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Rule-based Row Filter

Like its cousin, the standard Row Filter, the Rule-based Row Filter is used to dynamically remove records from a table. However, unlike the Row Filter, the Rule-based Row Filter allows you to create multiple logical expressions to fine-tune your filtering.

The cofiguration menu displays these panes:
- Column List: A list of all column names in the table
- Flow Variable List: A list of all flow variables attached in the stream
- Functions: A list of logical functions and operators available
- Description: A written explanation of what a selected function does and how to use it
- Expression: Where you will enter the filter expression


Writing Expressions
At first, writing expressions in the Rule-based Row Filter may seem confusing. For example, the expression

$StateName$ LIKE "North*" => TRUE

says to return a TRUE value for any StateName value that matches the wildcard expression "North*". Any record that does not match this expression will automatically have a FALSE value and not pass through the node.

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You may also write multiple expressions across multple lines. Each line is treated independently, so you can think of them as a logical OR construct.

$StateName$ = "Florida" => TRUE
$StateName$ = "New Mexico" => TRUE

will pass records that match either Florida OR New Mexico, but no others.

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Each rule is comprised of two parts:
- The condition, known as the antecedent. This is the left-hand side of the expression.
- The outcome, known as the consequent. This is the right-hand side of the expression after the => symbol.

Rule-based Row Filter Like its cousin, the standard Row Filter, the Rule-based Row Filter is used todynamically remove records from a table. However, unlike the Row Filter, the Rule-based Row Filter allows you to create multiple logical expressions to fine-tune yourfiltering.The cofiguration menu displays these panes:- Column List: A list of all column names in the table- Flow Variable List: A list of all flow variables attached in the stream- Functions: A list of logical functions and operators available- Description: A written explanation of what a selected function does and how to use it- Expression: Where you will enter the filter expressionWriting ExpressionsAt first, writing expressions in the Rule-based Row Filter may seem confusing. Forexample, the expression$StateName$ LIKE "North*" => TRUEsays to return a TRUE value for any StateName value that matches the wildcardexpression "North*". Any record that does not match this expression will automaticallyhave a FALSE value and not pass through the node.----------------You may also write multiple expressions across multple lines. Each line is treatedindependently, so you can think of them as a logical OR construct.$StateName$ = "Florida" => TRUE$StateName$ = "New Mexico" => TRUEwill pass records that match either Florida OR New Mexico, but no others.----------------Each rule is comprised of two parts:- The condition, known as the antecedent. This is the left-hand side of the expression.- The outcome, known as the consequent. This is the right-hand side of the expressionafter the => symbol. Include rows that match a single, simple expression.Any StateName value that matches the wildcard"North*" is assigned a TRUE value and passedthrough the node. Include rows that match one of two independentexpressions. A more complex expression. Include rows that matchthe regular expression (StateName has a string) ANDwhose population is less than 5,000,000. Notice thatthe rule is written on only one line. You may also chose to exclude TRUE matches ratherthan inverting the logic of each rule. Night Heron Data, 2023 Input some dataSimpleexpressionMulti lineexpressionMore complexlogical expressionSame as above, but exclude matches Table Creator Rule-basedRow Filter Rule-basedRow Filter Rule-basedRow Filter Rule-basedRow Filter Rule-based Row Filter Like its cousin, the standard Row Filter, the Rule-based Row Filter is used todynamically remove records from a table. However, unlike the Row Filter, the Rule-based Row Filter allows you to create multiple logical expressions to fine-tune yourfiltering.The cofiguration menu displays these panes:- Column List: A list of all column names in the table- Flow Variable List: A list of all flow variables attached in the stream- Functions: A list of logical functions and operators available- Description: A written explanation of what a selected function does and how to use it- Expression: Where you will enter the filter expressionWriting ExpressionsAt first, writing expressions in the Rule-based Row Filter may seem confusing. Forexample, the expression$StateName$ LIKE "North*" => TRUEsays to return a TRUE value for any StateName value that matches the wildcardexpression "North*". Any record that does not match this expression will automaticallyhave a FALSE value and not pass through the node.----------------You may also write multiple expressions across multple lines. Each line is treatedindependently, so you can think of them as a logical OR construct.$StateName$ = "Florida" => TRUE$StateName$ = "New Mexico" => TRUEwill pass records that match either Florida OR New Mexico, but no others.----------------Each rule is comprised of two parts:- The condition, known as the antecedent. This is the left-hand side of the expression.- The outcome, known as the consequent. This is the right-hand side of the expressionafter the => symbol. Include rows that match a single, simple expression.Any StateName value that matches the wildcard"North*" is assigned a TRUE value and passedthrough the node. Include rows that match one of two independentexpressions. A more complex expression. Include rows that matchthe regular expression (StateName has a string) ANDwhose population is less than 5,000,000. Notice thatthe rule is written on only one line. You may also chose to exclude TRUE matches ratherthan inverting the logic of each rule. Night Heron Data, 2023 Input some dataSimpleexpressionMulti lineexpressionMore complexlogical expressionSame as above, but exclude matches Table Creator Rule-basedRow Filter Rule-basedRow Filter Rule-basedRow Filter Rule-basedRow Filter

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