Ignore accents SQLite3 | 易学教程

问题

How do I make a SELECT with a LIKE clause ignoring accents on SQLite3?

PS: It's for Android build-in SQLite support.

回答1:

There has been a similar question here.

They said it is not really possible on Android, but there is a workaround with an additional normalized column.

回答2:

There is a solution, it is not elegant, but it works on Android.

The function REPLACE can replace the accented character by the normal character. Example:

SELECT YOUR_COLUMN FROM YOUR_TABLE WHERE replace(replace(replace(replace(replace(replace(replace(replace(
replace(replace(replace( lower(YOUR_COLUMN), 'á','a'), 'ã','a'), 'â','a'), 'é','e'), 'ê','e'), 'í','i'),
'ó','o') ,'õ','o') ,'ô','o'),'ú','u'), 'ç','c') LIKE 'SEARCH_KEY%'

Or use unicode:

SELECT YOUR_COLUMN FROM YOUR_TABLE WHERE replace(replace(replace(replace(replace(replace(replace(replace(
replace(replace(replace( lower(YOUR_COLUMN), '\u00E1','a'), '\u00E3','a'), '\u00E2','a'), '\u00E9','e'), '\u00EA','e'), '\u00ED','i'),
'\u00F3','o') ,'\u00F5','o') ,'\u00F4' ,'o'),'\u00FA','u'), '\u00E7' ,'c') LIKE 'SEARCH_KEY%'

Where SEARCH_KEY is the key word that you wanna find on the column.

回答3:

You can a create a mask column and update after insert values in to table with a trigger.

-- Table
CREATE TABLE IF NOT EXISTS mytable (
    id TEXT PRIMARY KEY,
    description TEXT default '',
    description_mask TEXT default ''
);

-- Trigger
CREATE TRIGGER IF NOT EXISTS mytable_in AFTER INSERT ON mytable
BEGIN
  UPDATE mytable
  SET description_mask =
  lower(
  replace(replace(replace(replace(replace(replace(replace(replace(replace(replace(replace(replace(
  replace(replace(replace(replace(replace(replace(replace(replace(replace(replace(replace(replace(
  NEW.description,
  'á','a'), 'ã','a'), 'â','a'), 'é','e'), 'ê','e'), 'í','i'), 'ó','o') ,'õ','o') ,'ô','o'),'ú','u'),'ç','c'),'ñ','n'),
  'Á','a'), 'Ã','a'), 'Â','a'), 'É','e'), 'Ê','e'), 'Í','e'), 'Ó','o') ,'Õ','o') ,'Ô','o'),'Ú','u'),'Ç','c'),'Ñ','n')
  )
  WHERE id = NEW.id;
END;

-- Select example
SELECT * FROM mytable WHERE (description LIKE '%acido%' OR description_mask LIKE '%ácido%');

来源：https://stackoverflow.com/questions/5492508/ignore-accents-sqlite3

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