Replacing values with Iterations

Many thanks. I really appreciate your support.

Hello AlienSx I am studying your sulution. The first you gave is pretty clear. I am struggling a little bit with your second as I did not understand this part:

transformations = List.Transform(columns_list, (name) => {name, (x) => Record.FieldOrDefault(repl, x, x)}),

Here my questions:

1. columns_list is input argument, so it is fine.

2. What is the meaning of the function (name)?

3. What are the arguments passed to this function?

4. In general I am always struggling with this type of construction:

(x) => if Record.Field(x, condition_column) = condition_value
then Record.TransformFields(x, transformations)
else x

As I did not understand what are the values that the argument x assumes.

Could you help me?

Many thanks.

2. List.Transform requires a function as 2nd argument. (name) => is that function while "name" itself is just a variable name - like x, y or _. 

3. List.Transform passes column_list items, one by one.

4. Look at the context: we use this function as an argument of Table.TransformRows which in turn passes records (rows of the table) one by one to transformation function. So that x is record. 

Hello AlienSx,

always concerning your second solution, I tested it and I was wondering if it could be possible to make a change as in this way:

(data, replacements, condition_column as list, condition_value as list, columns_list as list) =>
[
// generates a record with replacements
repl = Function.Invoke(Record.FromList, List.Reverse(Table.ToColumns(replacements))),
transformations = List.Transform(columns_list, (name) => {name, (x) => Record.FieldOrDefault(repl, x, x)}),
// replace values in rows
replace = Table.TransformRows(
data, (x) => if Record.Field(x, condition_column) = condition_value
then Record.TransformFields(x, transformations)
else x
),
result = Table.FromRecords(replace)
][result]

The reason is because I am trying to check the conditions in two columns, instead of one.

I implemented that, and I invoked it in this way:

RULE_4 = replace_value_2(
#"Removed Columns1",
ReplacementTable_Body_StuffingBox,
{"Product_Series_Description","DN_Size"},
{"3 way", "DN10"},
{"Body_Material", "Stuffing_Box_Material"})

However the following error returned:

Could you suggest a solution?

Thanks.

I solved in this way:

(data, replacements, condition_column1, condition_column2, condition_value1,condition_value2, columns_list as list) =>
[
// generates a record with replacements
repl = Function.Invoke(Record.FromList, List.Reverse(Table.ToColumns(replacements))),
transformations = List.Transform(columns_list, (name) => {name, (x) => Record.FieldOrDefault(repl, x, x)}),
// replace values in rows
replace = Table.TransformRows(
data,
(x) => if Record.Field(x, condition_column1) = condition_value1 or

Record.Field(x, condition_column2) = condition_value2
then Record.TransformFields(x, transformations)
else x
),
result = Table.FromRecords(replace)
][result]

and IT WORKS!

However I have an issue with the original posted solution. In the condition value, I need to add a list of values to check in the column condition_column. I tried to do in this way:

RULE_2 = replace_value_UniqueCondition(
RULE_1,
ReplacementTable_Body_StuffingBox,
"Port_Type_1_2",
{"Butt Welding ASME BPE","Butt Welding DIN 11850 s2", "Butt Welding ISO 1127", "Butt Welding SMS 3008", "Clamp ASME BPE", "Clamp DIN 11850 s2", "Clamp ISO 1127", "Clamp SMS 3017", "Flange ANSI Standard 150", "Flange DIN EN 1092-1"},
{"Body_Material", "Stuffing_Box_Material"}),

and this is not working, it does not give any syntax error, but the function does not do what I would like.

Any inputs?

Thanks.