Check if column string in database is a substring of a query in sqlite

问题

the current Sqlite syntax can check if a query is a substring of a column string. and I can do a hack to add a % behind the ? described in https://stackoverflow.com/a/5752671/908821

final String whereClause = DbHelper.COLUMN_URL + " LIKE ? " ;

is there a syntax where i can do the opposite? I want to check if the column string is a substring of a query.

The following code does not seem to work.

final String whereClause = "? LIKE "  +  DbHelper.COLUMN_URL ;

The following are the rest of my codes:

String[] whereArg = {url};

ContentValues values = new ContentValues();
values.put(DbHelper.COLUMN_LAST_URL, lastUrl);

database.updateWithOnConflict(DbHelper.TABLE_BOOKMARK,
                values,
                whereClause,
                whereArg,
                SQLiteDatabase.CONFLICT_IGNORE);

I am trying to update "LastUrl" column if the base url is a subString of a query.

some examples that i like to catch

Base Url (in database)         Query
-----------------------------------------------------------------
http://example.com/path        http://example.com/path/path2
http://example.com/path?id=0   http://example.com/path?id=0&x=xx

回答1:

The LIKE operator checks whether the value on the left matches the pattern on the right. So just put the value on the left, and the pattern on the right. If the pattern needs a % that is not in the database, you have to append it:

SELECT ... WHERE ? LIKE LastUrl || '%' ...

来源：https://stackoverflow.com/questions/46420246/check-if-column-string-in-database-is-a-substring-of-a-query-in-sqlite

标签

android

sqlite

android-sqlite