sequelize/sequelize

Issue For the mssql dialect, every JS string value is escaped/bound as Unicode (N'...' literals, and TYPES.NVarChar for bound parameters), regardless of the actual column's SQL type. This happens unconditionally, with no way to opt out per-model or per-column. This causes a well-known SQL Server performance problem: when a VARCHAR column is compared against an NVARCHAR literal/parameter, SQL Server must implicitly convert the column (not just the parameter) to match type precedence rules. That conversion is applied per-row, which prevents the query optimizer from using an index seek on that column — it falls back to a full index/table scan. See Microsoft's own guidance on this: "Implicit conversion may affect cardinality estimates in the query plan". Many production schemas — including ours, and presumably many others migrated from older systems or designed for ASCII-only data (codes, IDs, statuses) — use plain VARCHAR columns. For these, Sequelize's default behavior silently cau

Issue Creation Checklist I understand that my issue will be automatically closed if I don't fill in the requested information I have read the contribution guidelines Feature Description Describe the feature you'd like to see implemented Add native support for generating UUIDv7 values without requiring the external uuid npm package. Node.js has native crypto.randomUUID() for v4-style UUIDs, and native UUIDv7 generation is landing in newer Node versions (see nodejs/node#62529). PostgreSQL has also added native UUIDv7 generation support. Example of the proposed usage: ```ts @Attribute(DataTypes.UUID) @PrimaryKey @default(fn('uuidv7')) declare id: CreationOptional; ``` This would let users generate time-ordered, sortable UUIDs as primary keys directly through Sequelize's fn() helper, similar to how UUIDV4 is currently supported. Describe why you would like this feature to be added to Sequelize Sequelize currently depends on the external uuid package for UUID generation, which has cause