Column expressions
Table Column expression
Your Query Instruction can pull data from Vital resources through table column expressions:
| Table | Python DSL | JSON DSL |
|---|---|---|
Activity daily summaryactivity | Activity.col("$1") | { "activity": "$1" } |
Body summarybody | Body.col("$1") | { "body": "$1" } |
Sleep summarysleep | Sleep.col("$1") | { "sleep": "$1" } |
Workout summaryworkout | Workout.col("$1") | { "workout": "$1" } |
Each Table Column expression can select one column (a field) of the table (the Vital resource). You can use multiple Table Column expressions to select multiple columns in the same query.
Cross-table query instruction is not supported — you cannot mix Table Column expressions from different tables in the same query instruction.
Column expressions for summary types, timeseries types as well as lab testing biomarkers are planned to be introduced gradually.
Index Column expression
Each Vital resource has a primary datetime index. Your Query Instruction can reference this datetime index using the special Index Column expression:
| Table | Index | Python DSL | JSON DSL |
|---|---|---|---|
Activity daily summaryactivity | Calendar date | Activity.index() | { "index": "activity" } |
Body summarybody | Measurement datetime | Body.index() | { "index": "body" } |
Sleep summarysleep | Session end datetime | Sleep.index() | { "index": "sleep" } |
Workout summaryworkout | Session start datetime | Workout.index() | { "index": "workout" } |
Group Key Column expression
When your Query Instruction uses the group_by clause, each expression
in the group_by clause creates a temporary Group Key Column (group_key.$OFFSET). These temporary columns are then used to
facilitate the data grouping and aggregation as specified by your Query Instruction.
You can refer to these columns using the special Group Key Column expression:
| Group Key Columns | Python DSL | JSON DSL |
|---|---|---|
| All | group_key("*") | { "group_key": "*" } |
The $N-th key | group_key($N) | { "group_key": $N } |