is there any way of getting accent insensitive results in a select query in DB2?
The version of my DB2 database is v6r1m0.
thanks
You could change the case of the column and the value you are looking for.
For example
Select upper(lastname)
From myTable
where upper(name) = upper('John')
You can use:
Upper
Translate
Ucase
However, I am not sure if these functions are available in your very old DB2 version. Plan to upgrade!
Related
How can I update my Postgresql database to be case insensitive ?
I already have like some tables and some data, and currently they are case sensitive but I would like to update all of them to be case insensitive.
You cannot get your database to be case insensitive, but from v12 on you can create a case insensitive ICU collation and use that with column definitions:
CREATE COLLATION english_ci (
PROVIDER = 'icu',
LOCALE = 'en-US#colStrength=secondary',
DETERMINISTIC = FALSE
);
That could be used like this:
CREATE TABLE testtab (ci_col text COLLATE english_ci);
Comparisons are case insensitive:
SELECT 'Hello' = 'hello' COLLATE english_ci;
?column?
══════════
t
(1 row)
There's a question about this related to emails that has useful insight: PostgreSQL: Case insensitive string comparison
Basically it seems there are a few approaches. You Can
Use lower() in indexes and make sure to use it on every query clause including this column.
Convert to citext (available in postgres 9) which internally compares by using lower() while retaining normal behavior of text otherwise.
Worst of all, probably, you could just force data to lower case on insert with a database trigger.
I wonder if someone could have an idea what is going wrong with this simple query on a hstore column in PostgreSQL 9.2
The queries are runned in pgAdmin
select attributeValue->"CODE_MUN" from shapefile_feature
returns: « attributevalue » column does not exists
when doing:
select * from shapefile_feature;
all the columns are returned including attributeValue, the hstore column
what is the problem?
PostgreSQL distinguish between "identifiers" and 'literal'. Identifiers are schema, table, column's, .. names, literals are others. A attribute in hstore are not SQL identifiers. So you have to pass their names as literals. Operator "->" is only shortcut for function "fetchval(hstore, text)" with possibility be indexed.
select attributeValue->'CODE_MUN' from shapefile_feature
is internally transformed to (don't do this transformation by self!)
select fetchval(attributeValue, 'CODE_MUN') from shapefile_feature
on buggy example in transformed form, you can better understand to error message:
select fetchval(attributeValue, "CODE_MUN") from shapefile_feature
PostgreSQL tries to find column "CODE_MUN" in shapefile_feature, bacause used double quotes means identifiers (in case sensitive notation).
In postgresql, I have mangaged to add wildcard pattern (*) to the query using SIMILAR TO option. So my query will be,
SELECT * FROM table WHERE columnName SIMILAR TO 'R*'
This query would return all entities starting from 'R' and not 'r'. I want to make it case insensitive.
Use ILIKE:
SELECT * FROM table WHERE columnName ILIKE 'R%';
or a case-insensitive regular expression:
SELECT * FROM table WHERE columnName ~* '^R.*';
Both are PostgreSQL extensions. Sanjaya has already outlined the standards-compliant approaches - filtering both sides with lower(...) or using a two-branch SIMILAR TO expression.
SIMILAR TO is less than lovely and best avoided. See this earlier answer.
You could write:
SELECT * FROM table WHERE columnName SIMILAR TO '(R|r)%'
but I don't particularly recommend using SIMILAR TO.
try
SELECT * FROM table WHERE columnName SIMILAR TO 'R%|r%'
I am looking to extract Sybase datatype for all the columns in a table. When I try to achieve this using $sth->{TYPE}, I get a numeric version of the datatype (i.e. instead of sybase datatype varchar, I get 0).
From the DBD::Sybase documentation, I noticed that SYBTYPE attribute of syb_describe function might be able to produce what I am looking for. But it seems that my understanding is not proper. SYBTYPE also prints datatype in numeric form only.
Is there any way to fetch the textual representation of actual Sybase datatype (instead of the number)?
It sounds like you wish to reverse engineer the create table definition. Here is an SQL script you can use for Sybase or SQL Server tables.
select c.name,
"type(size)"=case
when t.name in ("char", "varchar") then
t.name + "(" + rtrim(convert(char(3), c.length)) + ")"
else t.name
end,
"null"=case
when convert(bit, (c.status & 8)) = 0 then "NOT NULL"
else "NULL"
end
from syscolumns c, systypes t
where c.id = object_id("my_table_name")
and c.usertype *= t.usertype
order by c.colid
go
Note: This could still be edited with a nawk script to create a real SQL schema file.
The nawk script would strip the header, add "create table my_table_name", add commas, strip the footer and add a "go".
Good SQL, good night!
I found a workaround (Note: This does not answer the question though):
What I did was simply joined the sysobjects, systypes and syscolumns system tables.
Which is the fastest way to search within string in PostgreSQL (case insensivity):
SELECT col FROM table WHERE another_col ILIKE '%typed%'
or
SELECT col FROM table WHERE another_col ~* 'typed'
How can I turn on showing the time which query need to return results? Something like is on default in mySQL (I am thinking about CLI client).
Both queries are the same, PostgreSQL rewrites ILIKE to ~*. Check the results from EXPLAIN to see this behaviour.
I'm not sure about your question, but the psql-client can show you some timing of the query, using \timing.
Regarding the timing:
One solution is to use the switch for psql that Frank has already mentioned.
When you use EXPLAIN ANALZYE it also includes the total runtime of the query on the server.
I prefer this when comparing the runtime for different versions of a query as it removes the network from the equation.