private void Prune(IPlainSelect selectBody)
{
if (selectBody.SelItems.Select(s => s.Exp).OfType <CountAllFunction>().Any() && !(selectBody.FromItem is SubSelect))
{
return;
}
var expressionsToCheck = selectBody.SelItems.Select(s => s.Exp).ToList();
if (selectBody.WhereExp != null)
{
expressionsToCheck.Add(selectBody.WhereExp);
}
var usedAliases = (from selectExp in expressionsToCheck
from column in selectExp.Descendants().OfType <Column>()
select column.Table.Alias.Name).Distinct();
for (int i = selectBody.Joins.Count - 1; i >= 0; i--)
{
var join = selectBody.Joins[i];
if (join.RightItem is Table table && !usedAliases.Contains(table.Alias.Name))
{
selectBody.Joins.RemoveAt(i);
}
}
if (selectBody.FromItem is SubSelect subSelect)
{
Prune(subSelect.SelectBody);
}
}
private void Complete(IPlainSelect body, SelectContext context)
{
if (body.SelItems[0].Exp == null)
{
var table = body.FromItem as Table;
body.SelItems[0].Exp = CreateColumn(table);
}
Prune(body);
}
private static string Print(ISelectItem selectItem, IPlainSelect selectBody)
{
var expression = PrintExpression((dynamic)selectItem.Exp, selectBody);
if (selectItem.Alias != null)
{
expression += " " + selectItem.Alias.Name;
}
return(expression);
}
private static string PrintExpression(Column column, IPlainSelect selectBody)
{
var prefix = column.Table?.Alias?.Name;
if (prefix != null)
{
prefix += ".";
}
return(prefix + column.Name);
}
/// <summary>
/// Adds the given element to the collection
/// </summary>
/// <param name="item">The item to add</param>
public override void Add(IModelElement item)
{
if ((this._parent.SelectBody == null))
{
IPlainSelect selectBodyCasted = item.As <IPlainSelect>();
if ((selectBodyCasted != null))
{
this._parent.SelectBody = selectBodyCasted;
return;
}
}
}
private static string PrintExpression(CountAllFunction countAll, IPlainSelect selectBody)
{
if (selectBody.Joins.Count > 0)
{
var lastJoin = selectBody.Joins.Last();
if (lastJoin.OnExp is EqualsToExpression equals && equals.RightExp is Column targetColumn)
{
return($"COUNT({targetColumn.Table.Alias.Name}.{targetColumn.Name})");
}
}
return("COUNT(*)");
}
public static string Print(IPlainSelect selectBody)
{
var resultBuilder = new StringBuilder();
resultBuilder.Append($"SELECT {string.Join(", ", selectBody.SelItems.Select(sel => Print(sel, selectBody)))}");
if (selectBody.FromItem != null)
{
resultBuilder.Append($" FROM {PrintFrom((dynamic)selectBody.FromItem)}");
}
foreach (var join in selectBody.Joins)
{
resultBuilder.Append($" {(join.Left.GetValueOrDefault() ? "LEFT" : "INNER")} JOIN {PrintFrom((dynamic)join.RightItem)} ON {PrintExpression((dynamic)join.OnExp, selectBody)}");
}
if (selectBody.WhereExp != null)
{
resultBuilder.Append($" WHERE {PrintExpression((dynamic)selectBody.WhereExp, selectBody)}");
}
if (selectBody.GroupBy != null)
{
resultBuilder.Append($" GROUP BY {string.Join(", ", selectBody.GroupBy.GroupByExps.Select(exp => PrintExpression((dynamic)exp, selectBody)))}");
}
return(resultBuilder.ToString());
}
private static string PrintExpression(AndExpression andExpression, IPlainSelect selectBody)
{
return($"{PrintExpression((dynamic)andExpression.LeftExp, selectBody)} and {PrintExpression((dynamic)andExpression.RightExp, selectBody)}");
}
private static string PrintExpression(GreaterThanExpression greaterThan, IPlainSelect selectBody)
{
return($"{PrintExpression((dynamic)greaterThan.LeftExp, selectBody)} > {PrintExpression((dynamic)greaterThan.RightExp, selectBody)}");
}
private static string PrintExpression(LongValue longValue, IPlainSelect selectBody)
{
return(longValue.Value.ToString());
}
private static string PrintExpression(StringValue stringValue, IPlainSelect selectBody)
{
return(stringValue.Value);
}
private static string PrintExpression(EqualsToExpression equalsTo, IPlainSelect selectBody)
{
return($"{PrintExpression((dynamic)equalsTo.LeftExp, selectBody)} = {PrintExpression((dynamic)equalsTo.RightExp, selectBody)}");
}
