private void ParenthesizeExpressionIfNeeded(Predicate e, SqlBuilder result)
{
if (IsComplexExpression(e))
{
result.Append("(");
result.Append(e.Accept(this));
result.Append(")");
}
else
{
result.Append(e.Accept(this));
}
}
private SqlSelectStatement VisitFilterExpression(PredicateBinding input, Predicate predicate, bool negatePredicate)
{
Symbol fromSymbol;
var result = VisitInputExpression(input.Predicate, input.VariableName, input.VariableType, out fromSymbol);
if (!IsCompatible(result, PredicateType.Filter))
{
result = CreateNewSelectStatement(result, input.VariableName, input.VariableType, out fromSymbol);
}
selectStatementStack.Push(result);
symbolTable.EnterScope();
AddFromSymbol(result, input.VariableName, fromSymbol);
if (negatePredicate)
{
result.Where.Append("NOT (");
}
result.Where.Append(predicate.Accept(this));
if (negatePredicate)
{
result.Where.Append(")");
}
symbolTable.ExitScope();
selectStatementStack.Pop();
return(result);
}
private SqlSelectStatement VisitInputExpression(Predicate inputPredicate, string inputVarName, TypeUsage inputVarType, out Symbol fromSymbol)
{
SqlSelectStatement result;
var sqlFragment = inputPredicate.Accept(this);
result = sqlFragment as SqlSelectStatement;
if (result == null)
{
result = new SqlSelectStatement();
WrapNonQueryExtent(result, sqlFragment, inputPredicate.PredicateType);
}
if (result.FromExtents.Count == 0)
{
fromSymbol = new Symbol(inputVarName, inputVarType);
}
else if (result.FromExtents.Count == 1)
{
fromSymbol = result.FromExtents[0];
}
else
{
var joinSymbol = new JoinSymbol(inputVarName, inputVarType, result.FromExtents);
joinSymbol.FlattenedExtentList = result.AllJoinExtents;
fromSymbol = joinSymbol;
result.FromExtents.Clear();
result.FromExtents.Add(fromSymbol);
}
return(result);
}
private SqlSelectStatement VisitExpressionEnsureSqlStatement(Predicate e, bool addDefaultColumns, bool markAllDefaultColumnsAsUsed)
{
SqlSelectStatement result;
switch (e.PredicateType)
{
case PredicateType.Project:
case PredicateType.Filter:
case PredicateType.GroupBy:
case PredicateType.Sort:
result = e.Accept(this) as SqlSelectStatement;
break;
default:
Symbol fromSymbol;
var inputVarName = "c";
symbolTable.EnterScope();
TypeUsage type = null;
switch (e.PredicateType)
{
case PredicateType.Scan:
case PredicateType.CrossJoin:
case PredicateType.FullOuterJoin:
case PredicateType.InnerJoin:
case PredicateType.LeftOuterJoin:
case PredicateType.CrossApply:
case PredicateType.OuterApply:
type = e.ResultType.GetElementTypeUsage();
break;
default:
type = TypeUsage.Create(e.ResultType.EdmType);
break;
}
result = VisitInputExpression(e, inputVarName, type, out fromSymbol);
AddFromSymbol(result, inputVarName, fromSymbol);
symbolTable.ExitScope();
break;
}
if (addDefaultColumns && result.Select.IsEmpty)
{
var defaultColumns = AddDefaultColumns(result);
if (markAllDefaultColumnsAsUsed)
{
foreach (var symbol in defaultColumns)
{
optionalColumnUsageManager.MarkAsUsed(symbol);
}
}
}
return(result);
}
protected virtual string GetWhereClause(PropertyColumnMap mapping, Predicate predicate, QueryParameters queryParams)
{
var sqlWhere = predicate?.Accept(
new PostgresPredicateVisitor(
Schema,
queryParams));
return(sqlWhere != null
? $"WHERE { sqlWhere }"
: string.Empty);
}
