I have an employees table and I want to add a third column valued as the concatenation of the first and last name called "FullName". How can I accomplish that without losing any data from either of the first two columns?
Quick preface: this answer was based on the originally incorrect tag that this question was relating to SQL Server. I'm no longer aware of its validity on Oracle SQL Developer.
ALTER TABLE Employees ADD FullName AS (FirstName + ' ' + LastName)
Although in practice I'd advise that you do that operation in your SELECT. That's somewhat personal preference, but I tend to think doing things in your end queries is a bit cleaner, more readable, and easier to maintain than storing extra, calculated columns.
Edit:
This was eventually found as the answer, and listed by the OP as a comment on this post. The following is appropriate syntax for Oracle Sql Database.
ALTER TABLE emps MODIFY (FULL_NAME VARCHAR2(50) GENERATED ALWAYS AS (first_name || ' ' || last_name) VIRTUAL);
If you need fullname column all time when you select from database then you can create computed column at the time of creation of your table employee.
for example:
CREATE TABLE Employee
(
FirstName VARCHAR(20),
LastName VARCHAR(20),
FullName AS CONCAT(FirstName,' ',LastName)
)
INSERT INTO Employee VALUES ('Rocky','Jeo')
SELECT * FROM Employee
Output:
FirstName LastName FullName
Rocky Jeo Rocky Jeo
It depends on your purpose, whether you really need to add a new column to your database, or you just need to query out the "full name" on an as-needed basis.
To view it on the fly, just run the query
SELECT firstname + ' ' + lastname AS FullName FROM employees
Beyond that, you also can create a simple Stored Procedure to store it.
(For single result use equal to in the where condition)
select *
from TABLE_name
where (Column1+Column2) in (11361+280,11365+250)
In addition to #Jacky 's answer, if you are trying to add this to a query and not the table, there is also the CONCAT() function that you can use in the select statement
SELECT CONCAT(FirstName, ' ', LastName) as FullName
FROM table_name
Related
I am new to SQL, which is perhaps why I have not been able to locate a solution to the following problem.
I have this database table where all columns are of type VARCHAR(50):
And I want to update the values in FullName so that they are a combination of FirstName and LastName, separated by a space.
This is what I would like to end up with:
I do not want to update each row manually.
I do not want to update each row manually.
I will show you two solutions:
UPDATE the column with a single statement. It's not really such a hassle:
UPDATE Names
SET FullName = FirstName + ' ' + LastName;
-- or: … = CONCAT(FirstName, ' ', LastName);
You said that all your columns are defined as VARCHAR(50), so take note that FirstName + ' ' + LastName could reach a maximum length of 50 + 1 + 50 = 101 characters. Therefore there is the possibility that FullName gets truncated: That column will only store the first 50 characters (or less); if there are more, they get thrown away. So you might want to re-define FullName as VARCHAR(101).
Alternatively, turn FullName into a computed column:
ALTER TABLE Names
DROP COLUMN FullName;
ALTER TABLE Names
ADD FullName AS (FirstName + ' ' + LastName);
This solution has three distinct advantages:
FullName can never contradict FirstName and LastName, because it is automatically derived (at the time of querying it) from them via the specified expression.
There is no danger of string truncation, as with the above solution. Note that you do not need to specify a type for FullName; SQL Server figures it out automatically, based on the expression.
FullName will not take up any storage space (unless perhaps when it is included in an index).
I have a column in my table called display name and the data looks like this John Smith I am looking to see if there is away to split the data like so:
display name as first name => John, display name as last name => Smith
Is this possible?
Assuming MySQL, something like this should work if you always have a single space.
SELECT Substr(name, 1, Instr(name, ' ')) as FirstName,
Substr(name, Instr(name, ' ')) as LastName
FROM DisplayName
Here is some sample Fiddle that shows you how it works (and when it doesn't).
Good luck.
There are multiple solutions available for this common issue. If you are just querying the DB, then you can use the example provided by #sgeddes.
Now if you would like to take the values you get from that query and put it, in its own column, you will want to create a new column;
alter table table_name
add column first_name varchar(30) COLLATE utf8_unicode_ci DEFAULT NULL
after col_name;
⬆️ The after statement help you choose the location of your new column.
Then you can update said column with an update statement;
update table_name
set first_name = SUBSTRING_INDEX(SUBSTRING_INDEX(display_name, ' ', 1), ' ', -1)
This worked for me. Good luck 🍀
I want to write a query in T-SQL to perform a search on two concatenated columns. The two columns are fname and lname. Here is what I have so far:
SELECT
fname,
lname,
...
FROM
users
JOIN
othertable ON foo=bar
WHERE
fname+' '+lname LIKE '%query%'
SQL server doesn't like that syntax, though. How do I structure the query so that I can perform a WHERE LIKE operation that searches through two concatenated columns, allowing me to search the user's full name, rather than just first name and last name individually?
I can only suggest that one of fname or lname is NULL so the LIKE fails., (NULL concat anything is null)
Try
...
ISNULL(fname, '') + ' ' + ISNULL(lname, '') LIKE '%query%'
However, I would use a computed column and consider indexing it because this will run awfully.
My suggestion is to add a calculated column to your table for full_name
calculated column examples:
--drop table #test
create table #test (test varchar (10) , test2 varchar (5),[Calc] AS right(test, 3))
Insert #test
values('hello', 'Bye')
Insert #test
values('hello-bye', null)
Alter table #test
add [MyComputedColumn] AS substring(test,charindex('-',test), len(test)),
Concatenatedcolum as test+ ' ' +test2
select * from #test
As you can see you may have to play around a bit until you get the results you want. Do that in a temp table first to avoid having to restructure the database table multiple times. For names, especially if you are using middle name which is often blank, you may need to add some code to handle nulls. You may also need to have code sometimes to cast to the same datatype if one filed you are concatenating is an int for instance and the other a varchar.
I think one of the join conditions might be causing a problem. Try rewriting it, you may find the error goes away ;)
Just started a tutorial in SQL for beginners. I'm doing some exercises now and I would like to know how to change the title.
If you look at here: you'll see that I have made firstname, lastname, title, age and salary. And I wrote the letters in small letter.
How can I change it to capital letter?
http://tinypic.com/r/amtpgm/3
I tried using this:
update mytablename
set firstname = 'Firstname'
where firstname = 'firstname'
But I later realized that this one will not work.
Thanks
====
additional question:
I also notice that if I wrote with spaces, then its not recognized. It's the first part only which will be displayed. Do you know why is it doing? Thanks
create table myemployees_tr0214
(First Name varchar(20),
Last Name varchar(20),
Title char(5),
Age number(3),
Salary number(6,10));
==========
thank you for all your inputs.
I've tried this one in renaming the "Firstname" to "Fname" and it didn't work. Did I miss something?
alter table myemployees_tr0214
rename column Firstname to Fname;
This should update all the firstnames in the table to an uppercase first letter:
UPDATE mytablename SET firstname = CONCAT(UCASE(MID(firstname,1,1)),MID(firstname,2));
Hope this helps you :)
First, unless you really want to change the names of the fields, don't. It's not really all that important if all you're doing is learning SQL. Note that if you want to learn the syntax for doing so, then of course it would be a worthwhile exercise, but other than that, I'd let it be.
Your edited question mentions using spaces in names. This is not allowed. The rules for what constitutes a "SQL Identifier", be it the name of a table, column, constraint, etc. has some strict rules, and simplified they are that you should only use letters, underscores, and digits, except that you can't start with a digit.
Now, why the online website that you're using to learn SQL through doesn't complain when you add those spaces, that I don't know, and to me that makes it a little suspect. It doesn't sound as though it actually uses a known database engine, as just the presence of those spaces there + the extra words would make any normal database engine complain about bad syntax.
In order to fix it, either add underscores instead of spaces, or contract and use camelCasing, like this: FirstName, LastName
Ah, there are two ways to read this question. The first is based on reading the sample UPDATE you posted. This will fail because SQL by default doesn't do a case sensitive comparison on strings.
The second piece of code implies what you wanted was to ALTER TABLE and change the name of the column from a column name with one casing to another. In MS-SQL, you can't do that without dropping the whole table and re-creating it, in other dialects of SQL there will be version specific DDL syntax.
And finally, in MS-Access, if a column name has a space, you wrap it in double quotes, e.g. "My Column" in SQL wrap it in [My Column]
update mytablename set firstname = 'Firstname'; where firstname = 'firstname';
This will update the values of the firstname column. What you are trying to do is change the name of the firstname column. How to do this depends on the database you're using (which you haven't mentioned).
If it's MS Access or SQL server, you can open the table in the UI and use the designer to change the column name.
Otherwise you can use the SQL ALTER TABLE statement, as described here.
For MS SQL Server...
You'd use [ and ] to delimit identifiers:
create table myemployees_tr0214 (
[First Name] varchar(20), --here
[Last Name] varchar(20), --here
Title char(5),
Age number(3),
Salary number(6,10)
);
If you want to change the column name from "firstname" to "Firstname", you could use sp_rename in MS SQL Server.
If you want to change the first letter of the data in the "firstname" column, other posters have offered solutions and here's another for a single name.
update mytablename
set firstname = 'Firstname'
where firstname COLLATE Latin1_general_Bin = 'firstname' COLLATE Latin1_general_Bin
If you're using mysql see: http://dev.mysql.com/doc/refman/5.0/en/charset-binary-op.html
The BINARY operator casts the string
following it to a binary string. This
is an easy way to force a comparison
to be done byte by byte rather than
character by character. BINARY also
causes trailing spaces to be
significant
mysql> SELECT 'a' = 'A';
-> 1
mysql> SELECT BINARY 'a' = 'A';
-> 0
mysql> SELECT 'a' = 'a ';
-> 1
mysql> SELECT BINARY 'a' = 'a ';
-> 0
you'll need some kind of unique row indentifier like id so you can do
update mytablename set firstname = 'Firstname' where id = 1
now what can be used as a unique row indentifier is a huge debate of natural vs surrogate keys. use what you think is best for your example but i'm a supporter of surogate keys since every natural key has the possibility to change.
This may need to be optimize for more but it will allow you to even update mulitple first name MSSQL version
select 'mary ellen' as firstname into #test
insert into #test select 'Nathan'
select
Case when patindex('% %',firstname) >0 then
upper(left(firstname,1)) --first letter
+ rtrim(substring(firstname,2,patindex('% %',firstname)-1)) --whole firstname
+ ' ' -- space
+ Upper(substring(firstname,patindex('% %',firstname)+1,1)) --first letter last name
+ rtrim(substring(firstname,patindex('% %',firstname)+2, len(firstname)))
else
upper(left(firstname,1)) + substring(firstname,2,len(firstname))
end as firstname
from #test
update #test
set firstname = Case when patindex('% %',firstname) >0 then
upper(left(firstname,1)) --first letter
+ rtrim(substring(firstname,2,patindex('% %',firstname)-1)) --whole firstname
+ ' ' -- space
+ Upper(substring(firstname,patindex('% %',firstname)+1,1)) --first letter last name
+ rtrim(substring(firstname,patindex('% %',firstname)+2, len(firstname)))
else
upper(left(firstname,1)) + substring(firstname,2,len(firstname))
end
Working on parsing a bunch of databases put together in an older, more freewheeling time into a new schema. Basically it's one database per year, with database names like foo98, foo99, foo2000, etc.
So for the most recent foo data, I can do something like
SELECT foo_person.mdname AS middle_name,
...
FROM foo_person, foo_place, foo_thing
As you get back into earlier versions of the foo database, middle name isn't stored. I've tried to build a kind of universal query, something like:
SELECT IFNULL(foo_person.mdname, "") AS middle_name,
...
FROM foo_person, foo_place, foo_thing
but MySQL complains about unknown column foo_person.mdname, which is entirely reasonable as it doesn't exist.
Is there some way to handle non-existent columns with just MySQL syntax, or will I have to write database-specific import queries?
There isn't any way of handling a non-existent column in sql (as opposed to an empty column).
You can tell whether the column is there or not using the information_schema tables, like so:
select * from information_schema.columns
where table_name='mytable' and table_schema='mydatabase';
Yes there is a way.
Let's consider these databases
DB2009 has Person with Fname, MInitial and LName
DB2008 has Person with Fname and LName
DB2007 has Person with PersonName
You can do something similar the following (I wrote this for MS SQL Server)
/*all three columns exist*/
SELECT FName, MInitial, LName
From DB2009.Person
UNION
/*one column is a forced null */
SELECT FName, NULL as MInitial, LName
From DB2008.Person
UNION
/*two columns are derived and one column is a forced null */
SELECT SubString (1, CharIndex (PersonName, ' '), PersonName) as FirstName,
NULL as MInitial,
SubString (CharIndex (PersonName, ' '), len (PersonName), PersonName),
From DB2007.Person
Could you rename the tables and create views in their place with the missing columns?
Not sure if this is what you're looking for, but thought I would suggest it.
-- Here is your original table
create table t (fname varchar(30), lname varchar(30));
-- Rename it to something else
alter table t rename to tOrig;
-- Create a view with the columns its missing that you need
create view t as select fname, lname, '' as mname from tOrig;
If you're working with heterogenous databases, I would use database-specific import queries anyways. You might need to join some columns and remove some, and truncate some, etc.
Instead of making more complex sql queries, perhaps it would be better to
alter the foo98 and foo99 tables to add in the missing columns.
For example, to add a column of type varchar(30) called "mdname" to foo98:
ALTER TABLE foo98 ADD mdname varchar(30) AFTER first_name;
Then you can relax and use the same simple SQL query no matter which tabel is being accessed.