Let's say I want to use the character 倀:
https://www.fileformat.info/info/unicode/char/20480/index.htm
How would I type this into a query in BigQuery with the proper escape sequence? My thought was the following, but this seems like it's not correct based on the Lexical Structure:
SELECT '倀', '\U00020480'
But obviously that's not correct as I'm getting:
How would I properly type it in with the escape code?
Consider below "hint"
SELECT '倀', CODE_POINTS_TO_STRING([00020480])
with output
Related
I'm using postgres full text search for (amoung other things) to provide autocomplete functionality for usernames and tags. However, I'd like autocomplete to match the column value 'dashed-tag-example' against a ts_query like 'dashedtag:*'.
My understanding is that, to do this without duplicating the column in my table I need to create a dictionary along the lines of the simple dictionary that strips charachters like '-'. Is it possible to create such a dictionary using SQL (i.e. something I could put in a rails migration)?
It seems like it should somehow be possible to define a dictionary (or do I need a parser?) that uses postgres's regexp substition functions but I can't seem to find any examples online of how to create a dictionary (parser?) like that. Is this possible? How?
The dictionary is too late; you would need a different parser, which would require writing C code.
The simple and pragmatic solution is to use replace() to strip the - when you construct the tsvector.
You don't need to create a new column for that, simply search like this:
SELECT ... FROM ...
WHERE to_tsvector('english', replace(col, '-', ''))
## to_tsquery('english', replace('search-string', '-' ''));
I would like to use a postgres tsquery on a column that has strings that all contain numbers, like this:
FRUIT-239476234
If I try to make a tsquery out of this:
select to_tsquery('FRUIT-239476234');
What I get is:
'fruit' & '-239476234'
I want to be able to search by just the numeric portion of this value like so:
239476234
It seems that it is unable to match this because it is interpreting my hyphen as a "negative sign" and doesn't think 239476234 matches -239476234. How can I tell postgres to treat all of my characters as text and not try to be smart about numbers and hyphens?
An answer from the future. Once version 13 of PostgreSQL is released, you will be able to do use the dict_int module to do this.
create extension dict_int ;
ALTER TEXT SEARCH DICTIONARY intdict (MAXLEN = 100, ABSVAL=true);
ALTER TEXT SEARCH CONFIGURATION english ALTER MAPPING FOR int WITH intdict;
select to_tsquery('FRUIT-239476234');
to_tsquery
-----------------------
'fruit' & '239476234'
But you would probably be better off creating your own TEXT SEARCH DICTIONARY as well as copying the 'english' CONFIGURATION and modifying the copy, rather than modifying the default ones in place. Otherwise you have the risk that upgrading will silently lose your changes.
If you don't want to wait for v13, you could back-patch this change and compile into your own version of the extension for a prior server.
This is done by the text search parser, which is not configurable (short of writing your own parser in C, which is supported).
The simplest solution is to pre-process all search strings by replacing - with a space.
Is there any way to escape SQL Like string when using "sqlLike" and "sqlLikeCaseInsensitive"?
Example: I want a match for "abc_123". Using "_______" (7 underscores) would also return "abcX123", how can I enforce "_" as the 4th character?
If you issue the query in persistence, this is actually not a mdriven issue but an SQL issue as mdriven converts the Expression into SQL. So if you really want to restrict the results to underscores only take a look to this question:
Why does using an Underscore character in a LIKE filter give me all the results?
The way to escape the underscore may depend on the needs of your SQL database as the different answers indicate.
I am using below code to do calculation
select column1 from tablename where code SIMILAR TO '%(-|_|–)EST[1-2][0-9](-|_)%'
for this column value -CSEST190-KCY18-04-01-L the condition was passed, but in actual I want to ignore this type of data.
The correct value which should pass through the above condition is
-CS-EST19-0-KCY18-04-01-L
-CS_EST19-0-KCY18-04-01-L
Any suggestions, how to avoid this type of confusion?
Easiest way is to go full-regex, instead of using SQL standard SIMILAR TO.
select column1 from tablename where code ~ '[_–-]EST[12][0-9][_-]'
Notice this is does not have to match the full string, and you don't have to add .* on both ends (equivalent of % in LIKE and SIMILAR TO). The reason you got a match on that is, because of the underscore _, which is a single wildcard character.
Also, I switched the order, in the square brackets, so that the dash is the last character. That way it's treated as a character literal, not as a range specifier.
I'm working on an iPhone app, which uses the SQLite database, and I'm trying to handle escape characters. I know that there is LIKE ESCAPE to handle escape characters in select statements, but in my application i have SELECT, INSERT, UPDATE actions and i really don't know how to go about handling escape characters.
if you are using sqlite3_exec() all-in-one function,
you dont need to use sqlite3_bind* functions..
just pass the string to sqlite3_mprintf() with %q token
sqlite3_mprintf("%q","it's example");
and the output string is
it''s example
Use FMDB, and then you won't have to. It has built-in parameter binding support, and that will take care of any escaping you need for you.
I believe you simply have to tell SQLite what your escape character is at the end of the SQL statement. For example:
SELECT * FROM MyTable WHERE RevenueChange LIKE '%0\%' ESCAPE '\'
The LIKE will match values such as 30%, 140%, etc. The character I used, \, could be anything.