# Querying data

### **Execute a query**

```r
library("redivis")

# Execute any SQL query and read the results
query <- redivis$query("SELECT 1 + 1 AS two, 'foo' AS bar")
query$to_tibble()
# 	two	bar
# 0	2	foo

# The query can reference any table on Redivis 
query <- redivis.query("
    SELECT * 
    FROM demo.iris_species.iris 
    WHERE SepalLengthCm > 5
")
query$to_tibble()
# 	Id	SepalLengthCm	SepalWidthCm	PetalLengthCm	PetalWidthCm	Species
# 0	33	5.2	        4.1	        1.5	        0.1	        Iris-setosa
# ...

# Other methods to read data:
# query$to_arrow_batch_reader()
# query$to_arrow_dataset()
# query$to_arrow_dataset()
# query$to_data_frame()
# query$to_data_table()
# query$to_sf_tibble()
```

### **Using dbplyr**

```r
con <- redivis$connect_dbi()
tbl(con, "demo.ghcn_daily_weather_data.stations") |> filter(latitude > 0) |> collect()

# or, scope to a dataset / workflow:

con <- redivis$dataset("demo.ghcn_daily_weather_data")$connect_dbi()
tbl(con, "stations") |> filter(latitude > 0) |> collect()
```

### **Execute a scoped query**

```r
library("redivis")

# Perform a query on the Demo CMS Medicare data. 
# Table at https://redivis.com/datasets/349j-7phs91amz/tables

# To simplify table references, execute a query scoped to a dataset or workflow
dataset <- redivis$organization("Demo")$dataset("CMS 2014 Medicare Data")
query <- dataset.query("
    SELECT 
        hospice_providers.name, 
        inpatient_charges.drg_definition
    -- The tables inpatient_chargers, hospice_providers are assumed to be 
    -- within the scoped dataset
    FROM inpatient_charges
    INNER JOIN hospice_providers 
        ON hospice_providers.provider_id = inpatient_charges.provider_id
")

query$to_tibble()
```

### Run a query within a Redivis notebook

<pre class="language-r"><code class="lang-r"><strong># In a notebook, all queries are scoped to the current workflow.
</strong># Additionally, the notebooks source table can simply be referenced as _source_
query &#x3C;- redivis$query("SELECT * FROM _source_ LIMIT 10")
</code></pre>


---

# Agent Instructions: Querying This Documentation

If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question.

Perform an HTTP GET request on the current page URL with the `ask` query parameter:

```
GET https://docs.redivis.com/api/client-libraries/redivis-r/examples/querying-data.md?ask=<question>
```

The question should be specific, self-contained, and written in natural language.
The response will contain a direct answer to the question and relevant excerpts and sources from the documentation.

Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.