Data Mining is one of the emerging fields in research. Preparing a Data set is one of the important tasks in Data Mining. To analyze data efficiently, Data Mining systems are widely using datasets with columns in horizontal tabular layout. Building a datasets for analysis is normally a most time consuming task. Existing SQL aggregations have limitation to build data sets because they return one column for aggregated group using group functions. A method is developed to generate SQL code to return aggregated columns in a horizontal tabular layout, returning a set of numbers instead of one number per row. This new class of functions are called horizontal aggregations. This method is termed as BY-LOGIC. SQL code generator generates automatic SQL code for producing horizontal aggregation. A fundamental method to evaluate horizontal aggregation called CASE (exploiting the case programming construct) is used. Basically, there are three parameters available namely: grouping, sub-grouping and aggregating fields for creating horizontal aggregation. Query evaluation shows that CASE method responses faster than BY-LOGIC method.