Extract table values
Deephaven tables have methods to extract values from tables into the native programming language. Generally, this isn't necessary for Deephaven queries but may be useful for debugging and logging purposes, and other specific use cases such as using listeners.
table.getColumnSource()
The general syntax to extract a specific value from a table is value = table.getColumnSource("column").get(index)
.
The getColumnSource
method allows you to convert a column to a ColumnSource
object.
result = newTable(
intCol("Integers", 1, 2, 3, 4, 5)
)
columnSource = result.getColumnSource("Integers")
println columnSource
- Log
Once you've gotten your column source, you can use its methods. For extracting a table value, you use the get
method to retrieve the value of the column at the given index.
println columnSource.get(2)
- Log
table.columnIterator()
In cases where you want to loop over all the values in a column, you can use the columnIterator
method. This method returns an iterator for all the values in the column.
iterator = result.columnIterator("Integers")
while (iterator.hasNext()) {
println iterator.next()
}
- Log