This is the sixteenth part of the SQLxD series. For your convenience you can find other parts in the table of contents in Part 1 – XML Transformation Today we implement various aggregates. Let’s start with the interface: We can see that the aggregate returns one cell for whole relation. You might wonder why is … Continue reading SQLxD Part 16 — Aggregates

This is the fifteenth part of the SQLxD series. For your convenience you can find other parts in the table of contents in Part 1 – XML Transformation Last time we implemented grouping, today we focus on ordering. These two operations are very similar. First, we need to know which column we use for sorting … Continue reading SQLxD Part 15 — Ordering

This is the fourteenth part of the SQLxD series. For your convenience you can find other parts in the table of contents in Part 1 – XML Transformation Today we implement grouping. Since we can group in multiple ways, we need to have grouping sets: Grouping set is just a set of columns which we … Continue reading SQLxD Part 14 — Grouping

This is the thirtieth part of the SQLxD series. For your convenience you can find other parts in the table of contents in Part 1 – XML Transformation We mentioned the natural join a few times and it finally the part when we implement it. Here we go: First, we compare guid collection lengths. This … Continue reading SQLxD Part 13 — Natural join

This is the twelfth part of the SQLxD series. For your convenience you can find other parts in the table of contents in Part 1 – XML Transformation Let’s implement tests for joins: They are rather straightforward. Next time we are going to implement natural join.