Questions tagged [string-searching]
For questions about searching a string for matches
80
questions
0
votes
0
answers
35
views
SQL search for a pattern in the middle of a string (infix search) without full table scan
With SQL, I need to select rows which have a pattern like %hello% (i.e. <anything>hello<anything>) in a column, with potentially 100 millions of rows or more.
In the answer Infix search in ...
- 161
2
votes
3
answers
300
views
EXPLAIN ANALYZE does not show what takes time with my GIN index scan
Context
I have a table named companies_establishments that holds ~33M rows.
I created a GIN index with trigrams, so I can make LIKE queries much faster.
CREATE INDEX companies_establishments_id_index ...
- 123
0
votes
2
answers
76
views
Using a WHERE colname NOT LIKE (select * from otherTable)
So in essence what im trying to do is this:
Given TBL1 (around 8,000 rows)
letters
abababa
bcbcbcb
cdcdcdc
and TBL2 (around 2,000 rows)
letters
ab
bc
I want to write a query to find every row ...
5
votes
1
answer
254
views
postgresql matching or converting utf-8 variant strings
Postgres 13
I am looking for a way to search UTF-8 text that may have variant character representations ( what is the proper term for this? ie 𝐋𝐈𝐅𝐄 vs life ) within postgresql.
I am running into ...
- 153
1
vote
1
answer
277
views
Case sensitivity not working
I have an issue where I keep getting the value 'CtP_PETER_Fact' out of the query below. It should be a case sensitive where-clause. I tried it in a few different ways: setting the COLLATE statement ...
- 495
0
votes
1
answer
174
views
List and count words from a column
I have a column with strings containing a list of species:
+----------------------------------------+
| species |
+----------------------------------------+
| Dinosauria,...
- 113
1
vote
0
answers
458
views
Optimize select query with OR and ILIKE
I have the following query for my PostgreSQL 13 database:
SELECT * FROM "user"
INNER JOIN "comment" on "comment"."user_id" = "user"."id"
...
- 11
2
votes
0
answers
167
views
Full text index search with character at the beginning
I am looking at tables like this (I did not design them):
CREATE TABLE EventIDsToSearch (id int not null)
insert into EventIDsToSearch values (1)
insert into EventIDsToSearch values (92)
insert into ...
- 503
-1
votes
1
answer
34
views
How should I construct a "custom synonyms" table?
I have a table called diary. I insert several messages into it almost every day.
I sometimes, for example, call Microsoft "Microjunk", "Micro$oft", "M$" and many other ...
- 51
0
votes
1
answer
559
views
Understanding Postgres's similarity algorithm
Could someone explain how Postgres's similarity algorithm works?
Why do these examples return different results?
select similarity('Foo Bar Baz', 'Foo Bar'); -- 0.8
select similarity('Foo Bar Baz', '...
- 101
5
votes
1
answer
168
views
Match .csv values as INTs. If one value from a group in the .csv matches one in another group, then merge strings
Here we have two sets of numbers. The problem is that I can't figure out how to get from the input to the output of numbers (DDL and DML below and also in the fiddle here).
current_data
1,2,3
1,4
1,5,...
- 67
1
vote
0
answers
74
views
Search by first and last name of the Instructor
I have the below tables in the MySQL database
create table course_class
(
id varchar(36) not null primary key,
class_code varchar(255) not null,
...
- 119
0
votes
1
answer
613
views
string search in table with partial text and without all field names
I use postgresql database and the need is to return all the rows that contain a given string in any column of that table. And string could be like just half . For examaple search string can ve IT ...
- 1
-1
votes
1
answer
90
views
Search string data with special characters removed
We have a table with ~6 million of products:
ID
Name
Code
1
One
123.456.789-M
2
Two
852.789456
3
Three
1-123654.P
What is a good way (with regards to performance) to filter products by code ...
- 191
0
votes
1
answer
439
views
MySQL - Search Alphanumeric string using wildcards - underscore (_) and asterisk (*)
I have a table, products, with a product_id column as follows:
product_id
110177
110177T
177
I am trying to filter down the product results that should fetch result as below but it is also fetching ...
- 103
1
vote
1
answer
298
views
How to do a ranked search based on number of multiple columns matched
Context
I am trying to create a ranked-customer-search that will order results based on "most likely correct". We have several factors we search by, but to keep it simple I will stick with ...
- 111
0
votes
1
answer
101
views
String search is very slow with OR statement
I have the following tables:
product, product_stock, and product_offer
I need to optimize the search when looking for a product that is available in product_stock or that is currently on offer. First, ...
- 127
3
votes
1
answer
137
views
Indexing Referenced Table Columns
I would like to do a search across columns of joined tables. What would the best index configuration be for the query below?
Table A
------------
Id
ValueA
-- Table A has many more columns
Table B
---...
- 275
0
votes
1
answer
98
views
Levenshtein function returning different result based on limit value
The Levenshtein function is not working as I would have expect. Is there anything that I minsunderstood?
Here is the query:
SELECT c0.id, c0.engine_type, c0.mpg, c0.kwh, c0.price, c0.make, c0.model, ...
- 335
3
votes
1
answer
1k
views
Trigram similarity (pg_trgm) with German umlauts
I try to figure out how to improve Postgres 10.6 pg_trgm queries with German umlauts (äöü). In german 'ö' can be written as 'oe'. But beware: not every 'oe' can be written as 'ö'.
CREATE TABLE public....
- 143
1
vote
1
answer
717
views
Perform SELECT using WHERE IN clause on JSON Object in MySQL
I have a json column in MySQL which contains a list of items for eg.
"style": {"style1", "style2", "style3", "style4", "style5"}
I want to ...
- 111
0
votes
0
answers
461
views
Performance of searching for hex strings in large tables (using LIKE, Full-Text Search, etc.)
I have a table with 40+ million rows in MS SQL Server Express 2019. One of the columns store pure hexadecimal strings (both binary and readable ASCII content). I need to search this table for rows ...
- 141
2
votes
0
answers
57
views
Searching across collections based on different column name
I have following collections with fields in my mongodb database:
Collection: Category
[
{
"cat_id": "cat_id_1",
"cat_name": "education"
}...
- 121
0
votes
1
answer
718
views
How to replace (SIMILAR TO + regular expression) with LIKE or ~ in PostgreSQL?
I have the following PostgreSQL function which checks if p_text1 contains the word/phrase p_text2 within it:
CREATE OR REPLACE FUNCTION public."Contains"(
p_text1 character varying,
p_text2 character ...
- 139
1
vote
2
answers
4k
views
Case insensitive LIKE in DB2
Is there a way to do a LIKE operation in DB2 against a varchar column in a case insensitive way, without changing the underlying column definition?
Or is there a workaround like SELECT * FROM mytable ...
- 229
0
votes
3
answers
3k
views
MySQL LIKE IN with Input Parameter of stored procedure Comma Separated Values
I am creating a stored procedure to search user's Towns.
From the User Interface user will select multiple towns that will be sent to the stored procedure.
Sample input of the towns parameter for the ...
0
votes
1
answer
164
views
How to select values consisting of numerals only?
I have a column like this:
WW0476091
YA0457514
547856232
856987452
254785W11
I want to get the values that contain numerals only (decimal digits from 0 to 9). For the example above, I want only ...
6
votes
1
answer
6k
views
Multi language full text search using postgresql
I am trying to implement full text search using postgresql for some images. I am storing some information about my images into a json field in my table. This json has a tags key where I have multiple ...
- 83
0
votes
1
answer
216
views
Like '%' search for value withing longblob column in MySql is slow
MySQL version is 5.7.25
I have table like
CREATE TABLE `applications` (
`id` varchar(25) NOT NULL,
`application` longblob NOT NULL,
PRIMARY KEY (`id`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8;
'...
- 101
3
votes
1
answer
653
views
SQL query with Like operator with Leading Wildcards
I have a query as follows:
select top (30000) * from table1 where licenseplate like '%as43bv%'
I have an index on licenseplate but the query will not hit the index due to leading wildcard.
Since ...
- 1,019
0
votes
1
answer
656
views
How to optimize query for text array in PostgreSQL using `@>` operator
I have a column of type text[] and I want to search over this column using this SQL operator @>
Note: @> operator, it filters the data as such ['a','b'] in ['a','b','c']
The ...
- 159
0
votes
1
answer
926
views
trigram matching on a jsonb array
Hello I'm trying to implement some sort of fuzzy string matching using pg_trgm on my table which contains a jsonb array,
here is a sample data:
name
------------------
[{"firstname": "jhon", "...
- 3
1
vote
2
answers
87
views
Get the matching condition in the SELECT list
Let's say my full text search query is below:
USE AdventureWorks2012;
GO
SELECT Name
FROM Production.Product
WHERE CONTAINS(Name, '"chain*" OR "full*"');
GO
I need one more column that ...
- 2,053
1
vote
1
answer
37
views
Using LOCATE() Function as SUBSTRING() parameter gives ramdom result. Extracting string from text
I have several rows with a lot of content and i'm trying to find some code and extract it. It looks like this:
Some code...
<div> </div>
<div>[flv:http://submarino-libre....
- 27
0
votes
2
answers
93
views
Get matching part from conditional pattern
I'm having a table like this:
|id|key |value |
------------------------
| 0|name |Homer |
| 1|surname|Simpson |
| 2|town |Springfield|
I'm running this query:
SELECT *
FROM ...
- 103
2
votes
2
answers
5k
views
How to find exact string from a sentence
I'm using SQLITE and I'm trying to find the exact word on a sentence, but I'm not getting just the word I'm getting for instance if I'm looking for Water I'm getting also aWater, wateri24 and that's ...
- 123
4
votes
3
answers
14k
views
How to determine if a hyphen (-) exists inside a column
In a CASE expression, I'm trying to search inside a text column to identify a hyphen (-):
CASE
WHEN SUBSTRING(al.ALT_ADDRESS,1,1) IN('1','5','7')
AND al.NEW_ADDRESS CONTAINS '-'
...
- 189
1
vote
0
answers
65
views
Searching for and parsing out specific text parts within the values of a column
I'm working on a CASE expression that I need to have in order to search for, and parse out, specific text values.
Sometimes the relevant column will contain a person's name, and sometimes it will ...
- 189
2
votes
1
answer
3k
views
How to search for a string in all columns of a table?
I use postgresql database and the need is to return all the rows that contain a given string in any column of that table. For example, I have a table like this.
I need a query to return all rows that ...
- 121
-4
votes
1
answer
87
views
which is the appropriate database for my use case [closed]
I have a set of n sentences (n >= 100k).
I want to perform queries of the sort where given a set of n_i sentences i return a set of m_i words that is present in one subset of n_i sentences and not ...
- 1
0
votes
1
answer
627
views
Search for partial matches in website domain names
I have a Postgres database with information about websites and a table called sites with a column host. This already has an index for text pattern operations which is excellent for searching from the ...
- 239
4
votes
1
answer
371
views
T-SQL LIKE Predicate failed to match with whitespace in XML converted varchar
Recently I attempt to search for a particular pattern by converting XML data into varchar(max) although I'm aware it's not the best practice and found out it's not working as expected:-
Setup
...
- 203
0
votes
1
answer
56
views
duplicate entries from mysql LIKE query
with this sample dataset
I have this query
SELECT products.id,
products.title AS product_title,
products.code,
products....
- 33
8
votes
2
answers
1k
views
Fastest way to split/store a long string for charindex function
I have a 1 TB string of digits. Given a 12-character sequence of digits I want to get the start-position of this sequence in the original string (charindex function).
I have tested this with a 1GB ...
- 181
0
votes
1
answer
7k
views
How can I search for a hex string in oracle?
There's a database record that is incorrect. The name field displays like this in a browser ( this is incorrect ):
Thcˇodore
And when I look at the record via SQL results, I see:
Thc\xCB\x87odore
I'...
- 105
1
vote
2
answers
824
views
Query performance of searching pattern
Posted the same question on SO, but did not get answer.
As per Andrey Nikolov comment, tried with Trigram, but the table name and column(more than 50 columns) are dynamic i mean will get from front ...
- 283
4
votes
1
answer
389
views
Find records with same string with extra character
OK, so I have a Microsoft SQL Server 2014 database table called owner with around 90,000 records with owner information, another called vehicle with vehicle information
Owner_Name ...
- 55
0
votes
1
answer
67
views
Which option is better to search in two tables in varchar columns? [duplicate]
I have a performance problem with searching in varchar columns in SQL Server 2016. Considering these tables have plenty of rows, for example 60000 rows each one.
Tables
CREATE TABLE Persons (
...
1
vote
1
answer
283
views
Use extra column to save an unaccented copy of a string instead of using unaccent module [closed]
I am heavily using the unaccent module in a table with 500.000 rows where each row contains proportionally a lot of accented characters.
The issue I am facing is that my queries have become time ...
- 113
2
votes
1
answer
314
views
How to search Query Store for a specific word or command in a query?
I have an Enterprise Edition of SQL 2016 SP1, that has a database with Query Store active.
I want to search for a specific word or command in the saved queries. I have googled around and not seen ...
- 6,178