Test of SQL usage in the browser [WIP]

src/sql-test.md

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+---
+theme: dashboard
+title: SQL Test
+toc: false
+---
+
+# Stromspeicher in Münster
+
+```js
+// import { DuckDBClient } from 'npm:@cmudig/duckdb'
+// import { SummaryTable } from "npm:@observablehq/summary-table"
+
+// LADE die CSV in DUCKDB
+import {utcParse} from "npm:d3-time-format";
+
+const parseDate = utcParse("%Y-%m-%d");
+const coerceRow = function(d) {
+    for (const [key, value] of Object.entries(d)) {
+        if (key.toLowerCase().includes('datum')) {
+            d[key] = parseDate(d[key]);
+        }
+        if (key.toLowerCase().includes('wind')) {
+            delete d[key];
+        }
+    }
+    for (const key of ['Nettonennleistung', 'NutzbareSpeicherkapazitaet', 'Bruttoleistung']) {
+        d[key] = Number(d[key]);
+    }
+    for (const key of ['AnlagenbetreiberMaskedName', 'BiomasseArt', 'BiomasseArtBezeichnung']) {
+        delete d[key];
+    } 
+    return d;
+}
+
+const db = DuckDBClient.of({
+    batteries: FileAttachment('data/marktstammdatenregister-speicher.csv').csv({
+       // delimiter: ',', 
+    }).then((D) => D.map(coerceRow))
+});
+```
+
+
+```js 
+// ## Verfügbare Datenfelder
+// "describeColumns" ist cool, aber brauchen wir nicht, weil "SUMMARIZE" ist noch besser
+// const selectedFields = view(Inputs.table(db.describeColumns({table: "batteries"})))
+```
+
+
+
+
+## Zusammenfassung der Felder
+```js 
+const res = await db.query("SELECT * FROM (SUMMARIZE batteries) WHERE approx_unique > 1");
+const selectedFields = view(Inputs.table(res));
+```
+
+Ausgewwählte Felder:
+```js 
+view(selectedFields )
+```
+
+## Felder mit mehr als 1 Wert
+```js
+function filterF(res) {
+    var fields = []
+    for (const row of res) {
+        if (row.approx_unique > 1) {
+            fields.push(row.column_name)
+        } 
+    } 
+    return fields
+}
+const interesting_fields = filterF(res)
+
+display(interesting_fields)
+```
+
+## Alle Daten
+```js 
+display(Inputs.table(db.query("SELECT " + interesting_fields.join(',') + " FROM batteries")));
+```
+test