4 ms·

Fascinating since I found the recent Claude models untrustworthy for writing and editing SQL. E.g. it'd write conditions correctly, but not add parens around AN

by baq 1y ago

Fascinating since I found the recent Claude models untrustworthy for writing and editing SQL. E.g. it'd write conditions correctly, but not add parens around ANDs and ORs (which gemini pro then highlighted as a bug, correctly.)

risyachka 1y ago
I bet it highly depends on the work you do. It is very useful for simpler tasks like writing tests, converting code bases etc where the hard part is already done. When it comes to actually doing something hard - it is not very useful at least in my experience. And if you do something even a bit niche - it is mostly useless and its faster do dig into topic on your own that try to have Claude implement it.
- danielbln 1y ago
  Even when I hand roll certain things, it still nice to have Claude Code take over any other grunt work that might come my way. And there are always yaks to shave, always.
CharlesW 1y ago
If you aren't already (1) telling Claude Code which flavor of SQL you want (there are several major dialects and many more minor ones) and (2) giving it access to up-to-date documentation via MCP (e.g. https://github.com/arabold/docs-mcp-server https://github.com/arabold/docs-mcp-server) so it has direct access to canonical docs for authoritative grounding and syntax references, you'll find that you get much better results by doing one or both of those things.
- impure-aqua 1y ago
  Documentation on features your SQL dialect supports and key requirements for your query are very important for incentivizing it to generate the output you want. As a recent example, I am working on a Rust app with integrated DuckDB, and asked it to implement a scoring algorithm query (after chatting with it to generate a Markdown file "RFC" describing how the algorithm works.) It started the implementation with an absolute minimal SQL query that pulled all metrics for a given time window. I questioned this rather than accepting the change, and it said its plan was to implement the more complex aggregation logic in Rust because 1) it's easier to interpret Rust branching logic than SQL statements (true) and 2) because not all SQL dialects include EXP(), STDDEV(), VAR() support which would be necessary to compute the metrics. The former point actually seems like quite a reasonable bias to me, personally I find it harder to review complex aggregations in SQL than mentally traversing the path of data through a bunch of branches. But if you are familiar with DuckDB you know that 1) it does support these features and 2) the OLAP efficiency of DuckDB makes it a better choice for doing these aggregations in a performant way than iterating through the results in Rust, so the initial generated output is suboptimal. I informed it of DuckDB's support for these operations and pointed out the performance consideration and it gladly generated the (long and certainly harder to interpret) SQL query, so it is clearly quite capable, just needs some prodding to go in the right direction.
- msikora 1y ago
  Haven't heard of docs-mcp-server, but there is the very popular Context7 with 23k Github stars and more active development: https://github.com/upstash/context7 https://github.com/upstash/context7
  - CharlesW 1y ago
    Great suggestion, thank you!
UltraSane 1y ago
Claude Sonnet 4 is very good at generating Cypher queries for Neo4j
globalise83 1y ago
Try getting Claude to write a style guideline based on some of your existing manually coded work and then see if it improves using that in context.
ako 1y ago
I found claude sonnet 4 really good at writing SQL if you give it a feedback loop with real data. It will research the problem, research the data, and improve queries until it finds a solution. And then it will optimize it, even optimize performance if you ask it to run explain plan or look at pg_stat_statemnts (postgres).
- martinald 1y ago
  It's outrageously good at performance optimization. There's been multiple really complex queries I've optimized with it that I'd been putting off for a long time. Claude code figured the exact indexes to add within seconds (not ones I would have got easily manually).
nojito 1y ago
The trick is to have it run it through sqlglot and correct the errors.
- yakz 1y ago
  This kind of thing is a key point. Tell Claude Code to build the project, run linters, run the tests, and fix the errors. This (in my experience) has a good chance of filtering out mistakes. Claude is fully capable of running all of the tools, reading the output, and iterating. Higher level mistakes will need code written in a way that is testable with tests that can catch them, although you probably want that anyway.

by baq 1y ago

risyachka 1y ago

I bet it highly depends on the work you do. It is very useful for simpler tasks like writing tests, converting code bases etc where the hard part is already done. When it comes to actually doing something hard - it is not very useful at least in my experience. And if you do something even a bit niche - it is mostly useless and its faster do dig into topic on your own that try to have Claude implement it.

danielbln 1y ago
Even when I hand roll certain things, it still nice to have Claude Code take over any other grunt work that might come my way. And there are always yaks to shave, always.

CharlesW 1y ago

If you aren't already (1) telling Claude Code which flavor of SQL you want (there are several major dialects and many more minor ones) and (2) giving it access to up-to-date documentation via MCP (e.g. https://github.com/arabold/docs-mcp-server https://github.com/arabold/docs-mcp-server) so it has direct access to canonical docs for authoritative grounding and syntax references, you'll find that you get much better results by doing one or both of those things.

impure-aqua 1y ago
Documentation on features your SQL dialect supports and key requirements for your query are very important for incentivizing it to generate the output you want. As a recent example, I am working on a Rust app with integrated DuckDB, and asked it to implement a scoring algorithm query (after chatting with it to generate a Markdown file "RFC" describing how the algorithm works.) It started the implementation with an absolute minimal SQL query that pulled all metrics for a given time window. I questioned this rather than accepting the change, and it said its plan was to implement the more complex aggregation logic in Rust because 1) it's easier to interpret Rust branching logic than SQL statements (true) and 2) because not all SQL dialects include EXP(), STDDEV(), VAR() support which would be necessary to compute the metrics. The former point actually seems like quite a reasonable bias to me, personally I find it harder to review complex aggregations in SQL than mentally traversing the path of data through a bunch of branches. But if you are familiar with DuckDB you know that 1) it does support these features and 2) the OLAP efficiency of DuckDB makes it a better choice for doing these aggregations in a performant way than iterating through the results in Rust, so the initial generated output is suboptimal. I informed it of DuckDB's support for these operations and pointed out the performance consideration and it gladly generated the (long and certainly harder to interpret) SQL query, so it is clearly quite capable, just needs some prodding to go in the right direction.
msikora 1y ago
Haven't heard of docs-mcp-server, but there is the very popular Context7 with 23k Github stars and more active development: https://github.com/upstash/context7 https://github.com/upstash/context7
- CharlesW 1y ago
  Great suggestion, thank you!

UltraSane 1y ago

Claude Sonnet 4 is very good at generating Cypher queries for Neo4j

globalise83 1y ago

Try getting Claude to write a style guideline based on some of your existing manually coded work and then see if it improves using that in context.

ako 1y ago

I found claude sonnet 4 really good at writing SQL if you give it a feedback loop with real data. It will research the problem, research the data, and improve queries until it finds a solution. And then it will optimize it, even optimize performance if you ask it to run explain plan or look at pg_stat_statemnts (postgres).

martinald 1y ago
It's outrageously good at performance optimization. There's been multiple really complex queries I've optimized with it that I'd been putting off for a long time. Claude code figured the exact indexes to add within seconds (not ones I would have got easily manually).

nojito 1y ago

The trick is to have it run it through sqlglot and correct the errors.

yakz 1y ago
This kind of thing is a key point. Tell Claude Code to build the project, run linters, run the tests, and fix the errors. This (in my experience) has a good chance of filtering out mistakes. Claude is fully capable of running all of the tools, reading the output, and iterating. Higher level mistakes will need code written in a way that is testable with tests that can catch them, although you probably want that anyway.