I have tried using a combination of both of these two previous questions Question 1 Question 2 to help me with my issue.
My issue is I am trying to set one column in DB2 equal to another column with a beginning and ending value. I do have the option of doing this in two steps, of adding the S- first and then on a second pass add the -000 on the end, but I am currently running into the issue of CONCAT not working in DB2 like in MYSQL.
Pre-conversion
name | loc | group
-----------------------------------
sam | 123 |
jack | 456 |
jill | 987 |
mark | 456 |
allen | 123 |
john | 789 |
tom | 123 |
Post-conversion
name | loc | group
-----------------------------------
sam | 123 | S-123-000
jack | 456 | S-456-000
jill | 987 | S-987-000
mark | 456 | S-456-000
allen | 123 | S-123-000
john | 789 | S-789-000
tom | 123 | S-123-000
The SQL I am trying to use:
UPDATE table
SET GROUP = CONCAT('S-',LOC,'-000')
WHERE LENGTH(RTRIM(LOC)) = 3
Any help or guidance would be appreciated.
The DB2 CONCAT takes only two arguments, so you could nest them to achieve your desired result.
UPDATE table
SET GROUP = CONCAT(CONCAT('S-',LOC),'-000')
WHERE LENGTH(RTRIM(LOC)) = 3
There is also a concatenate operator: ||
However some recommend not to use it
UPDATE table
SET GROUP = 'S-'||LOC||'-000'
WHERE LENGTH(RTRIM(LOC)) = 3
If you're LOC field is longer than 3 and you want no whitespace
UPDATE table
SET GROUP = 'S-'||RTRIM(LOC)||'-000'
WHERE LENGTH(RTRIM(LOC)) = 3
Related
I have table which consist of 35,000 records in which half of the rows have name as null value
If the field has null value, i want to update the field with the value of username.
Can anyone help me with this ?
This is sample table
name | username | idnumber | type
----------------------------------------------
-- | jack | 1 | A
Mark | Mark | 2 | B
-- | dev | 3 | A
After update i want it to look like this
name | username | idnumber | type
----------------------------------------------
jack | jack | 1 | A
Mark | Mark | 2 | B
dev | dev | 3 | A
You seem to want:
update t
set name = username
where name is null;
Note that -- is not a typical representation of NULL values. You might consider <null> for instance.
I have a table (e.g. Users) in PostgreSQL database. Its size is relatively large (ca. 4 GB of data) and I would like to get a table/result consisting of single rows fulfilling the select query. This query shall be executed for each element in an array of strings (couple dozens of elements).
Example single select for one element:
SELECT * FROM "Users" WHERE "Surname" LIKE 'Smith%' LIMIT 1
Value between ' and %' should be an element of input array.
EDIT: It doesn't matter for me whether I get record no. 1 or 2 for LIKE 'Smith%'
How can I achieve this?
I tried to append query results to some array variable within FOREACH loop but with no success.
Example source table:
| Id | Name | Surname |
|---- |-------- |---------- |
| 1 | John | Smiths |
| 2 | Adam | Smith |
| 3 | George | Kowalsky |
| 4 | George | Kowalsky |
| 5 | Susan | Connor |
| 6 | Clare | Connory |
| 7 | Susan | Connor |
And for ['Smith', 'Connor'] the output is:
| Id | Name | Surname |
|----|-------|---------|
| 1 | John | Smiths |
| 5 | Susan | Connor |
In Postgres you can use the ANY operator to compare a single value to all values of an array. This also works with together with the LIKE operator.
SELECT *
FROM "Users"
WHERE "Surname" like ANY (array['Smith%', 'Connor%'])
Note that LIKE is case sensitive, if you don't want that, you can use ILIKE
This will show you the logic. Syntax is up to you.
where 1 = 2
start of loop
or surname like 'Array Element goes here%'
end of loop
I am working on a project and for my login credentials checking process I am trying to create a view in which the name,surname,username and password of customers,workers and admins are stored so that I can search faster and I have two questions.
Do you think it is a good idea to do that ?
If yes, can you help me how to do that?
Thank you in advance.
1) yes, but for simplicity rather than performance (and a few other reasons)
2) CREATE OR REPLACE VIEW viewname AS your_select_statement;
If the front-end is a single interface for both customers and employees then the tables should not be separated in the first place. If you have a person who is both a customer and a worker then they would appear on two tables and it is possible the data would not be synchronized between the two and if you create a view then they would appear twice. Instead create a single table for all people and have separate tables for data specific to customers, workers and admins.
Something like:
People
id | firstname | surname | username | password_hash | password_salt
--------------------------------------------------------------------
1 | alice | abbot | aa | abc | 123
2 | bob | barnes | bb | def | 456
3 | charlotte | carol | cc | ghi | 789
4 | daniel | david | dd | jkl | 036
Customers
id | Credit_Limit | has_Trade_Account
-------------------------------------
2 | 0 | 0
3 | 2000 | 1
Workers
id | Joining_Date | Grade
--------------------------
1 | 2015-01-01 | 5
3 | 2000-12-25 | 3
Admins
id | Edit_Permissions
----------------------
3 | Orders
3 | Stock
Example data rows:
| ID | First Name | Last Name | Federal Race Code |
| 101 | Bob | Miller | 01010 |
| 102 | Daniel | Smith | 00011 |
The "Federal Race Code" field contains binary data, and each "1" is used to determine if a particular check box is set on a particular web form. E.g., the first bit is American Indian, second bit is Asian, third bit is African American, fourth is Pacific Islander, and the fifth is White.
I need to generate a separate row for each bit that is set to "1". So, given the example above, I need to generate output that looks like this:
| ID | First Name | Last Name | Mapped Race Name |
| 101 | Bob | Miller | Asian |
| 101 | Bob | Miller | African American |
| 102 | Daniel | Smith | Pacific Islander |
| 102 | Daniel | Smith | White |
Any tips or ideas on how to go about this?
You can do it with either 6 queries with UNION or one UNPIVOT clause.
In any case you should start by splitting that binary logic into 6 columns:
SELECT *,
CASE WHEN federal_race_code & 16 = 16 THEN 1 ELSE 0 END as NativeAmerican,
..
CASE WHEN federal_race_code & 1 = 1 THEN 1 ELSE 0 END as White
FROM myTable
Then UNION:
SELECT *, 'Native American' AS Race
FROM (<subquery>)
WHERE NativeAmerican = 1
UNION
...
UNION
SELECT *, 'White' AS Race
FROM (<subquery>)
WHERE White = 1
If you are on Oracle or SQL server use CTE.
I have a table with information like this.
ID | Name | #ofCow | UItem | place
--------+---------+-------- +---------+----------
0 | Bob | 7 | 1 | maine
1 | Bob | 3 | 5 | new york
2 | Tom | 2 | 5 | cali
I wish to produce a table like this where it would add up the number of cows and Uitem if the name is the same. However my select query seems to not be working. I suspect it is because the place column is the problem. Since you can't add 'Maine' and 'New York' together. Can anyone help me find a solution ?
ID | Name | #ofCow | UItem |
--------+---------+-------- +---------+
0 | Bob | 10 | 6 |
2 | Tom | 2 | 5 |
TLDR : Add the values in two columns in table 1 if name is same. Output in another column. Don't show the two columns. I don't need places also.
You could use this (I have considered the name of the table as HolyCow) :
SELECT holy.ID,
holy.Name,
SUM(holy.Cows) as '#ofCow',
SUM(holy.UItem) as 'UItem'
FROM HolyCow holy
GROUP BY holy.ID, holy.Name
ORDER BY holy.Name
Hope this helps!!