<skill_overview> <purpose>Write safe, validated, and efficient SQLx queries</purpose> <triggers> <trigger>Writing SQL queries with SQLx</trigger> <trigger>Using compile-time query macros</trigger> <trigger>Optimizing database access patterns</trigger> <trigger>Working with transactions</trigger> </triggers> <sources> <source url="https://github.com/launchbadge/sqlx">SQLx GitHub</source> </sources> </skill_overview> <query_rules> <rule name="prefer_query_macros" priority="high"> <description>Use query! or query_as! for compile-time validation</description> </rule> <rule name="bind_params" priority="critical"> <description>Always bind parameters, never concatenate user input</description> </rule> <rule name="fetch_methods" priority="medium"> <description>Use fetch_one, fetch_optional, fetch_all appropriately</description> </rule> <example> <code> let rec = sqlx::query!("SELECT id FROM users WHERE email = $1", email) .fetch_optional(&pool) .await?; </code> </example> </query_rules> <compile_time_checks> <rules> <rule>Ensure DATABASE_URL is available at build time</rule> <rule>Use sqlx prepare and SQLX_OFFLINE for offline builds</rule> </rules> </compile_time_checks> <transactions> <rules> <rule>Wrap multi-step changes in a transaction</rule> <rule>Pass &mut Transaction to query calls</rule> </rules> <example> <code> let mut tx = pool.begin().await?; sqlx::query!("DELETE FROM items WHERE id = $1", id) .execute(&mut tx) .await?; tx.commit().await?; </code> </example> </transactions> <performance> <rules> <rule>Batch queries instead of querying in loops</rule> <rule>Prefer streaming fetch for large result sets</rule> </rules> </performance> <anti_patterns> <avoid name="string_concat_sql">Never build SQL via string concatenation</avoid> <avoid name="pool_per_request">Do not create a new pool per request</avoid> <avoid name="n_plus_one">Avoid running queries inside loops</avoid> </anti_patterns>