I am trying to wrap column values in brackets, so that e.g. foo becomes [foo]. I tried:
UPDATE notes
SET topics = regexp_replace(topics, '(.)', '[$1]')
However that does not error but also does not change the column values.
Any ideas how to do it?
We don't need a regex to put a string in brackets.
In most DBMS (MYSQL, Postgres, SQLServer, Maria DB) this can be done with CONCAT:
UPDATE notes
SET topics = CONCAT('[', topics, ']');
In a Oracle DB or SQLite, using || will do the same:
UPDATE notes
SET topics = '[' || topics || ']';
Related
I need a prepare an SQL script to be given to my production support team to run this in production. We have created a new column in the DB2 table. This column should be filled with the data by concatenating 3 column values of the same table in the same row.
To give a history, all the reason text which are entered in the front end are inserted into the request table by unstringing into 3 columns. Since they had limited length, we created a new column with increased length and going forward all insert will go into the new column. But we need to move all the existing data in the old 3 columns to his new one. S this SQL update is just an one time exercise.
Table: tab_request
We added new column to have a increased character length and to align with other table nomenclature. Now I need the script to update the column reasontext as below
update set field1 || .... should be your dml script. use coalesce() function to convert those null values to ''.
Update table1
set reasontext =
(coalesce(reason_1, '') || ' ' || coalesce(reason_2,'') || ' ' || coalesce(reason_3,''))
update tab_request set reasontext=CONCAT(reason_1,' ',reason_2,' ',reason_3)
If you want to avoid unnecessary spaces -- in the event that some reasons are NULL -- then you can use trim() with coalesce():
update table1
set reasontext = trim(coalesce(' ' || reason_1, '') ||
coalesce(' ' || reason_2, '') ||
coalesce(' ' || reason_3, '')
);
This is equivalent to concat_ws() available in some databases.
I am wish to update my database data in SQL Developer using
UPDATE TABLE_NAME SET COLUMN_NAME = LTRIM(RTRIM(COLUMN_NAME))
But it does not take any effect even the msg of "rows updated" is displayed. The leading and trailing white spaces still exist behind every strings.
Any ideas?
Do you commit after update?
update tableName set col1 = trim(col1);
commit;
I had the same problem on two different tables. One the first table trim was ok, on the second no effect, the spaces were still there!
The difference was that in the first table I was using varchar2(30) and in the second table (where trim didn't work) I had char(30)
After modifying the second table from char(30) to varchar2(30) trim worked as expected.
Try this
UPDATE TABLE_NAME SET COLUMN_NAME = TRIM(COLUMN_NAME);
Trim Reference
Have you tried REGEXP_REPLACE(your column name, '\s*', '') ?
ex: UPDATE TABLE_NAME SET COLUMN_NAME = REGEXP_REPLACE(COLUMN_NAME, '\s*', '')
You get a message saying that n rows are updated because there are n rows in your table and you are applying the update to all of them.
To limit the update to only those rows where the update will have an effect, use:
UPDATE TABLE_NAME
SET COLUMN_NAME = LTRIM(RTRIM(COLUMN_NAME))
WHERE COLUMN_NAME != LTRIM(RTRIM(COLUMN_NAME));
Im trying to update a field by appending data to it.
if it contains the data already i wont update it otherwise I will.
if it already contains data i want it to append a comma and space followed by the word. e.g.
update myTable
set Prefixes = convert(nvarchar(max),Prefixes) + ', abc'
where MyCol='xyz' and Prefixes not like '%abc%'
im trying to get this to work so that if the prefixes column is empty initially it only includes the word 'abc'
and not ', abc'
How can i do this?
Sounds like you need a CASE:
update myTable
set Prefixes =
case
when Prefixes is null or Prefixes = ''
then 'abc'
else convert(nvarchar(max),Prefixes) + ', abc'
end
where MyCol='xyz' and (Prefixes not like '%abc%' or Prefixes is null)
See SQL Fiddle with Demo
You need to check for null values of Prefixes before filtering as NOT LIKE in the WHERE clause as well. Sql-Demo
update myTable
set Prefixes = isnull(nullif(rtrim(Prefixes),'') + ', abc','abc')
where MyCol='xyz' and isnull(Prefixes,'') not like ', abc%'
I come from MySQL and the below query doesn't work in Sybase. How should I escape single quotes?
UPDATE Animals SET NAME = 'Dog\'s friends' WHERE uid = 12
If working with Sybase, having got used to MySQL which more database users have experience you may soon discover you are unable to escape single quotes with backslash in.
So how do you escape quotes in Sybase? In fact, in Sybase SQL the single quote acts as the escape character.
See below for an example UPDATE statement in both “languages”:
MySQL
UPDATE Animals SET NAME = 'Dog\'s friends' WHERE uid = 12
Sybase
UPDATE Animals SET NAME = 'Dog''s friends' WHERE uid = 12
I’m not entirely sure this makes sense to me (especially as it looks like a double quote) but there you go!
You can create a custom function to escape quotes :
CREATE FUNCTION "ESCAPE_QUOTES"(in a_string long varchar)
returns long varchar
begin
return replace(a_string, '''', '''''');
end
I searched around quite a bit, it would be great if someone could link me to a solution or answer my query.
The thing is I have a postgresql table that contains a lot of single quotes and I cant figure out how to get rid of them, because obviously this
update tablename set fieldname= NULL where fieldname=' ;
wont work.
Better use replace() for this:
UPDATE tbl SET col = replace(col, '''', '');
Much faster than regexp_replace() and it replaces "globally" - all occurrences of the search string. The previously accepted answer by #beny23 was wrong in this respect. It replaced first occurrences only, would have to be:
UPDATE tbl SET col = regexp_replace(col, '''', '', 'g');
Note the additional parameter 'g' for "globally". Read about string functions in the manual.
Aside: the canonical (and SQL standard) way to escape single quotes (') in string literals is to double them (''). Using Posix style escape sequences works, too, of course. Details:
Insert text with single quotes in PostgreSQL
update tablename set fieldname= NULL where fieldname='''' ;
or
update tablename set fieldname= NULL where fieldname=E'\'' ;
insert into table1(data) values ($$it's a string, it's got some single quotes$$)
Use $$ before and after the string. It will insert data.