[DMDB] Sorting, selection, projection, aggregation

2026-07-27 21:29:09 +02:00 · 2026-07-17 16:08:58 +02:00
parent 653a807848
commit 89009ef7d3
13 changed files with 161 additions and 6 deletions
@@ -5,8 +5,7 @@ which corresponds to $\Pi_{\texttt{I}}(\sigma_{\texttt{C}} \texttt{T})$.
 We can set \texttt{I = *} if we want to return all columns for a table.
 To rename, we can set \texttt{I = Column as Name, Column2 as Name2}, etc

-% TODO: Make RA an acronym, too
-\inlinetheorem Every SPJR \acrshort{RA} expression can be written in \texttt{SELECT ... FROM ... WHERE ...} form:
+\inlinetheorem Every SPJR \acrshort{ra} expression can be written in \texttt{SELECT ... FROM ... WHERE ...} form:
 \begin{tables}{lll}{Operation   & Notation                   & SQL}
              Selection         & $\sigma_c(R)$              & \texttt{SELECT * FROM R WHERE c;}              \\
              Projection        & $\Pi_{A_1, \ldots, A_n} R$ & \texttt{SELECT A1, \ldots, An FROM R;}         \\