mybatis-sql-standard

Layer 3 (Persistence). TRIGGER when touching mapper XML, SQL fragment, or table schema. Daily decisions without opening SKILL.md: - NO JOIN to fetch dictionary/redundant fields — single-table query + in-memory assembly (95% of queries are single-table). - NO ${} parameter substitution (SQL injection); use #{} or a whitelisted enum. - NO SELECT * — list columns; skip large TEXT/JSON unless explicitly needed. - NO physical foreign keys; store ids logically and rely on application-level boundaries. - Every business table has the 8 standard audit columns (id, tenant_id, create_time, update_time, create_by, update_by, is_deleted, version). - Prefer LambdaQueryWrapper over hardcoded XML for single-table queries. - Don't add tenant_id = #{} manually — the global TenantLineInnerInterceptor injects it. - Type-match params to columns (VARCHAR↔String, BIGINT↔Long); type mismatch disables the index. Open SKILL.md when deciding: composite index leftmost-prefix design, IN-clause partitioning threshold, <choose>/<if> patterns for safe dynamic sorting.