Forum Discussion
Tim Curwick
Sep 19, 2017Copper Contributor
Get scalar value from table
Using the new OMS Log Analytics query language, how do I get a scalar value out of a table?
That is, what is the equivalent of this TSQL query, presuming Table1 has a single row:
Select @ScalarVar = Column1 from Table1
Tim,
You're looking for toscalar(). For a slightly more advanced example of how to use it (together with makeset() and in()), check out the last section of our aggregations tutorial.
To pseudocode your example, you'd be looking at something like:
let myDateTime = toscalar(Table1 | summarize max(TimeGenerated));
Table 2
| where TimeGenerated between ((myDateTime - 5m) .. (myDateTime + 5m))
| ...
- Hi I am not very familiar with SQL but I think you are probably are looking for let statement: https://docs.loganalytics.io/docs/Language-Reference/Query-statements/Let-statement
- Tim CurwickCopper Contributor
Stanislav,
I have some understanding of the let statement.
In all of the examples, you can use a let statement with a query to store a table result, or with a scalar expression to store a scalar result.
How do I get, store and use scalar result that comes from a table query?
For example, I need to run one query that gets and stores the datetime from Column1 of Table1 of a particular single record, so that I can use that scalar value in subsequent queries.
- Evgeny Ternovsky
Microsoft
Tim,
You're looking for toscalar(). For a slightly more advanced example of how to use it (together with makeset() and in()), check out the last section of our aggregations tutorial.
To pseudocode your example, you'd be looking at something like:
let myDateTime = toscalar(Table1 | summarize max(TimeGenerated));
Table 2
| where TimeGenerated between ((myDateTime - 5m) .. (myDateTime + 5m))
| ...