# RowSelectionByQuery

The output Concept contains only records that fulfill the SQL condition formulated by the parameters of this operator. This operator is loopable! If applied in a loop, the conditions from the different loops are connected by AND. Every condition consists of a left-hand side, an SQL operator and a right-hand side. Together, these three must form a valid SQL condition. For example, to specify that only records (rows) whose value of attribute `sale` is either or should be selected, the left condition is the BaseAttribute for `sale`, the operator is IN, and the right condition is (50,60).

If this operator is applied in a loop, only the three parameters modelling the condition change from loop to loop, while input and output Concept remain the same.

ParameterName | ObjType | Type | Remarks
TheInputConcept | CON | IN | inherited (same in all loops)
TheLeftCondition | BA | IN | any BA of input concept
TheConditionOperator | V | IN | an SQL operator: <,= ,...
TheRightCondition | V | IN |
TheOutputConcept | CON | OUT | inherited (same in all loops)