/// <summary>
/// Makes a copy of this SelectExpression.
/// </summary>
/// <param name="alias"> The alias. </param>
/// <returns>
/// A copy of this SelectExpression.
/// </returns>
public virtual SelectExpression Clone([CanBeNull] string alias = null)
{
var selectExpression
= new SelectExpression(_querySqlGeneratorFactory, _queryCompilationContext)
{
_limit = _limit,
_offset = _offset,
_isDistinct = _isDistinct,
_subqueryDepth = _subqueryDepth,
IsProjectStar = IsProjectStar,
Predicate = Predicate
};
if (alias != null)
{
selectExpression.Alias = _queryCompilationContext.CreateUniqueTableAlias(alias);
}
selectExpression._projection.AddRange(_projection);
selectExpression.AddTables(_tables);
selectExpression.AddToOrderBy(_orderBy);
return(selectExpression);
}
/// <summary>
/// Creates a subquery based on this SelectExpression and makes that table the single entry in
/// <see cref="Tables" />. Clears all other top-level aspects of this SelectExpression.
/// </summary>
/// <returns>
/// A SelectExpression.
/// </returns>
public virtual SelectExpression PushDownSubquery()
{
_subqueryDepth++;
var subquery = new SelectExpression(_querySqlGeneratorFactory, _queryCompilationContext, SystemAliasPrefix);
var columnAliasCounter = 0;
foreach (var expression in _projection)
{
var aliasExpression = expression as AliasExpression;
if (aliasExpression != null)
{
var columnExpression = aliasExpression.TryGetColumnExpression();
if (columnExpression != null &&
subquery._projection.OfType <AliasExpression>()
.Any(ae => (ae.Alias ?? ae.TryGetColumnExpression()?.Name) == (aliasExpression.Alias ?? columnExpression.Name)))
{
aliasExpression.Alias = "c" + columnAliasCounter++;
}
}
else
{
aliasExpression = new AliasExpression("c" + columnAliasCounter++, expression);
}
subquery._projection.Add(aliasExpression);
}
subquery.AddTables(_tables);
subquery.AddToOrderBy(_orderBy);
subquery.Predicate = Predicate;
subquery._limit = _limit;
subquery._offset = _offset;
subquery._isDistinct = _isDistinct;
subquery._subqueryDepth = _subqueryDepth;
subquery.ProjectStarAlias = ProjectStarAlias;
subquery.IsProjectStar = IsProjectStar || !subquery._projection.Any();
_limit = null;
_offset = null;
_isDistinct = false;
ProjectStarAlias = null;
Predicate = null;
ClearTables();
ClearProjection();
ClearOrderBy();
AddTable(subquery, createUniqueAlias: false);
ProjectStarAlias = subquery.Alias;
return(subquery);
}
public virtual SelectExpression Clone([NotNull] string alias)
{
Check.NotNull(alias, nameof(alias));
var selectExpression
= new SelectExpression(_querySqlGeneratorFactory, alias)
{
_limit = _limit,
_offset = _offset,
_isDistinct = _isDistinct,
_subqueryDepth = _subqueryDepth,
IsProjectStar = IsProjectStar,
Predicate = Predicate
};
selectExpression._projection.AddRange(_projection);
selectExpression.AddTables(_tables);
selectExpression.AddToOrderBy(_orderBy);
return(selectExpression);
}
public virtual SelectExpression Clone([NotNull] string alias)
{
Check.NotNull(alias, nameof(alias));
var selectExpression
= new SelectExpression(_querySqlGeneratorFactory, _queryCompilationContext, alias)
{
_limit = _limit,
_offset = _offset,
_isDistinct = _isDistinct,
_subqueryDepth = _subqueryDepth,
IsProjectStar = IsProjectStar,
Predicate = Predicate
};
selectExpression._projection.AddRange(_projection);
selectExpression.AddTables(_tables);
selectExpression.AddToOrderBy(_orderBy);
return selectExpression;
}
public virtual SelectExpression PushDownSubquery()
{
_subqueryDepth++;
var subquery = new SelectExpression(_querySqlGeneratorFactory, _queryCompilationContext, SystemAliasPrefix);
var columnAliasCounter = 0;
foreach (var expression in _projection)
{
var aliasExpression = expression as AliasExpression;
if (aliasExpression != null)
{
var columnExpression = aliasExpression.TryGetColumnExpression();
if (columnExpression != null
&& subquery._projection.OfType<AliasExpression>()
.Any(ae => ae.TryGetColumnExpression()?.Name == columnExpression.Name))
{
aliasExpression.Alias = "c" + columnAliasCounter++;
}
}
else
{
aliasExpression = new AliasExpression("c" + columnAliasCounter++, expression);
}
subquery._projection.Add(aliasExpression);
}
subquery.AddTables(_tables);
subquery.AddToOrderBy(_orderBy);
subquery.Predicate = Predicate;
subquery._limit = _limit;
subquery._offset = _offset;
subquery._isDistinct = _isDistinct;
subquery._subqueryDepth = _subqueryDepth;
subquery.IsProjectStar = IsProjectStar || !subquery._projection.Any();
_limit = null;
_offset = null;
_isDistinct = false;
Predicate = null;
ClearTables();
ClearProjection();
ClearOrderBy();
AddTable(subquery, createUniqueAlias: false);
return subquery;
}
/// <summary>
/// Makes a copy of this SelectExpression.
/// </summary>
/// <param name="alias"> The alias. </param>
/// <returns>
/// A copy of this SelectExpression.
/// </returns>
public virtual SelectExpression Clone([CanBeNull] string alias = null)
{
var selectExpression
= new SelectExpression(_querySqlGeneratorFactory, _queryCompilationContext)
{
_limit = _limit,
_offset = _offset,
_isDistinct = _isDistinct,
_subqueryDepth = _subqueryDepth,
IsProjectStar = IsProjectStar,
Predicate = Predicate
};
if (alias != null)
{
selectExpression.Alias = _queryCompilationContext.CreateUniqueTableAlias(alias);
}
selectExpression._projection.AddRange(_projection);
selectExpression.AddTables(_tables);
selectExpression.AddToOrderBy(_orderBy);
return selectExpression;
}
/// <summary>
/// Creates a subquery based on this SelectExpression and makes that table the single entry in
/// <see cref="Tables" />. Clears all other top-level aspects of this SelectExpression.
/// </summary>
/// <returns>
/// A SelectExpression.
/// </returns>
public virtual SelectExpression PushDownSubquery()
{
_subqueryDepth++;
var subquery = new SelectExpression(Dependencies, _queryCompilationContext, SystemAliasPrefix);
var columnAliasCounter = 0;
foreach (var expression in _projection)
{
var aliasExpression = expression as AliasExpression;
if (aliasExpression != null)
{
var columnExpression = aliasExpression.TryGetColumnExpression();
if ((columnExpression != null &&
subquery._projection.OfType <AliasExpression>()
.Any(ae => (ae.Alias ?? ae.TryGetColumnExpression()?.Name) == (aliasExpression.Alias ?? columnExpression.Name))) ||
columnExpression == null)
{
aliasExpression.Alias = "c" + columnAliasCounter++;
}
}
else
{
aliasExpression = new AliasExpression("c" + columnAliasCounter++, expression);
}
subquery._projection.Add(aliasExpression);
}
subquery.AddTables(_tables);
subquery.AddToOrderBy(_orderBy);
subquery.Predicate = Predicate;
subquery._limit = _limit;
subquery._offset = _offset;
subquery._isDistinct = _isDistinct;
subquery._subqueryDepth = _subqueryDepth;
subquery.ProjectStarTable = ProjectStarTable;
subquery.IsProjectStar = IsProjectStar || !subquery._projection.Any();
_limit = null;
_offset = null;
_isDistinct = false;
ProjectStarTable = null;
Predicate = null;
ClearTables();
ClearProjection();
ClearOrderBy();
_tables.Add(subquery);
ProjectStarTable = subquery;
foreach (var ordering in subquery.OrderBy)
{
var expression = ordering.Expression;
var aliasExpression = expression as AliasExpression;
if (aliasExpression != null)
{
if (aliasExpression.Alias != null)
{
_orderBy.Add(
new Ordering(
new ColumnExpression(aliasExpression.Alias, aliasExpression.Type, subquery),
ordering.OrderingDirection));
}
else
{
var newExpression = UpdateColumnExpression(aliasExpression.Expression, subquery);
_orderBy.Add(
new Ordering(
new AliasExpression(newExpression), ordering.OrderingDirection));
}
}
else
{
if (!subquery.IsProjectStar)
{
subquery.AddToProjection(expression);
}
var newExpression = UpdateColumnExpression(expression, subquery);
_orderBy.Add(
new Ordering(
new AliasExpression(newExpression), ordering.OrderingDirection));
}
}
if (subquery.Limit == null &&
subquery.Offset == null)
{
subquery.ClearOrderBy();
}
return(subquery);
}
