I have a table column containing values which I would like to remove all the hyphens from. The values may contain more than one hyphen and vary in length.
Example: for all values I would like to replace 123 - ABCD - efghi with 123ABCDefghi.
What is the easiest way to remove all hyphens & update all column values in the table?
You can use the regexp_replace function to left only the digits and letters, like this:
update mytable
set myfield = regexp_replace(myfield, '[^\w]+','');
Which means that everything that is not a digit or a letter or an underline will be replaced by nothing (that includes -, space, dot, comma, etc).
If you want to also include the _ to be replaced (\w will leave it) you can change the regex to [^\w]+|_.
Or if you want to be strict with the characters that must be removed you use: [- ]+ in this case here a dash and a space.
Also as suggested by Luiz Signorelly you can use to replace all occurrences:
update mytable
set myfield = regexp_replace(myfield, '[^\w]+','','g');
You can use this.
update table
set column = format('%s%s', left(column, 3), right(column, -6));
Before:
After:
Related
I am trying to remove using REGEXP_REPLACE the following special characters: "[]{}
from the following text field: [{"x":"y","s":"G_1","cn":"C8"},{"cn":"M2","gn":"G_2","cn":"CA99"},{"c":"ME3","gn":"G_3","c":"CA00"}]
and replace them with nothing, not even a space.
*Needless to say, this is just an example string, and I need to find a consistent solution for similar but different strings.
I was trying to run the following: SELECT REGEXP_REPLACE('[{"x":"y","s":"G_1","cn":"C8"},{"cn":"M2","gn":"G_2","cn":"CA99"},{"c":"ME3","gn":"G_3","c":"CA00"}] ','[{[}]":]','')
But received pretty much the same string..
Thanks in advance!
You need to escape the special characters (\), and to specify that you want to repeat the operation for every characters ('g') else it will stop at the 1st match
SELECT REGEXP_REPLACE(
'[{"x":"y","s":"G_1","cn":"C8"},{"cn":"M2","gn":"G_2","cn":"CA99"},{"c":"ME3","gn":"G_3","c":"CA00"}] ',
'[{\[}\]":]',
'',
'g');
regexp_replace
--------------------------------------------------
xy,sG_1,cnC8,cnM2,gnG_2,cnCA99,cME3,gnG_3,cCA00
(1 row)
In Redshift we are trying to give more meaningful aliases to the columns we are returning from the queries as we are importing the results into TABLEAU, the issue is that RedShift turns all the letter to lower case ones, i.e. from "Event Date" it then returns "event date", any idea on how to work this one out to keep the alias given?
I know I'm a bit late to the party but for anyone else looking, you can enable case sensitivity, so if you want to return a column with camel casing for example
SET enable_case_sensitive_identifier TO true;
Then in your query wrap what you want to return the column as in double quotes
SELECT column AS "thisName"
Or as per OP's example
SELECT a.event_date AS "Event Date"
https://docs.aws.amazon.com/redshift/latest/dg/r_enable_case_sensitive_identifier.html
Edit: To have this behaviour as default for the cluster you will need to create/update a parameter group in Configurations => Workload Management. You can't change the settings for the default parameter group. Note, you will need to reboot the cluster after applying the parameter group for the changes to take effect.
No, you cannot do this in Redshift. all columns are lowercase only.
You can enforce upper case only by using
set describe_field_name_in_uppercase to on;
Also see the examples here https://docs.aws.amazon.com/redshift/latest/dg/r_names.html you can see that the upper case characters are returned as lower case. and it says "identifiers are case-insensitive and are folded to lowercase in the database"
You can of course rename the column to include uppercase within Tableau.
I was going through AWS docs for redshift and looks like INTCAP function can solve your use case
For reference => https://docs.aws.amazon.com/redshift/latest/dg/r_INITCAP.html
Brief description (copied)
The INITCAP function makes the first letter of each word in a string uppercase, and any subsequent letters are made (or left) lowercase. Therefore, it is important to understand which characters (other than space characters) function as word separators. A word separator character is any non-alphanumeric character, including punctuation marks, symbols, and control characters. All of the following characters are word separators:
! " # $ % & ' ( ) * + , - . / : ; < = > ? # [ \ ] ^ _ ` { | } ~
And in your case you have declared field name as event_date which will convert to Event_Date.
And next you can use REPLACE function to replace underscore '_'
For reference => https://docs.aws.amazon.com/redshift/latest/dg/r_REPLACE.html
You need to put
set describe_field_name_in_uppercase to on;
in your Tableau's Initial SQL.
I need to find the values from a text column which have characters other than alphabets, numbers, and SPACE (It is a name column so having space is allowed).
I am trying this which is not working
select * from table where name ~ '[^a-z0-9 ]';
I have left a space between 9 and ]
The correct regular expression would be:
[^[:alnum:] ]
That will match any string that contains a character that is neither alphabetical nor numerical nor space.
Try ^[-a-z0-9 ]
I think you can use \\w instead of a-z0-9
so that looks like : [-\\w.]
I need to remove leading zeros and hyphens from a column value in Postgresql database, for example:
121-323-025-000 should look like 12132325
060579-0001 => 605791
482-322-004 => 4823224
timely help will be really appreciated.
Postgresql string functions.
For more advanced string editing, regular expressions can be very powerful. Be aware that complex regular expressions may not be considered maintainable by people not familiar with them.
CREATE TABLE testdata (id text, expected text);
INSERT INTO testdata (id, expected) VALUES
('121-323-025-000', '12132325'),
('060579-0001', '605791'),
('482-322-004', '4823224');
SELECT id, expected, regexp_replace(id, '(^|-)0*', '', 'g') AS computed
FROM testdata;
How regexp_replace works. In this case we look for the beginning of the string or a hyphen for a place to start matching. We include any zeros that follow that as part of the match. Next we replace that match with an empty string. Finally, the global flag tells us to repeat the search until we reach the end of the string.
I want to list the trigger no system ending with "_BI" in firebird database,
but no result with this
select * from rdb$triggers
where
rdb$trigger_source is not null
and (coalesce(rdb$system_flag,0) = 0)
and (rdb$trigger_source not starting with 'CHECK' )
and (rdb$trigger_name like '%BI')
but with this syntaxs it gives me a "_bi" and "_BI0U" and "_BI0U" ending result
and (rdb$trigger_name like '%BI%')
but with this syntaxs it gives me null result
and (rdb$trigger_name like '%#_BI')
thank you beforehand
The problem is that the Firebird system tables use CHAR(31) for object names, this means that they are padded with spaces up to the declared length. As a result, use of like '%BI') will not yield results, unless BI are the 30th and 31st character.
There are several solutions
For example you can trim the name before checking
trim(rdb$trigger_name) like '%BI'
or you can require that the name is followed by at least one space
rdb$trigger_name || ' ' like '%BI %'
On a related note, if you want to check if your trigger name ends in _BI, then you should also include the underscore in your condition. And as an underscore in like is a single character matcher, you need to escape it:
trim(rdb$trigger_name) like '%\_BI' escape '\'
Alternatively you could also try to use a regular expressions, as you won't need to trim or otherwise mangle the lefthand side of the expression:
rdb$trigger_name similar to '%\_BI[[:SPACE:]]*' escape '\'