MySQL
Edit on GitHubReference for the go-chi-mysql deployment target
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This page documents only how the go-chi-mysql target differs from
go-chi-postgres. Everything not listed here (file
tree, naming conventions, HTTP contract, OpenAPI, the chi app, Dafny
integration, extension points) is identical; read the
PostgreSQL page for the full reference.
The database axis is a pluggable Dialect strategy
(modules/codegen/src/main/scala/specrest/codegen/migration/Dialect.scala) plus
the Go-side GoDbView in EmitGo.scala; together they decide the Bun dialect
and driver, the raw-SQL column types, the connection wiring, and the
docker-compose / generated-CI database service. Selecting MySQL is one flag:
no emitter or template changes.
sbt "cli/run compile --framework chi --db mysql --ignore-verify --out /tmp/out fixtures/spec/url_shortener.spec"Deltas from PostgreSQL
| Aspect | PostgreSQL | MySQL |
|---|---|---|
| Bun dialect | pgdialect | mysqldialect |
| Driver | bun/driver/pgdriver | go-sql-driver/mysql (blank import) |
| App DSN | postgres://…@localhost:5432/…?sslmode=disable | <svc>:<svc>@tcp(localhost:3306)/<svc>?parseTime=true |
golang-migrate URL | postgres://…?sslmode=disable | mysql://<svc>:<svc>@tcp(localhost:3306)/<svc> |
| Database service | postgres:17-alpine in compose / CI | mysql:8.4 in compose / CI |
| Migration tx wrap | BEGIN; … COMMIT; | none (MySQL auto-commits DDL) |
| Unbounded strings | TEXT | VARCHAR(255) |
The emitted docker-compose.yml and .github/workflows/ci.yml provision a
mysql:8.4 service (replacing the Postgres one). internal/database/database.go
opens it with sql.Open("mysql", dsn) (driver registered via the
_ "github.com/go-sql-driver/mysql" blank import) and wraps it in
bun.NewDB(sqldb, mysqldialect.New()).
MySQL implicitly commits DDL, so the emitted migrations/*.sql omit the explicit
BEGIN;/COMMIT; the Postgres target uses.
The column types are String→VARCHAR(255), Int→BIGINT, Float→DOUBLE,
Bool→TINYINT(1), DateTime→DATETIME, Date→DATE, UUID→CHAR(36),
Decimal→DECIMAL, Bytes→LONGBLOB, and Set/Seq→JSON. A 32-bit SERIAL PK
stays INT AUTO_INCREMENT (not widened to BIGINT). The emitter is canonical.
CI gate
.github/workflows/go-build.yml runs the mysql matrix leg: go build plus a
golang-migrate up → down -all → up round-trip against a real mysql:8.4
service, so the emitted migrations/*.sql is proven to apply and reverse on
MySQL.
If this page and the emitted output disagree, the emitter wins; file an issue or PR to correct the doc.