I am filling data adapter directly with PostgreSQL query so I can't add strings when read through query results. But I need added text from two columns.
Say I have data:
doc_id: 1,
doc_type: Bill,
doc_number: 145/2013
doc_price: 100.00
Those are 4 columns and I need 3 columns in result:
1 | Bill 145/2013 | 100.00
where doc_type and doc_number are strings and should be added like strings
doc_type + 1 space + doc_number
Is this possible to do with SELECT query?
Something like this
SELECT doc_id, doc_type + " " + doc_number, doc_price FROM... WHERE...
For sure you can:
SELECT doc_id, doc_type || ' ' || doc_number as mynewFieldName, doc_price FROM... WHERE...
The string concatenation operator in PostgreSQL is || while the string delimiter is'
Related
I have a table with an integer column. It has 12 records numbered 1000 to 1012. Remember, these are ints.
This query returns, as expected, 12 results:
select count(*) from proposals where qd_number::text like '%10%'
as does this:
SELECT COUNT(*) FROM "proposals" WHERE (lower(first_name) LIKE '%10%' OR qd_number::text LIKE '%10%' )
but this query returns 2 records:
SELECT COUNT(*) FROM "proposals" WHERE (lower(first_name) || ' ' || qd_number::text LIKE '%10%' )
which implies using || in concatenated where expressions is not equivalent to using OR. Is that correct or am I missing something else here?
You probably have nulls in first_name. For these records (lower(first_name) || ' ' || qd_number::text results in null, so you don't find the numbers any longer.
using || in concatenated where expressions is not equivalent to using ORIs that correct or am I missing something else here?
That is correct.
|| is the string concatenation operator in SQL, not the OR operator.
I have a column "pnum" in a "test" table.
I'd like to replace the leading "9" in pnum with "*" for every record.
testdb=# select * from test limit 5;
id name pnum
===========================================
1 jk 912312345
2 tt 9912333333
I would like the pnums to look like this:
id name pnum
===========================================
1 jk *12312345
2 tt *912333333
How would I do something like this in postgres?
EDIT 1:
I have tried something like this so far:
select id, name, '*' && substring(pnum FROM 2 FOR CHAR_LENGTH(pnum)-1 ) from test limit 3;
Also tried this:
select id, name, '*' || substring(pnum FROM 2 FOR CHAR_LENGTH(pnum)-1 ) from test limit 3;
Neither one has worked...
EDIT 2:
I figured it out:
select id, name, '*'::text || substring(pnum FROM 2 FOR CHAR_LENGTH(pnum)-1 ) from test limit 3;
See function regexp_replace(string text, pattern text, replacement text [, flags text]) String Functions and Operators
SELECT regexp_replace('9912333333', '^[9]', '*');
regexp_replace
----------------
*912333333
You can use Postgres' string manipulation functions for this. In your case "Substring" and "Char_Length"
'*' || Substring(<yourfield> FROM 2 FOR CHAR_LENGTH(<yourfield>)-1) as outputfield
I am trying to normalize my tables to make the db more efficient.
To do this I have removed several columns from a table that I was updating several columns on.
Here is the original query when all the columns were in the table:
UPDATE myActDataBaselDataTable
set [Correct Arrears 2]=(case when [Maturity Date]='' then 0 else datediff(d,convert(datetime,#DataDate, 102),convert(datetime,[Maturity Date],102)) end)
from myActDataBaselDataTable
Now I have removed [Maturity Date] from the table myActDataBaselDataTable and it's necessary to retrieve that column from the base reference table ACTData, where it is called Mat.
In my table myActDataBaselDataTable the Account number field is a concatenation of 3 fields in ACTData, thus
myActDataBaselDataTable.[Account No]=ac.[Unit] + ' ' + ac.[ACNo] + ' ' + ac.[Suffix]
(where ac is the alias for ACTData)
So, having looked at the answers given elsewhere on SO (such as 1604091: update-a-table-using-join-in-sql-server), I tried to modify this particular update statement as below, but I cannot get it right:
UPDATE myActDataBaselDataTable
set dt.[Correct Arrears 2]=(
case when ac.[Mat]=''
then 0
else datediff(d,convert(datetime,'2014-04-30', 102),convert(datetime,ac.[Mat],102))
end)
from ACTData ac
inner join myActDataBaselDataTable dt
ON dt.[Account No]=ac.[Unit] + ' ' + ac.[ACNo] + ' ' + ac.[Suffix]
I either get an Incorrect syntax near 'From' error, or The multi-part identifier "dt.Correct Arrears 2" could not be bound.
I'd be grateful for any guidance on how to get this right, or suugestiopns about how to do it better.
thanks
EDIT:
BTW, when I run the below as a SELECT it returns data with no errors:
select case when [ac].[Mat]=''
then 0
else datediff(d,convert(datetime,'2014-04-30', 102),convert(datetime,[ac].[Mat],102))
end
from ACTData ac
inner join myActDataBaselDataTable dt
ON dt.[Account No]=ac.[Unit] + ' ' + ac.[ACNo] + ' ' + ac.[Suffix]
In a join update, update the alias
update dt
What is confusing is that in later versions of SQL you don't need to use the alias in the update line
So I have a in my Postgresql:
TAG_TABLE
==========================
id tag_name
--------------------------
1 aaa
2 bbb
3 ccc
To simplify my problem,
What I want to do is SELECT 'id' from TAG_TABLE when a string "aaaaaaaa" contains the 'tag_name'.
So ideally, it should only return "1", which is the ID for tag name 'aaa'
This is what I am doing so far:
SELECT id FROM TAG_TABLE WHERE 'aaaaaaaaaaa' LIKE '%tag_name%'
But obviously, this does not work, since the postgres thinks that '%tag_name%' means a pattern containing the substring 'tag_name' instead of the actual data value under that column.
How do I pass the tag_name to the pattern??
You should use tag_name outside of quotes; then it's interpreted as a field of the record. Concatenate using '||' with the literal percent signs:
SELECT id FROM TAG_TABLE WHERE 'aaaaaaaa' LIKE '%' || tag_name || '%';
And remember that LIKE is case-sensitive. If you need a case-insensitive comparison, you could do this:
SELECT id FROM TAG_TABLE WHERE 'aaaaaaaa' LIKE '%' || LOWER(tag_name) || '%';
A proper way to search for a substring is to use position function instead of like expression, which requires escaping %, _ and an escape character (\ by default):
SELECT id FROM TAG_TABLE WHERE position(tag_name in 'aaaaaaaaaaa')>0;
I personally prefer the simpler syntax of the ~ operator.
SELECT id FROM TAG_TABLE WHERE 'aaaaaaaa' ~ tag_name;
Worth reading through Difference between LIKE and ~ in Postgres to understand the difference.
`
In addition to the solution with 'aaaaaaaa' LIKE '%' || tag_name || '%' there
are position (reversed order of args) and strpos.
SELECT id FROM TAG_TABLE WHERE strpos('aaaaaaaa', tag_name) > 0
Besides what is more efficient (LIKE looks less efficient, but an index might change things), there is a very minor issue with LIKE: tag_name of course should not contain % and especially _ (single char wildcard), to give no false positives.
SELECT id FROM TAG_TABLE WHERE 'aaaaaaaa' LIKE '%' || "tag_name" || '%';
tag_name should be in quotation otherwise it will give error as tag_name doest not exist
Question about a query I'm trying to write in SQL Server Management Studio 2008. I am pulling 2 rows. The first row being the header information, the second row being the information for a certain Line Item. Keep in mind, the actual header information reads as "Column 0, 1, 2, 3, 4,.... etc."
The data looks something like this:
ROW 1: Model # | Item Description| XS | S | M | L | XL|
ROW 2: 3241 | Gray Sweatshirt| | 20 | 20 | 30 | |
Basically this shows that there are 20 smalls, 20 mediums, and 30 larges of this particular item. There are no XS's or XL's.
I want to create a subquery that puts this information in one row, but at the same time, disinclude the sizes with a blank quantity amount as shown under the XS and XL sizes.
I want it to look like this when all is said and done:
ROW 1: MODEL #| 3241 | ITEM DESCRIPTION | Gray Sweatshirt | S | 10 | M | 20 | L | 30 |
Notice there are no XS or XL's included. How do I do make it so those columns do not appear?
Since you are not posting your query, nor your table structure, I guess it is with columns Id, Description, Size. If so, you could do this and just replace with your table and column names:
DECLARE #columns varchar(8000)
SELECT #columns = COALESCE (#columns + ',[' + cast(Size as varchar) + ']', '[' + cast(Size as varchar) + ']' )
FROM YourTableName
WHERE COUNT(Size) > 0
DECLARE #query varchar(8000) = 'SELECT Id, Description, '
+ #columns +'
FROM
(SELECT Id, Description, Size
FROM YourTableName) AS Source
PIVOT
(
COUNT(Size)
FOR Size IN ('+ #columns +')
) AS Pvt'
EXEC(#query)
Anyhow, I also agree with #MichaelFredickson. I have implemented this pivot solution, yet it is absolutely better to let the presentation layer to take care of this after just pulling the raw data from SQL. If not, you would be processing the data twice, one on SQL to create the table and the other in the presentation when reading and displaying the values with your c#/vb/other code.