From bf8dbb13873c471f2b9b1c95fb8b7d0a58c9c076 Mon Sep 17 00:00:00 2001 From: Gregor Kleen Date: Sun, 8 Nov 2015 00:21:20 +0000 Subject: =?UTF-8?q?Datenbanken=20=C2=AD=20Blatt=2004?= MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit --- ws2015/datenbanksysteme/blaetter/04/abgabe.md | 15 +++++++++++++++ 1 file changed, 15 insertions(+) create mode 100644 ws2015/datenbanksysteme/blaetter/04/abgabe.md (limited to 'ws2015') diff --git a/ws2015/datenbanksysteme/blaetter/04/abgabe.md b/ws2015/datenbanksysteme/blaetter/04/abgabe.md new file mode 100644 index 0000000..708a249 --- /dev/null +++ b/ws2015/datenbanksysteme/blaetter/04/abgabe.md @@ -0,0 +1,15 @@ +--- +header-includes: + - \usepackage{amsmath} + - \usepackage{amssymb} +--- + +# Natural Join + +Zu $\land$. + +# Anfragen in relationaler Algebra + +a) $\pi_{\texttt{P.pname}}(\sigma_{\texttt{P.ort} = \text{Berlin}}(\texttt{P}))$ +b) $\pi_{\texttt{T.tnr}} \left ( \sigma_{\texttt{L.lname} = \text{Meier}} \left ( \texttt{L} \bowtie \texttt{LTP} \texttt{T} \right ) \right )$ +c) $\pi_{\texttt{T.tname}}(\sigma_{\texttt{P.ort} = \text{Berlin}}(\texttt{P} \bowtie \texttt{LTP} \bowtie \texttt{T}))$ -- cgit v1.2.3