MrPowers opened a new issue, #159:
URL: https://github.com/apache/sedona-db/issues/159
SedonaDB currently has SQL and Python interfaces.
Here's how you can get the number of rows in a SedonaDB DataFrame with
Python:
```python
df.count()
```
Here's how you can get the number of rows with SQL:
```python
df.to_view("earth_cities")
sd.sql("select count(*) from earth_cities").show()
```
Maybe this isn't the best example because `df.count()` returns an integer
and `sd.sql()` returns a DataFrame, but you get the point.
Other functionality can only be expressed via the SQL API. Here is an
example:
```python
nyc_bbox_wkt = (
"POLYGON((-74.2591 40.4774, -74.2591 40.9176, -73.7004 40.9176, -73.7004
40.4774, -74.2591 40.4774))"
)
sd.sql(f"""
SELECT
id,
height,
num_floors,
roof_shape,
ST_Centroid(geometry) as centroid
FROM
buildings
WHERE
is_underground = FALSE
AND height IS NOT NULL
AND height > 20
AND ST_Intersects(geometry,
ST_SetSRID(ST_GeomFromText('{nyc_bbox_wkt}'), 4326))
LIMIT 5;
""").show()
```
Some libraries, like Spark, have both SQL and Python interfaces. Here's how
this logic would be expressed in PySpark:
```python
result = (buildings
.where(col("is_underground") == False)
.where(col("height").isNotNull())
.where(col("height") > 20)
.where(ST_Intersects(
col("geometry"),
ST_SetSRID(ST_GeomFromText(lit(nyc_bbox_wkt)), lit(4326))
))
.select(
"id",
"height",
"num_floors",
"roof_shape",
ST_Centroid(col("geometry")).alias("centroid")
)
.limit(5)
.show()
)
```
Polars syntax would be something like this (I think, feel free to chime in
here Polars experts):
```python
result = (
buildings
.filter(
(pl.col("is_underground") == False) &
(pl.col("height").is_not_null()) &
(pl.col("height") > 20) &
pl.st_intersects(
pl.col("geometry"),
pl.st_set_srid(pl.st_geom_from_text(pl.lit(nyc_bbox_wkt)),
pl.lit(4326))
)
)
.select([
pl.col("id"),
pl.col("height"),
pl.col("num_floors"),
pl.col("roof_shape"),
pl.st_centroid(pl.col("geometry")).alias("centroid")
])
.limit(5)
)
```
Should we expose a Python interface like this? If so, what syntax would
users like the best?
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