I want to look for values in variable/column which start with 'S' and has 'gg' in between.
For instance Staggered is a word which starts with alphabet S and has gg in between the word.
so what sql query to write to get the result.
Due to the fact that you did not provide much meta information (which database?), I'll just show the following:
SELECT * FROM <table>
WHERE <columnname> LIKE 'S%gg%';
Good luck :)
As the target database is not mentioned, I will answer with Oracle syntax:
select *
from TABLE_NAME
where COL_NAME like 'S%gg%'
Related
I feel like this should be simple but I'm relatively unskilled in SQL and I can't seem to figure it out. I'm used to wrangling data in python (pandas) or Spark (usually pyspark) and this would be a one-liner in either of those. Specifically, I'm using Snowflake SQL, but I think this is probably relevant to a lot of flavors of SQL.
Essentially I just want to trim the first character off of a specific column. More generally, what I'm trying to do is replace a column with a substring of the same column. I would even settle for creating a new column that's a substring of an existing column. I can't figure out how to do any of these things.
On obvious solution would be to create a temporary table with something like
CREATE TEMPORARY TABLE tmp_sub AS
SELECT id_col, substr(id_col, 2, 10) AS id_col_sub FROM table1
and then join it back and write a new table
CREATE TABLE table2 AS
SELECT
b.id_col_sub as id_col,
a.some_col1, a.some_col2, ...
FROM table1 a
JOIN tmp_sub b
ON a.id_col = b.id_col
My tables have roughly a billion rows though and this feels extremely inefficient. Maybe I'm wrong? Maybe this is just the right way to do it? I guess I could replace the CREATE TABLE table2 AS... to INSERT OVERWRITE INTO table1 ... and at least that wouldn't store an extra copy of the whole thing.
Any thoughts and ideas are most welcome. I come at this humbly from the perspective of someone who is baffled by a language that so many people seem to have mastery over.
I'm not sure the exact syntax/functions in Snowflake but generally speaking there's a few different ways of achieving this.
I guess the general approach that would work universally is using the SUBSTRING function that's available in any database.
Assuming you have a table called Table1 with the following data:
+-------+-----------------------------------------+
Code | Desc
+-------+-----------------------------------------+
0001 | 1First Character Will be Removed
0002 | xCharacter to be Removed
+-------+-----------------------------------------+
The SQL code to remove the first character would be:
select SUBSTRING(Desc,2,len(desc)) from Table1
Please note that the "SUBSTRING" function may vary according to different databases. In Oracle for example the function is "SUBSTR". You just need to find the Snowflake correspondent.
Another approach that would work at least in SQLServer and MySQL would be using the "RIGHT" function
select RIGHT(Desc,len(Desc) - 1) from Table1
Based on your question I assume you actually want to update the actual data within the table. In that case you can use the same function above in an update statement.
update Table1 set Desc = SUBSTRING(Desc,2,len(desc))
You didn't try this?
UPDATE tableX
SET columnY = substr(columnY, 2, 10 ) ;
-Paul-
There is no need to specify the length, as is evidenced from the following simple test harness:
SELECT $1
,SUBSTR($1, 2)
,RIGHT($1, -2)
FROM VALUES
('abcde')
,('bcd')
,('cdef')
,('defghi')
,('e')
,('fg')
,('')
;
Both expressions here - SUBSTR(<col>, 2) and RIGHT(<col>, -2) - effectively remove the first character of the <col> column value.
As for the strategy of using UPDATE versus INSERT OVERWRITE, I do not believe that there will be any difference in performance or outcome, so I might opt for the UPDATE since it is simpler. So, in conclusion, I would use:
UPDATE tableX
SET columnY = SUBSTR(columnY, 2)
;
Consider this sample:
CREATE TABLE #tempTable
(name nvarchar(MAX))
INSERT INTO #tempTable VALUES (N'إِبْرَاهِيمُ'), (N'إبراهيم')
SELECT * FROM #tempTable WHERE name = N'إبراهيم'
SELECT * FROM #tempTable WHERE name LIKE N'%إبراهيم%'
Both selects only return إبراهيم but not إِبْرَاهِيمُ. How can I make it ignore these non-alphabetical characters in search? In other words, I want to get all similar words, including those with non-alpha characters.
You do not do it. Simple. NOTHING about arabic here - you have the same problem in english.
How can I make it ignore these non-alphabetical characters in search?
Like numbers? NOT AT ALL. Not with "standard SQL Syntax".
If you can, put a full text index on the field. And use the full text search syntax in your query. This is what it is for.
There is a thread over at sql stackexchange that has a workaround for this issue.
https://dba.stackexchange.com/questions/14153/treating-certain-arabic-characters-as-identical
Unfortunately, there is no case sensitive Arabic language, and of course, both select statements will return 'إبراهيم' because they were ordered to do that.
This is a problem we have been suffering from for a very long time, people always look for 'احمد' when it's written 'أحمد' and they won't find it.
this is a solution 100%:
$yourChaine = \Transliterator::create('NFC; [:Nonspacing Mark:] Remove; NFC')
->transliterate($yourChaine);
I am wondering if there is a way to write the SQL so that it would return me a result as usual but now, on the first row that would return also the attribute names.
To explain what I mean:
say you have a table "test" which has 2 attributes "id" and "name":
id name
1 nik
2 tst
query:
SELECT * FROM test;
produces:
1 nik
2 tst
but what I want it to return is this:
id name
1 nik
2 tst
Is this possible?
edit: I am using PostreSQL
You cannot return the names and the actual column values in a single result unless you give up on the real datatypes (which is probably not what you want).
Your example mixes character data and numeric data in the id column and Postgres will (rightfully) refuse to return such a result set.
Edit:
I tested the "union" solution given e.g. by JNK and it fails (as expected) on Postgres, Oracle and SQL Server precisely because of the non-matching datatypes. MySQL follows it's usual habits of not throwing errors and simply converts everything to characters.
Extremely generic answer since you don't provide an RDBMS:
SELECT id, name FROM(
SELECT 'id' as 'id', 'name' as 'name', 1 as 'Rank'
UNION ALL
SELECT *, 2 as 'Rank' FROM test) as X
ORDER BY [RANK]
EDIT
Thanks to Martin for pointing out the need for the ORDER BY
Assuming you are on SQL Server, you can get the column names of a specific table by using this query:
select column_name 'Column Name', data_type 'Data Type'
from information_schema.columns
where table_name = 'putYourTableNameHere'
Then, you'll have to UNION your things together.
I agree with OMG Ponies above, the way to get this meta-data is usually from the interface you use.
for example the Perl DBI module has a method fetchrow_hashref where the columns of the returned row are returned as an associative array (hash) where the colnames are the keys.
print $ref->{'name'}; # would print nik or tst
Update:
I had forgotten to add that some of these interface layers have a method that return s the col names and you could use that instead of adding the names into your result set.
The DBI method you'd use would be $sth->{NAMES}->[0] would return the first column name.
Depending on your tools / technique, but here are a couple:
If you're using SSMS (Sql-Server), and want to copy/paste your results with the column headers:
Query Window -->
R-Click
Results -->
Grid or Text -->
Check-mark the 'Include column headers in the result set' option
If you're using Sql-Server, you can query meta-tables (sys.columns, etc.)
If you're using an ASP.NET databound control, you usually have access to methods or properties (sqldatareader.getname(i), etc.)
Anyway -- just depends on the layer you're trying to get the names from -- if these above don't help, then edit / re-tag your question so we can focus on whatever tool you're wanting to use to do this.
EDIT for PostgresSQL
If you're using PostgresSQL, you can query meta-tables (information_schema.columns, etc.)
Can someone explain this to me? I have two queries below with their results.
query:
select * from tbl where contains([name], '"*he*" AND "*ca*"')
result-set:
Hertz Car Rental
Hemingyway's Cantina
query:
select * from tbl where contains([name], '"*he*" AND "*ar*"')
result-set:
nothing
The first query is what I would expect, however I would expect the second query to return "Hertz Car Rental". Am I fundamentally misunderstanding how '*' works in full-text searching?
Thanks!
I think SQL Server is interpreting your strings as prefix_terms. The asterisk is not a plain old wildcard specifier. Fulltext and Contains are word oriented. For what you are trying to do, you would be better off using plain old LIKE instead of CONTAINS.
http://msdn.microsoft.com/en-us/library/ms187787.aspx
"*" only works as a suffix. If you use it as a prefix, the table needs to be scanned no matter what and the index is useless. At that point, you might as well do
Select * From Table Where (Name Like '%he%') And (Name Like '%ar%')
I would try replacing * with % to see how it goes.
select * from tbl where contains([name], '"%he%" AND "%ar%"')
I have this query:
select * from table where column like '%firstword[something]secondword[something]thirdword%'
What do I replace [something] with to match an unknown number of spaces?
Edited to add: % will not work as it matches any character, not just spaces.
Perhaps somewhat optimistically assuming "unknown number" includes zero.
select *
from table where
REPLACE(column_name,' ','') like '%firstwordsecondwordthirdword%'
The following may help: http://blogs.msdn.com/b/sqlclr/archive/2005/06/29/regex.aspx
as it describes using regular expressions in SQL queries in SQL Server 2005
I would definitely suggest cleaning the input data instead, but this example may work when you call it as a function from the SELECT statement. Note that this will potentially be very expensive.
http://www.bigresource.com/MS_SQL-Replacing-multiple-spaces-with-a-single-space-9llmmF81.html