Use view for read_paruqt

Author: datadavev

tutorials/parquet.qmd

@@ -9,25 +9,28 @@ Let's query Eric's parquet file using duckdb+parquet
 //| output: false
 //
 
-// Create a DuckDB instance
-db = DuckDBClient.of()
+parquet_path = 'https://storage.googleapis.com/opencontext-parquet/oc_isamples_pqg.parquet';
 
-// Set the Parquet file path
-parquet_path = 'https://storage.googleapis.com/opencontext-parquet/oc_isamples_pqg.parquet'
+// Create a DuckDB instance
+db = {
+  const instance = await DuckDBClient.of();
+  await instance.query(`create view nodes as select * from read_parquet('${parquet_path}')`)
+  return instance;
+}
 
 row_count = {
-  const result = await db.queryRow(`select count(*) as n from read_parquet('${parquet_path}');`);
+  const result = await db.queryRow(`select count(*) as n from nodes;`);
   return result.n;
 }
 
 results = {
-  const data = await db.query(`SELECT COUNT(*) as count, otype FROM read_parquet('${parquet_path}') GROUP BY otype ORDER BY count DESC`);
+  const data = await db.query(`SELECT COUNT(*) as count, otype FROM nodes GROUP BY otype ORDER BY count DESC`);
   document.getElementById("loading_1").hidden = true;
   return Inputs.table(data);
 }
 
 rows1k = {
-  const data = await db.query(`SELECT row_id, pid, otype, label FROM read_parquet('${parquet_path}') limit 1000`);
+  const data = await db.query(`SELECT row_id, pid, otype, label FROM nodes limit 1000`);
   document.getElementById("loading_2").hidden = true;
   return Inputs.table(data);
 }

tutorials/parquet_cesium.qmd

@@ -24,17 +24,22 @@ This page renders points from an iSamples parquet file on cesium using point pri
 ```{ojs}
 //| output: false
 Cesium.Ion.defaultAccessToken = 'eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJqdGkiOiIwNzk3NjkyMy1iNGI1LTRkN2UtODRiMy04OTYwYWE0N2M3ZTkiLCJpZCI6Njk1MTcsImlhdCI6MTYzMzU0MTQ3N30.e70dpNzOCDRLDGxRguQCC-tRzGzA-23Xgno5lNgCeB4';
+```
 
+```{ojs}
+//| echo: false
 viewof parquet_path = Inputs.text({label:"Source", value:"https://storage.googleapis.com/opencontext-parquet/oc_isamples_pqg.parquet", width:"100%", submit:true});
 ```
 
 ```{ojs}
 //| code-fold: true
-// Import Observable's libraries
-import {DuckDBClient} from "@observablehq/duckdb"
 
 // Create a DuckDB instance
-db = DuckDBClient.of();
+db = {
+  const instance = await DuckDBClient.of();
+  await instance.query(`create view nodes as select * from read_parquet('${parquet_path}')`)
+  return instance;
+}
 
 
 async function loadData(query, params=[], waiting_id=null) {
@@ -62,9 +67,13 @@ async function loadData(query, params=[], waiting_id=null) {
 
 locations = {
     // get the content form the parquet file
-    const query = `SELECT row_id, pid, latitude, longitude FROM read_parquet('${parquet_path}') WHERE otype='GeospatialCoordLocation'`;
+    const query = `SELECT pid, latitude, longitude FROM nodes WHERE otype='GeospatialCoordLocation'`;
     const data = await loadData(query, [], "loading_1");
 
+    // Clear the existing PointPrimitiveCollection
+    content.points.removeAll();
+    //content.points = new Cesium.PointPrimitiveCollection();
+
     // create point primitives for cesium display
     const scalar = new Cesium.NearFarScalar(1.5e2, 2, 8.0e6, 0.2);
     const color = Cesium.Color.PINK;
@@ -78,7 +87,6 @@ locations = {
                 row.latitude,   //latitude
                 0,//randomCoordinateJitter(10.0, 10.0), //elevation, m
             ),
-            row_id: row.row_id,
             pixelSize: point_size,
             color: color,
             scaleByDistance: scalar,
@@ -109,7 +117,7 @@ function createShowPrimitive(viewer) {
         // If selectPoint is valid and no currently selected point
         if (Cesium.defined(selectPoint) && selectPoint.hasOwnProperty("primitive")) {
             //console.log(`showPrimitiveId ${selectPoint.id}`);
-            const carto = Cesium.Cartographic.fromCartesian(selectPoint.primitive.position)
+            //const carto = Cesium.Cartographic.fromCartesian(selectPoint.primitive.position)
             viewer.pointLabel.position = selectPoint.primitive.position;
             viewer.pointLabel.label.show = true;
             //viewer.pointLabel.label.text = `id:${selectPoint.id}, ${carto}`;
@@ -180,11 +188,19 @@ async function getGeoRecord(pid) {
     if (pid === null || pid ==="" || pid == "unset") {
         return "unset";
     }
-    const q = `SELECT row_id, pid, otype, latitude, longitude FROM read_parquet('${parquet_path}') WHERE otype='GeospatialCoordLocation' AND pid=?`;
+    const q = `SELECT row_id, pid, otype, latitude, longitude FROM nodes WHERE otype='GeospatialCoordLocation' AND pid=?`;
     const result = await db.queryRow(q, [pid]);
     return result;
 }
 
+async function locationUsedBy(rowid){
+    if (rowid === undefined || rowid === null) {
+        return [];
+    }
+    const q = `select pid, otype from nodes where row_id in (select nodes.s from nodes where list_contains(nodes.o, ?));`;
+    return db.query(q, [rowid]);
+}
+
 mutable clickedPointId = "unset";
 selectedGeoRecord = await getGeoRecord(clickedPointId);
 
@@ -229,3 +245,4 @@ ${JSON.stringify(selectedGeoRecord, null, 2)}
 `
 ```
 
+