MySQL

This page documents only how the ts-express-mysql target differs from ts-express-postgres. Everything not listed here — file tree, naming conventions, HTTP contract, OpenAPI, the Express app, Dafny integration, extension points — is identical; read the PostgreSQL page for the full reference.

The database axis is a pluggable Dialect strategy (codegen/migration/Dialect.scala) plus the TS-side TsDbView in EmitTs.scala; together they decide the Prisma provider, the raw-SQL column types in migration.sql, the connection URL, and the docker-compose / generated-CI database service. Selecting MySQL is one flag — no emitter or template changes.

sbt "cli/run compile --framework express --db mysql --ignore-verify --out /tmp/out fixtures/spec/url_shortener.spec"

Deltas from PostgreSQL

Aspect	PostgreSQL	MySQL
Prisma `provider`	`postgresql`	`mysql`
`migration_lock`	`provider = "postgresql"`	`provider = "mysql"`
`DATABASE_URL`	`postgresql://…@localhost:5432/…?schema=public`	`mysql://<svc>:<svc>@localhost:3306/<svc>`
Database service	`postgres:17-alpine` in compose / CI	`mysql:8.4` in compose / CI
Schema native types	`@db.Text`, `@db.Timestamptz()`, …	none (Prisma MySQL defaults)
Unbounded strings	`TEXT`	`VARCHAR(255)`

Compose / CI service. The emitted docker-compose.yml and .github/workflows/ci.yml provision a mysql:8.4 service (replacing the Postgres one).
No native type attributes. The generated schema.prisma models omit the Postgres-only @db.* native types; Prisma's MySQL provider defaults are valid and the actual column types come from the hand-rendered, dialect-aware migration.sql.
Column types. String→VARCHAR(255), Int→BIGINT, Float→DOUBLE, Bool→TINYINT(1), DateTime→DATETIME, Date→DATE, UUID→CHAR(36), Decimal→DECIMAL, Bytes→LONGBLOB. A 32-bit SERIAL PK stays INT AUTO_INCREMENT (not widened to BIGINT). The emitter is canonical.
Surrogate primary key. As on the PostgreSQL target, the synthesized id is Int / number in the Prisma model even though the column is BIGINT AUTO_INCREMENT — a deliberate v0 choice (the JSON bigint story is fragile). prisma generate / tsc / migrate deploy are unaffected; the model↔DB width only needs reconciling under prisma migrate dev / db pull.

CI gate

.github/workflows/ts-build.yml runs the mysql matrix leg: prisma generate, tsc, vitest, build, and a prisma migrate deploy → reset → deploy round-trip against a real mysql:8.4 service.

Prisma ORM 6.15+ adds an AI-agent guardrail that blocks prisma migrate reset (and db push) unless PRISMA_USER_CONSENT_FOR_DANGEROUS_AI_ACTION is set when it detects an AI coding agent. CI is not a detected agent, so the round-trip runs unchanged; the guardrail only affects local runs invoked from an AI agent's shell.

If this page and the emitted output disagree, the emitter wins — file an issue or PR to correct the doc.

Deltas from PostgreSQL

CI gate

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