Sqlite json example8/2/2023 ![]() ![]() Ideally if there is an even simpler way to query this then that would be much appreciated. I still have not been able to find the right way to query this efficiently and am looking for any suggestions. This case however fails in most other cases for example where I search, it returns both the entities in this case but it should return none. I want to know as to why it works in the case above? The only thing that I can think of is that it checks each value of the array to be either tag1 or tag2 but I don't understand why it returns Entity 1 which also has a value of tag3 and does not match the criteria. WHERE json_each.value IS "tag1" OR "tag2" Is this valid or is there another explanation?Ī query that did work for me in the very specific use case of checking values and returning only Entity 1 is SELECT * As to why it fails, I think that it tries to match each value of the array to be tag1 and tag2 which is not the case as each element has only 1 value. The query I expected to work was SELECT *īut this query fails all the cases. If my input is then I want to return only Entity 1 whereas if my input is tag2 then I want to return both the entities. In this example I want to query for tags that match multiple values. This makes the code a whole lot eaiser to understand and to maintain.I am trying to use the json1 extension to query my sqlite database and want to query a json array to match multiple values and return the entry that matches all the values. to store intermediate results and write a sequence of SQL statements instead. Unlike other RDBMS, SQLite doesn't allow you to add, modify or delete columns in a table after a table is created. We may be forced to change the schema of that SQLite database. Consider using SQLite in memory tables - CREATE TEMP TABLE. 1 08-21-2018 03:17 PM by StephenQuan1 Esri Contributor Summary Consider a project which uses a SQLite database. It usually comes inbuilt for mobile phones, computers, and. This database engine is used throughout the world for various applications and devices. It is easy to waste your time writing extremely convoluted and hard to maintain SQL in an effort to perform in-place JSON manipulation. SQLite is a C-language software library that is open-sourced and built to run a full-featured, fast, reliable, serverless, zero-configuration, self-contained SQL database engine. Having now worked with JSON1 in SQLite for a while I have a tip to share with others going down the same road. The WHERE id = bits ensure that we target the right row. ![]() If the relevant value does not exsit in the first place we do not want to do a + 1 on a null value so we do an IFNULL TEST.The SELECT json_set part is where we establish the value to be updated.The UPDATE keywords part does the actual updating, but it needs to know what to updatte.Given how complicated this looks a few explanations are in order Will accomplish both of the updates I have described in my original question above. (select json_extract(keywords.locs,'$.**N**') from keywords where id = '1'), What I have set out to do here is possible but the SQL syntax is rather more convoluted. I could have just deleted this question but given that the SQLite JSON1 extension appears to be relatively poorly understood I felt it would be more useful to provide an answer here for the benefit of others. I'd be most obliged to anyone who might be able to tell me how/whether this should/can be done. Which gave the error message error near json_set. I tried something along the lines of UPDATE keywords json_set(locs,'$.2','2') WHERE kwd = 'stackoverflow' SQlite JSON support to the rescue As mentioned in the intro of the article, SQlite has built-in support to query columns that contain JSON documents (support was added in SQlite 3.9) through the JSON1 extension. It is not clear to me that this can in fact be done. A sample entry in this database table would be like the one shown below id:1,lang:1,kwd:'stackoverflow',locs:'' I am using this table to store keyword searches and recording the locations from which the search was ininitated in the object locs. However, I have not been able to figure out how I can update or insert individual JSON attribute values. The SQLite JSON1 extension has some really neat capabilities.
0 Comments
Leave a Reply.AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |