How to Replace Multiple Characters in Access SQL?

I'm a novice at SQL, so hopefully someone can spell this out for me. I tried following the "Replace Multiple Strings in SQL Query" posting, but I got stuck.

I'm trying to do the same thing as the originator of the above posting but with a different table and different fields. Let's say that the following field "ShiptoPlant" in table "BTST" has three records (my table actually has thousands of records)...

Table Name: BTST

   ---------------
   | ShiptoPlant |
   | ----------- |
   | Plant #1    |
   | Plant - 2   |
   | Plant/3     |
   ---------------

Here's what I'm trying to type in the SQL screen:

SELECT CASE WHEN ShipToPlant IN ("#", "-", "/") Then ""
ELSE ShipToPlant END FROM BTST;

I keep getting the message (Error 3075)...

"Syntax error (missing operator) in query expression 'CASE WHEN ShiptoPlant IN (";","/"," ") Then "" ELSE ShipToPlant END'."

I want to do this operation for every character on the keyboard, with exception of "*" since it is a wildcard.

Any help you could provide would be greatly appreciated!

EDIT: Background Information added from the comments

I have collected line-item invoice-level data from each our 14 suppliers for the 2008 calendar year. I am trying to normalize the plant names that are given to us by our suppliers.

Each supplier can call a plant by a different name e.g.

Signode Service on our master list could be called by suppliers

Signode Service 
Signode - Service.
SignodeSvc
SignodeService

I'm trying to strip non-alphanumeric chars so that I can try to identify the plant using our master listing by creating a series of links that look at the first 10 char, if no match, 8 char, 6, 4...

My basic hang-up is that I don't know how to strip the alphanumeric characters from the table. I'll be doing this operation on several columns, but I planned on creating separate queries to edit the other columns.

Perhaps I need to do a mass update query that strips all the alphanumerics. I'm still unclear on how to write it. Here's what I started out with to take out all the spaces. It worked great, but failed when I tried to nest the replace

UPDATE BTST SET ShipToPlant = replace(ShipToPlant," ","");

EDIT 2: Further Information taken from Comments

Every month, up to 100 new permutations of our plant names appear in our line item invoice data- this could represent thousands of invoice records. I'm trying to construct a quick and dirty way to assign a master_id of the definitive name to each plant name permutation. The best way I can see to do so is to look at the plant, address, city and state fields, but the problem with this is that these fields have various permutations as well, for example,

128 Brookview Drive
128 Brookview Lane

By taking out alphanumerics and doing

LEFT(PlantName,#chars) &LEFT(Address,#chars)&LEFT(City,#chars)&LEFT(State,#chars)

and by changing the number of characters until a match is found between the invoice data and the Master Plant Listing (both tables contain the Plant, Address, City and State fields), you can eventually find a match. Of course, when you start dwindling down the number of characters you are LEFTing, the accuracy becomes compromised. I've done this in excel and had decent yield. Can anyone recommend a better solution?

From stackoverflow

• Don't think Access supports the CASE statement. Consider using iif:

  iif ( condition, value_if_true, value_if_false )
  

  For this case you can use the REPLACE function:

  SELECT 
      REPLACE(REPLACE(REPLACE(yourfield, '#', ''), '-', ''), '/', '') 
      as FieldName
  FROM
      ....
  

  David-W-Fenton : IIf() will be much worse. If you have 35 values you want to replace, then you need to write a function to do this.

• 
  SELECT 
  IIF
  (
      Instr(1,ShipToPlant , "#") > 0 
      OR Instr(1,ShipToPlant , "/") > 0 
      OR Instr(1,ShipToPlant , "-") > 0, ""
      , ShipToPlant 
  )
  FROM BTST
  
  

• OK, your question has changed, so the solution will too. Here are two ways to do it. The quick and dirty way will only partially solve your issue because it won't be able to account for the more odd permutations like missing spaces or misspelled words. The quick and dirty way:

  1. Create a new table - let's call it tChar.
  2. Put a text field in it - the char(s) you want to replace - we'll call it char for this example
  3. Put all the char or char combinatios that you want removed in this table.

  4. Create and run the query below. Note that it will only remove one item at a time, but you can also put different versions of the same replacement in it too like ' -' or '-' For this example I created a table called tPlant with a field called ShipToPlant.

     SELECT tPlant.ShipToPlant, Replace([ShipToPlant], (SELECT top 1 char FROM tChar WHERE instr(ShipToPlant,char)<>0 ORDER BY len(char) Desc),"" ) AS New FROM tPlant;

  The better (but much more complex) way. This explanation is going to be general because it would be next to impossible to put the whole thing in here. If you want to contact me directly use my user name at gmail.:

  1. Create a table of Qualifiers - mistakes that people enter like svc instead of service. Here you would enter every wierd permutation you get.
  2. Create a table with QualifierID and Plant ID. Here you would say which qualifier goes to which plant.
  3. Create a query that joins the two and your table with mistaken plant names in it. Use instr so say what is in the fields.
  4. Create a second query that aggragates the first. Count the instr field and use it as a score. The entry with the highest score is the plant.
  5. You will have to hand enter the ones it can't find, but pretty soon that will be next to none as you have more and more entries in the table.

  ughh

  ---

  You have a couple different choices. In Access there is no CASE in sql, you need to use IIF. It's not quite as elegant as the solutions in the more robust db engines and needs to be nested for this instance, but it will get the job done for you.

  SELECT
      iif(instr(ShipToPlant,"#")<>0,"",
      iif(instr(ShipToPlant,"-")<>0,"",
      iif(instr(ShipToPlant,"/")<>0,"",ShipToPlant ))) AS FieldName
  FROM BTST;
  

  You could also do it using the sql to limit your data.

  SELECT YourID, nz(aBTST.ShipToPlant,"") AS ShipToPlant  
  FROM BTST LEFT JOIN (
      SELECT YourID, ShipToPlant 
      FROM BTST 
      WHERE ShipToPlant NOT IN("#", "-", "/")
      ) as aBTST ON BTST.YourID=aBTST.YourID
  

  If you know VB you can also create your own functions and put them in the queries...but that is another post. :) HTH

  Praesagus : Now that you have updated your question it is a much different scenario. You are on the right track - Replace is the answer. UPDATE BTST SET ShipToPlant = replace(replace(replace(ShipToPlant,"#",""),"-",""),"/",""). Or run 3 queries with one replace each.

• You could use the built in Replace function within Access

  SELECT
      Replace(Replace(Replace(ShipToPlant, "#", ""), "-", ""), "/", "") AS ShipToPlant
  FROM
      BTST
  

  As others have said, within Access you can write your own functions in VBA and use them in your queries.

  EDIT:

  Here's a way to handle the nested Replace limit by wrappering the Replace function within our own function. It feels dirty but it works- put this in a module within Access

  Public Function SuperReplace(ByRef field As String, ByVal ReplaceString As String) As String
      ' Size this as big as you need... it is zero-based by default' 
      Dim ReplaceArray(3) As String
  
      'Fill each element with the character you need to replace'  
      ReplaceArray(0) = "#"
      ReplaceArray(1) = "-"
      ReplaceArray(2) = "/"
      ReplaceArray(3) = " "
  
      Dim i As Integer
      For i = LBound(ReplaceArray) To UBound(ReplaceArray)    
         field = Replace(field, ReplaceArray(i), ReplaceString)
      Next i
  
      SuperReplace = field    
  End Function
  

  Then test it with this query

  SELECT 
      SuperReplace(ShipToPlant,"") AS ShipToPlant
  FROM
      BTST
  

  You might want to take this an expand it so that you can pass in an array of strings instead of hard-coding them into the function.

  EDIT 2:

  In response to the additional information in the comments on the question, here's a suggestion for how you might want to handle the situation differently. The advantage to this apprach is that once you have mapped in a plant name permutation, you won't need to perform a string replace on future data in future years, only add new plant names and permutations to the map.

  Start with creating another table, let's call it plant_map

  CREATE TABLE plant_map (id AUTOINCREMENT PRIMARY KEY, name TEXT, master_id LONG)
  

  into plant_map, add all of the permutations for plant names and insert the id for the name you wish to use to refer to a particular plant name permutation group with, into the master_id field. From your comments, I'll use Signode Service

  INSERT INTO plant_map(name, master_id) VALUES ("Signode Service", 1);
  INSERT INTO plant_map(name, master_id) VALUES ("Signode Svc", 1);
  INSERT INTO plant_map(name, master_id) VALUES ("Signode - Service", 1);
  INSERT INTO plant_map(name, master_id) VALUES ("Signode svc", 1);
  INSERT INTO plant_map(name, master_id) VALUES ("SignodeService", 1);
  

  Now when you query BTST table, you can get data for Signode Service using

  SELECT
      field1,
      field2
  FROM
      BTST source
  INNER JOIN
      (
      plant_map map1      
      INNER JOIN
      plant_map map2
      ON map1.master_id = map2.id
      )
      ON source.ShipToPlant = map1.name
  WHERE
      map2.name = "Signode Service"
  

  Data within table BTST can remain unchanged.

  Essentially, this is joining on the plant name in BTST to the name in plant_map then, using master_id, self joining on id within plant_map so that you need only pass in one "common" name. I would advise putting an index on each of the columns name and master_id in plant_map as both fields will be used in joins.

  Russ Cam : I don't envy having 100 new permutations of the plant names every month - can the process of customers detailing plant names be tightened up in any way, or is it entirely out of your control? It sounds like you might want to look at pattern matching to ascertain whether 2 plants are the same plant

  onedaywhen : +1 for the _map table approach. FWIW in our shop we identify such tables by appending the element name 'Synonyms'.

• Create a public function in a Code module.

  Public Function StripChars(ByVal pStringtoStrip As Variant, ByVal pCharsToKeep As String) As String
  
  Dim sChar As String
  Dim sTemp As String
  Dim iCtr As Integer
  
    sTemp = ""
  
    For iCtr = 1 To Len(pStringtoStrip)
      sChar = Mid(pStringtoStrip, iCtr, 1)
      If InStr(pCharsToKeep, sChar) > 0 Then
        sTemp = sTemp & sChar
      End If
    Next
  
    StripChars = sTemp
  
  End Function
  

  Then in your query

  SELECT
      StripChars(ShipToPlant, "abcdefghijklmnopqrstuvwxyz0123456789") AS ShipToPlantDisplay  
  FROM 
      BTST
  

  Notes - this will be slow for lots of records - if you what this to be permanent then create an update query using the same function.

  EDIT: to do an Update:

  UPDATE BTST
      SET ShipToPlant = StripChars(ShipToPlant, "abcdefghijklmnopqrstuvwxyz0123456789")
  

  DJ : Sorry - slight typo -> If InStr(sCharsToKeep, sChar) > 0 Then should be If InStr(pCharsToKeep, sChar) > 0 Then - I updated my answer - also you list the characters you want to keep - anything else will get stripped.

• You may wish to consider a User Defined Function (UDF)

  SELECT ShiptoPlant, CleanString([ShiptoPlant]) AS Clean
  FROM Table
  
  
  Function CleanString(strText)
  Dim objRegEx As Object
  
  Set objRegEx = CreateObject("VBScript.RegExp")
  objRegEx.IgnoreCase = True
  objRegEx.Global = True
  
  objRegEx.Pattern = "[^a-z0-9]"
  CleanString = objRegEx.Replace(strText, "")
  
  End Function
  

  HansUp : +1 I don't understand why this answer was not accepted. Clearly it would be easy to do "UPDATE BTST SET ShipToPlant = CleanString(ShipToPlant);"

• By the way, Russ, DJ or anyone else -- if you would like to see a snapshot of the two files I'm trying to work with, I can send them to your personal emails. I'd rather not post them here. If you want to coordinate a quick call, I could work that out as well. Let me know.

• All - I wound up nesting the REPLACE() function in two separate queries. Since there's upwards of 35 non-alphanumeric characters that I needed to replace and Access limits the complexity of the query to somewhere around 20 nested functions, I merely split it into two processes. Somewhat clunky, but it worked. Should have followed the KISS principle in this case. Thanks for your help!

  Praesagus : Did you see the query string example I made for you? It will essentially take the place of as many replaces as you want in your recordset, plus you can manage them all from a table. very easy. :)