I am trying to use RIGHT function in SQL Server Management Studio 17. But I continue getting a blank result. I used TRIM function to update my data, and then used LEN function to test the length, there is no extra space in this column.
But when I used TRIM function inside RIGHT, I can get the result I want.
So what is the problem here and how can I solve it?
Thank you!
SELECT RIGHT(FIRST_NAME,3) FROM Worker;
SELECT LEN(FIRST_NAME) FROM Worker;
SELECT RIGHT(TRIM(FIRST_NAME),3) FROM Worker;
The problem is probably that you have use char() instead of varchar() for the first_name. This automatically pads the name with spaces.
In general, you want to store strings as varchar(). There are some circumstances where char() is useful -- such as for country codes which are uniformly 2- or 3- characters. But in general, you want varchar().
This is a known feature of using LEN. Simply switch to DATALENGTH instead and you'll get the correct length for each column:
SELECT DATALENGTH(FIRST_NAME) FROM Worker;
For LEN, taken here directly from the article:
Returns the number of characters of the specified string expression,
excluding trailing blanks.
And DATALENGTH in turn:
Returns the number of bytes used to represent any expression.
If you would like to remove the trailing spaces from your existing rows, run a simple UPDATE query:
UPDATE Worker SET FIRST_NAME = TRIM(FIRST_NAME);
Related
I have a column of strings that have an '&' at the beginning and end of each one that I need to remove for a Crystal report I'm creating. I'm writing the SQL code outside of Crystal I am using Intersystems Cache SQL. Below is an example:
&This& This
&is& is
&What& what
&it& I
&looks& need
&like& it
&now& to
look
like
Any suggestions would be greatly appreciated!!!
Assuming the ampersands are always positioned as both the leading and trailing characters, here's at least maybe a start. Use a combination of SUBSTR (or SUBSTRING, if using stream data) and LENGTH, like so:
SELECT SUBSTR((SELECT column FROM table), 2, LENGTH(SELECT column FROM table) - 2)
This should return a substring that starts counting at the 2nd character [of the original string, given by the first sub-expression/argument to SUBSTR], counting up for the total number of characters [of the original string] less 2 (i.e. less the two ampersands).
If you need to including trailing blanks and/or the string termination character, you may need to use a different variation of the LENGTH function. See resources for details on these functions and their variants:
https://docs.intersystems.com/irislatest/csp/docbook/DocBook.UI.Page.cls?KEY=RSQL_substr
https://cedocs.intersystems.com/latest/csp/docbook/DocBook.UI.Page.cls?KEY=RSQL_length
Here's a Crystal formula that does the same:
ExtractString({YourData},"&","&")
I am running below query in Teradata :
sel requesttext from dbc.tables
where tablename='old_employee_table'
Result:
alter table DB_NAME.employee_table,no fallback ;
I want to get below result using SQL:
DB_NAME.employee_table
Requesttext can be:
create set table DB_NAME.employee_table;
DB Name and table can occur anywhere in the result. Since .(dot) is joining them that's why i want to split with .(dot).
Basically I need sql which can result me surrounding values of .(dot)
I want DBName and Tablename in result.
I'm not a Teradata person, but this should work for both strings given so far, as long as teradata's regexp_substr() supports positive look-behind and positive look-ahead assertions (I might have the Teradata syntax wrong, so a little tweaking may be needed):
SELECT REGEXP_SUBSTR(requesttext, '(?<= )(\w+\.\w+)(?=[,$]?)', 1, 1)
FROM dbc.tables
WHERE tablename='old_employee_table'
See the regex101 example. Hopefully it translates to Teradata easily.
The regex looks for and returns the words either side of and including the period, when preceded by a space, and followed by an optional comma or the end of the line.
You could do this with either regexp_substr() or strtok().
As Jamie Zawinski said:
Some people, when confronted with a problem, think "I know, I'll use
regular expressions." Now they have two problems.
So I would go with the strtok() method. Also I'm lazy and regular expressions are hard.
Function strtok() takes three arguments:
The string being split
The delimiter to split the string
The number of the token to grab.
To get at the <database>.<table> from that string that is returned in your query, we can split by a space, grab the third token, then split that by a comma and grab the first token.
That would look like:
SELECT strtok(strtok(requestText,' ',3),',',1)
FROM dbc.tables
WHERE tablename='old_employee_table'
So i have a file I'm creating using SQL Server 2012.
Many of the columns are optional or unused, and in place of the characters that would normally be there we are asked to zero-fill numeric columns, and space-fill alphanumeric columns.
Now I have a column called CDD and it's 256 characters long.
Is there a simpler way I can fill this column other than pressing the space bar 256 times in single quotes?
The file is Fixed Width so I have to have 256 spaces in this column for it to import correctly. I was looking at replicate and stuff, but they don't make sense being that the column doesn't have an original string to replace.
Replicate works with zeros but how can I validate it with spaces? The column doesn't expand like it would if there was an actual character in it...Does SQL-Server do any collapsing of white space in this way?
You're going to want to use the replicate function.
SELECT REPLICATE(' ',256)
This function will repeat space (or whatever string you put in the first parameter) 256 (or however many in the second parameter) times.
In addition to REPLICATE you can also use
SELECT SPACE(256);
As far as "the column expanding", the column will not appear expanded in SSMS unless you click on 'Results in Text' (instead of grid). If you use the LEN function it will return 0, but DATALENGTH will return either the actual number of spaces requested for a varchar column, or the defined length of a char column. Either way, if you copy the output into a text editor, you will see that it is indeed a string of empty spaces.
I have a query that is returning data from a database. In a single field there is a rather long text comment with a segment, which is clearly defined with marking tags like !markerstart! and !markerend!. I would like to have a query return with the string segment between the two markers removed (and the markers removed too).
I would normally do this client-side after I get the data back, however, the problem is that the query is an INSERT query that gets it's data from a SELECT statement. I don't want the text segment to be stored in the archival/reporting table (working with an OLTP application here), so I need to find a way to get the SELECT statement to return exactly what is to be inserted, which, in this case, means getting the SELECT statement to strip out the unwanted phrase instead of doing it in post-processing client-side.
My only thought is to use some convoluted combination of SUBSTRING, CHARINDEX, and CONCAT, but I'm hoping there is a better way, but, based on this, I don't see how. Anyone have ideas?
Sample:
This is a long string of text in some field in a database that has a segment that needs to be removed. !markerstart! This is the segment that is to be removed. It's length is unknown and variable. !markerend! The part of this field that appears after the marker should remain.
Result:
This is a long string of text in some field in a database that has a segment that needs to be removed. The part of this field that appears after the marker should remain.
SOLUTION USING STUFF:
I really don't like how verbose this is, but I can put it in a function if I really need to. It isn't ideal, but it is easier and faster than a CLR routine.
SELECT STUFF(CAST(Description AS varchar(MAX)), CHARINDEX('!markerstart!', Description), CHARINDEX('!markerend!', Description) + 11 - CHARINDEX('!markerstart!', Description), '') AS Description
FROM MyTable
You may want to consider implementing a CLR user-defined function that returns the parsed data.
The following link demonstrates how to use a CLR UDF RegEx function for pattern matching and data extraction.
http://msdn.microsoft.com/en-us/magazine/cc163473.aspx
Regards,
You can use Stuff function or Replace function and replace your unwanted symbols with ''.
STUFF('EXP',START_POS,'NUMBER_OF_CHARS','REPLACE_EXP')
Does anyone know a good way to count characters in a text (nvarchar) column in Sql Server?
The values there can be text, symbols and/or numbers.
So far I used sum(datalength(column))/2 but this only works for text. (it's a method based on datalength and this can vary from a type to another).
You can find the number of characters using system function LEN.
i.e.
SELECT LEN(Column) FROM TABLE
Use
SELECT length(yourfield) FROM table;
Use the LEN function:
Returns the number of characters of the specified string expression, excluding trailing blanks.
Doesn't SELECT LEN(column_name) work?
text doesn't work with len function.
ntext, text, and image data types will be removed in a future version
of Microsoft SQL Server. Avoid using these data types in new
development work, and plan to modify applications that currently use
them. Use nvarchar(max), varchar(max), and varbinary(max) instead. For
more information, see Using Large-Value Data Types.
Source
I had a similar problem recently, and here's what I did:
SELECT
columnname as 'Original_Value',
LEN(LTRIM(columnname)) as 'Orig_Val_Char_Count',
N'['+columnname+']' as 'UnicodeStr_Value',
LEN(N'['+columnname+']')-2 as 'True_Char_Count'
FROM mytable
The first two columns look at the original value and count the characters (minus leading/trailing spaces).
I needed to compare that with the true count of characters, which is why I used the second LEN function. It sets the column value to a string, forces that string to Unicode, and then counts the characters.
By using the brackets, you ensure that any leading or trailing spaces are also counted as characters; of course, you don't want to count the brackets themselves, so you subtract 2 at the end.