Functions Introduction

Gathr provides different kind of functions like Date, Lookup, String, Math, Array and Miscellaneous functions. Using these functions, you can directly apply computations on the dataset columns and get desired result.

The functions takes columns and/or literals as arguments.

In order to pass column “A” of a dataset “D” as a function argument, pass for example

@{column.D.A}

There are some exceptions where you need to pass the column name directly.

Following are the functions that take the column name directly.

expr(A)

rename_column(A)

In order to pass a “string literal” as argument to function pass it in double quotes for example

“IST”

In order to pass a “number literal” to a function, pass it as it is.

For example, 2 or 1.345

If we have a dataset named schemaName having a string/date/timestamp column date holding the value 2009-03-01 for a particular row, then

add_months@{column.schemaName.date},2) will return 2009-05-01

Note:

All the examples presented in this guide have column values instead of the entire expression i.e. @{column.schemaName.columnName}

add_months@{column.schemaName.date},2) will return 2009-05-01

add_months is a function, @{column.schemaName.date} is an expression and 2009-03-01 is the value of the expression.

add_months(@{column.schemaName.date},2) will be shown as:

add_months(2009-03-01,2)