Logical operation using length of text column in SQL database - sql

I have a column "names", which is defined as a text column. I want to select names which contain more than 10 characters. First thought was
WHERE len(names) > 10
"Len" doesn't work with text, though. I found out about DATALENGTH, but it doesnt't work either and I get a message that I should change column types.
Isn't there any way to do this while keeping this column as text?

I think that you should try using WHERE length(name) > 10

Seems like the built-in LENGTH function is all you need. It works for char, varchar, text, etc.
select names, length(names) from myTable
select names from myTable where length(names) > 10

Related

Removing characters after a specified character format

I have a field that should contain 6 digits, a period, and six digits (######.######). The application that I use allows this to be free-form entry. Because users are users and will do what they want I have several fields that have a dash and some letters afterwards (######.######-XYZ).
Using T-SQL how do I identify and subsequently remove the -XYZ so that I can return the integrity of the data. The column is an NVARCHAR(36), PK, and does not allow null values. The column in question does have a unique columnID field.
If the part you want is the first 13 characters, then use left():
select left(field, 13)
You can check if the first 13 characters are what you expect:
select (case when field like '[0-9][0-9][0-9][0-9][0-9][0-9].[0-9][0-9][0-9][0-9][0-9][0-9]%'
then left(field, 13)
else -- whatever you want when the field is bad
end)
since it'a free-form and "users are users", use charindex to find out if 1) there is a - and 2) remove it.
Example:
DECLARE #test NVARCHAR(36) = N'######.######-XYZ'
SELECT SUBSTRING(#test,1,COALESCE(NULLIF(CHARINDEX('-',#test,1),0),LEN(#test)+1)-1)

Using SQL to make specific changes in a database.

I am trying to figure out some commands/code in SQL.
I have database with names, addresses IDs etc, but I have to convert firstname values ending in “jnr” to “(Jnr)” and those ending in “snr” to “(Snr)”.
How do I do this?
update table TABLE_NAME set NAMES = '*xyz*Jnr' where NAMES like '%jnr'
Update or select:
PASTE(column, CHAR_LENGTH(column)-3, 1, UPPER(SUBSTRING(column FROM CHAR_LENGTH(column)-3 FOR 1)
WHERE column LIKE '%jnr' OR column LIKE '%snr'
PASTE is used to put in one character at position 3 from end,
CHAR_LENGTH to get length of column value,
UPPER converts character to upper case,
SUBSTRING is used to pick one character here (j or s),
LIKE is used to find values ending with jnr, or snr.
All ANSI SQL (no dbms specified!)

SQL Server Output to Text File Each Column Different Length Space Delimited

Let's say I have a SQL Server table that looks like the following:
ID NAME DESCRIPTION
1 ANDREW COOL
2 MATT NOT COOL
All I need to do is output the data to a space delimited text file. However I want to ensure that the 'NAME' column has at maximum 10 characters. So for example with the first row 'ANDREW' is is 6 characters, then I'd want 4 spaces after it.
Same thing for second row. 'MATT' is 4 characters, so I would want 6 spaces after it. This way as you move to each column the data is lined up, worst case it gets truncated but I'm not concerned with that.
Use this select query then export this to ur text file.
select ID,cast(NAME as char(10)) as NAME,DESCRIPTION from yourtable
you can use convert function
select CONVERT(char(10),'ANDREW')
.
select ID,
CONVERT((char(10),NAME) as NAME,
DESCRIPTION
from <table>

How to do string manipulation in SQL query

I know I'm close to figuring this out but need a little help. What I'm trying to do is all grab a column from a particular table, but chop off the first 4 characters. For example if in a column the value is "KPIT08L", the result I was is 08L. Here is what I have so far but not getting the desired results.
SELECT LEFT(FIELD_NAME, 4)
FROM TABLE_NAME
First up, left will give you the leftmost characters. If you want the characters starting at a specific location, you need to look into mid:
select mid (field_name,5) ...
Secondly, if you value performance,portability and scalability at all, this sort of "sub-column" manipulation should generally be avoided. It's usually far easier (and faster) to patch columns together than to split them apart.
In other words, keep the first four characters in their own column and the rest in a separate column, and do your selects on the relevant one. If you're using anything less than a full column, then it's technically not one attribute of the row.
Try with
SELECT MID(FIELD_NAME, 5) FROM TABLE_NAME
Mid is very powerfull, it let you select the starting point and all the remainder, or,
if specified, the length desidered as in
SELECT MID(FIELD_NAME, 5, 2) FROM TABLE_NAME ' gives 08 in your example text
SELECT RIGHT(FIELD_NAME,LEN(FIELD_NAME)-4)
FROM TABLE_NAME;
If it is for a generic string then the above one will work...
Don't have Access at my current location, but please try this.
SELECT RIGHT(FIELD_NAME, LEN(FIELD_NAME)-4)
FROM TABLE_NAME
The LEFT(FIELD_NAME, 4) will return the first 4 caracters of FIELD_NAME.
What you need to do is :
SELECT MID(FIELD_NAME, 5)
FROM TABLE_NAME
If you have a FIELD_NAME of 10 caracters, the function will return the 6 last caracters (chopping the first 4)!

SQL String contains ONLY

I have a table with a field that denotes whether the data in that row is valid or not. This field contains a string of undetermined length. I need a query that will only pull out rows where all the characters in this field are N. Some possible examples of this field.
NNNNNNNNNNNNNNNNNNN
NNNNNNNNNNNNNNNNNNNNNNN
NNNNNEEEENNNNNNNNNNNN
NNNNNOOOOOEEEENNNNNNNNNNNN
Any suggestions on a postcard please.
Many thanks
This should do the trick:
SELECT Field
FROM YourTable
WHERE Field NOT LIKE '%[^N]%' AND Field <> ''
What it's doing is a wildcard search, broken down:
The LIKE will find records where the field contains characters other than N in the field. So, we apply a NOT to that as we're only interested in records that do not contain characters other than N. Plus a condition to filter out blank values.
SELECT *
FROM mytable
WHERE field NOT LIKE '%[^N]%'
I don't know which SQL dialect you are using. For example Oracle has several functions you may use. With oracle you could use condition like :
WHERE LTRIM(field, 'N') = ''
The idea is to trim out all N's and see if the result is empty string. If you don't have LTRIM, check if you have some kind of TRANSLATE or REPLACE function to do the same thing.
Another way to do it could be to pick length of your field and then construct comparator value by padding empty string with N. Perhaps something like:
WHERE field = RPAD('', field, 'N)
Oracle pads that empty string with N's and picks number of pad characters from length of the second argument. Perhaps this works too:
WHERE field = RPAD('', LENGTH(field), 'N)
I haven't tested those, but hopefully that give you some ideas how to solve your problem. I guess that many of these solutions have bad performance if you have lot of rows and you don't have other WHERE conditions to select proper index.