gormcol

Type-safe GORM column descriptors and model generation utilities.

Library

The gormcol package provides two approaches for referencing database columns:

Field descriptors

Define struct-like variables mapping Go field names to table.column pairs:

var PsAccess = struct {
    IDProfile           gormcol.Field
    IDAuthorizationRole gormcol.Field
}{
    IDProfile:           gormcol.Field{Table: "ps_access", Column: "id_profile"},
    IDAuthorizationRole: gormcol.Field{Table: "ps_access", Column: "id_authorization_role"},
}

gormcol.Column(PsAccess.IDAuthorizationRole)     // "id_authorization_role"
gormcol.ColumnOnTable(PsAccess.IDAuthorizationRole) // "ps_access.id_authorization_role"
gormcol.TableField(PsAccess.IDAuthorizationRole)  // "ps_access"

Reflection-based utilities

Extract column/table names from GORM struct tags at compile time:

type PsAccess struct {
    IDProfile           uint `gorm:"column:id_profile;primaryKey"`
    IDAuthorizationRole uint `gorm:"column:id_authorization_role"`
}

gormcol.Col[PsAccess]("IDAuthorizationRole")       // "id_authorization_role"
gormcol.Tbl[PsAccess]()                             // "ps_access" (via NamingStrategy)
gormcol.ColOnTbl[PsAccess]("IDAuthorizationRole")  // "ps_access.id_authorization_role"
gormcol.PK[PsAccess]()                              // "id_profile"
gormcol.Columns[PsAccess]()                         // ["id_profile", "id_authorization_role"]
gormcol.ColByJSON[PsAccess]("id_profile")           // "id_profile"

Naming strategy

The reflection-based functions fall back to a configurable NamingStrategy when no explicit gorm:"column:..." tag is set. Default is schema.NamingStrategy{}. Override it with your project's GORM naming strategy:

gormcol.NamingStrategy = db.DB.NamingStrategy

CLI

The cmd/ directory contains a standalone tool that generates GORM model files with column descriptors.

Build

go build -o gormcol-gen ./cmd/

Usage

gormcol-gen --dsn <connection-string> [options]

Flag	Default	Description
`--dsn`	(required)	MySQL/MariaDB DSN, e.g. `user:pass@tcp(localhost:3306)/dbname`
`--filter`	`(ps_\|b2b_).*`	Regex matching table names to generate
`--out`	`./app/model/prestadb`	Output directory for generated files
`--pkg`	`prestadb`	Go package name for generated files

Example

./gormcol-gen --dsn "user:pass@tcp(localhost:3306)/mydb" --filter "ps_.*" --out ./internal/model --pkg model

This connects to the database, generates a .go model file for each matching table, and appends <Model>Cols variables with typed gormcol.Field descriptors to each file.

Dependencies

gorm.io/gorm
gorm.io/gen
gorm.io/driver/mysql

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