expression;
}
var exist = ((SelectQuery.Predicate.FuncLike)cond.Conditions[0].Predicate).Function;
var query = (SelectQuery)exist.Parameters[0];
_selectColumn = new SelectQuery.Column(SelectQuery, new SqlExpression(cond.Conditions[0].IsNot ? "Count(*) = 0" : "Count(*) > 0"), SelectQuery.Select.Columns[0].Alias);
BuildSql(0, query, StringBuilder);
_selectColumn = null;
}
