I'm encountering weird behaviour of PostgreSQL where I try to run the following query
update posts
set content = replace(content, '\n', '<br>')
where content is not null;
and it's not doing anything to the data in the database. I **tried committing manually (including trying to run this query from psql) ** as well as setting DBeaver/pgAdmin to AUTOCOMMIT but to no avail.
The result tells me 37 rows have been updated, but the changes are not there. If I try to commit it tells me 0 rows affected.
I have no triggers at all, so that's out of the question.
Am I missing something here?
Use e before the literal:
update posts
set content = replace(content, e'\n', '<br>')
where content is not null
-- or better
-- where content like e'%\n%'
From the documentation (String Constants with C-Style Escapes):
An escape string constant is specified by writing the letter E (upper or lower case) just before the opening single quote.
Related
Lets say I have a database with about 50k entries in a column called content.
This column contains strings which causes problems to my further work.
Now here is the thing I need to do it for all the rows inside of that table.
Any Ideas?
Here an example:
'user wrote:
-----------------------------------------------------
> Some text
> that vary too much and I dont need it actually
> here is end of the text
The text I actually need.'
I would like to remove all of the unnecessary part so the only thing that is left is in this case :
'The text I actually need.'
This should delete all lines that start with a >:
regexp_replace(textcol, E'^>.*\n', '', 'gn');
The g flag is needed to delete all such lines, and the n flag makes the ^ match the position right after each line break.
I use an “extended” string literal (the leading E) so that I can write a newline as \n.
I have a strange situation displaying value from SQL server. There is a value stored in SQL server 2008 field which is hidden when queried from server and shown in Management Studio (see below).
Test template 2
But when displayed on a screen in HTML editor it is showing as ? (see below)
Test template 2?
When I check for ascii value it shows 63. Not sure how user got this special value into this field in SQL server. When I test by entering ? into input field and display it works fine without any issues.
I don't want to blindly remove last character from this field. I am trying to determine a solution to identify this invisible value and remove it either while storing or displaying.
Any solution is greatly appreciated.
As comments below suggests this turned out to be Unicode 8203 (zero width space).
My next question is how to replace this Unicode 8203 in one statement in T-SQL without parsing through each character?
Use REPLACE to remove the zero-width space character:
-- setup unicode string containing zero-width character
DECLARE #UnicodeReplace NVARCHAR(5) = N'Test' + NCHAR(8203);
-- check that unicode string length is 5,
-- and prove existence of zero-width space character matching unicode 8203
SELECT #UnicodeReplace AS String,
LEN(#UnicodeReplace) AS Length,
UNICODE(SUBSTRING(#UnicodeReplace, 5, 1)) AS UnicodeValue
-- replace and prove the unicode string length is reduced to 4
SELECT REPLACE(#UnicodeReplace, NCHAR(8203), N''),
LEN(REPLACE(#UnicodeReplace, NCHAR(8203), N'')) AS Length;
SQL Fiddle
Such characters could not be replaced if database collation has default values like this: SQL_Latin1_General_CP1_CI_AS. In such cases this command could work:
set #word=replace(#word collate Latin1_General_100_BIN2, nchar(8205),N'')
I'm trying to use the REPLACE function in SQL and I am having problems with trying to append a string to the end of the current contents of a column.
set ActualRegex = REPLACE(ActualRegex, ActualRegex, ActualRegex + '[\d\D]*')
These strings will be used for Regex checks in a C# program, but that's not particularly relevant to the problem.
When I try running this query, i end up getting an error message
Msg 8152, Level 16, State 14, Line 1
String or binary data would be truncated.
The statement has been terminated.
I've checked the field sizes, and the resulting strings will not be nearly long enough to exceed the size of the field (varchar(512)). At biggest they might be 50 characters long unless something strange is happening that I'm unaware about.
Thanks in advance for any help!
EDIT: Here's the full query
update [Registration].[dbo].[MigrationOfTagTypes] set ActualRegex =
REPLACE(ActualRegex, ActualRegex, ActualRegex + '[\d\D]*')
where Regex != '' and Regex like '%\%' escape '\'
EDIT: Actually, I figured it out and turns out I was just being stupid and overlooking something small. Apparently these fields were filled with lots of empty whitespace appended onto the end of the strings, so appending to that would result in breaking the size constraint. Thanks for all the help!
Msg 8152, Level 16, State 14, Line 1
String or binary data would be truncated.
The statement has been terminated.
There are two reasons for this:
Your varchar column is not large enough. Appending 7 characters to an existing 10 into a varchar(15) column won't work
Your column is defined as char (why?!). Char columns have implicit trailing spaces, so if you add 'ABC' to a char(10) field containing 'XYZ', it actually ends up as 'XYZ ABC' (13) which is longer than char(10).
In the 2nd case, i.e. char columns, use RTRIM
update [Registration].[dbo].[MigrationOfTagTypes] set ActualRegex =
RTRIM(REPLACE(ActualRegex, ActualRegex, ActualRegex + '[\d\D]*'))
where Regex != '' and Regex like '%\%' escape '\'
Note: using replace like this allows 'ABCxxxABC' to become 'ABC[\d\D]*xxxABC[\d\D]*'
If you simply wanted to append to the end of the column, then you would use
update [Registration].[dbo].[MigrationOfTagTypes]
set ActualRegex = RTRIM(ActualRegex) + '[\d\D]*'
where Regex != '' and Regex like '%\%' escape '\'
Is it possible that concat is more useful?
As far as the error message goes, I do not know why it is generated, but than again, it has been a while since I used MS SQL for the last time.
I'm thinking it's possible that your column is being aggregated recursively, ad infinitum. Or at least ad 512 characters.
If this is the case, you'll have to offload the current table contents into a temporary table, then use that data to perform the update back onto the original table.
I'm researching if this is possible right now.
This question already has answers here:
SQL query for a carriage return in a string and ultimately removing carriage return
(10 answers)
Closed 8 years ago.
Facing a problem, it seems my data stored in SQL Server does not stored correctly, simply put, how to verify that a varchar data has carriage return and line feed in it? I try to print them out, does not show the special characters.
Thanks
You can use SQL Server's char(n) and contains() functions to match on field contents in your WHERE clause.
carriage return: char(13)
line feed: char(10)
The following SQL will find all rows in some_table where the values of some_field contain newline and/or carriage return characters:
SELECT * FROM some_table
WHERE CONTAINS(some_field, char(13)) OR CONTAINS(some_field, char(10))
To remove carriage returns in your some_field values you could use the replace() function long with char() and contains(). The SQL would look something like:
UPDATE some_table
SET some_field = REPLACE(some_field, char(13), '')
WHERE CONTAINS(some_field, char(13))
To remove new lines you can follow up the last statement with the char(10) version of that update. How you do it all depends on what types of newlines your text contains. But, depending on where the text was inserted/pasted from the new lines may be \r\n or \n so running updates against both \r and \n characters would be safer than assuming that you're getting one version of newline or the other.
Note that if the newlines were removed and you want to retain them then you have to fix the issue at the point of entry. You can't replace or fix what has been removed so you should save the original text data in a new column that holds the original, unmodified text.
To add to what others have said; when I need to embed newlines in T-SQL, I tend to do;
DECLARE #nl CHAR(2) = CHAR(13) + CHAR(10);
..then use #nl as required. That's for Windows line-endings, naturally.
Take a look at the Char function. See MSDN. This will help look for the special characters.
I'm using SQL Plus 11.1.0.6.0 to run a script that performs batch inserts into an Oracle 10g db.
The problem i noticed is when inserting some code string into a clob field that has some lines with trailing spaces such as:
....public void myMethod().... --trailing space here
....{
........int myVar = 1;
........ -- empty line with trailing spaces
........myVar+=1
....}
The string that gets inserted in the table looses those empty trailing spaces in the empty lines and becomes:
....public void myMethod() --trailing space is lost
....{
........int myVar = 1;
-- empty line without trailing spaces
........myVar+=1
....}
Although it makes no difference to the useful data, this is quite frustrating because it's causing the data to differ from the original and fails some tests.
All i could find was SET TRIMSPOOL/TRIMOUT OFF which doesn't change anything, does anyone have some other ideas?
Without posting your script it's hard to be sure, but you probably shouldn't be inserting text strings directly into a CLOB in SQLPlus. If you were to use a PL/SQL proc that pulled in your text from a file and call the PL/SQL from SQLPlus it should keep all the formatting.
But that may be an almighty PITA. But it's well documented in the O'Reilly PL/SQL texts.
In the end i solved it by a hack like this (considering original example):
declare
myLargeValue_2 clob;
begin
myLargeValue_2 := '....public void myMethod()'||'....
'||'....{
........int myVar = 1;
'||'........' -- empty line with trailing spaces
and so on
Basically concatenated explicitly all the whitespaces
You can try to enable following parameter:
SET SQLBLANKLINES ON