migrate

Documentation

Overview

ddl.go generates dialect-specific DDL SQL from a migration changeset.

Package migrate implements the `gco migrate` commands for database migration management.

planner.go implements the schema diff engine that compares two IR schemas and produces a structured changeset describing the migration steps.

Index

• func CreateMigrationsTable(dialect string) string
• func Run(args []string) error
• type Change
• type ChangeRecord
• type ChangeType
• type Changeset
  • func Diff(old, new *ir.Schema) *Changeset
• type DDLGenerator
  • func (g DDLGenerator) GenerateDown(cs *Changeset) string
  • func (g DDLGenerator) GenerateUp(cs *Changeset) string
• type MigrationManifest
• type MigrationRecord
• type RollbackSafety

Functions

func CreateMigrationsTable

func CreateMigrationsTable(dialect string) string

CreateMigrationsTable returns the SQL to create the migrations metadata table.

func Run

func Run(args []string) error

Run executes the migrate subcommand.

Types

type Change

type Change struct {
	Type     ChangeType
	Model    string            // Table/model name.
	Field    string            // Column name (if applicable).
	OldValue string            // Previous value (for renames, type changes).
	NewValue string            // New value.
	Details  map[string]string // Additional context.
	Rollback RollbackSafety
}

Change represents a single schema change.

type ChangeRecord

type ChangeRecord struct {
	Type     string `json:"type"`
	Model    string `json:"model"`
	Field    string `json:"field,omitempty"`
	Rollback string `json:"rollback"`
}

ChangeRecord stores a single schema change in the migration manifest.

type ChangeType

type ChangeType string

ChangeType categorizes a schema change.

const (
	CreateTable  ChangeType = "CreateTable"
	DropTable    ChangeType = "DropTable"
	RenameTable  ChangeType = "RenameTable"
	AddColumn    ChangeType = "AddColumn"
	DropColumn   ChangeType = "DropColumn"
	RenameColumn ChangeType = "RenameColumn"
	AlterType    ChangeType = "AlterType"
	AlterNull    ChangeType = "AlterNullability"
	AlterDefault ChangeType = "AlterDefault"
	AddIndex     ChangeType = "AddIndex"
	DropIndex    ChangeType = "DropIndex"
	AddUnique    ChangeType = "AddUnique"
	DropUnique   ChangeType = "DropUnique"
	ChangePK     ChangeType = "ChangePrimaryKey"
	AddFK        ChangeType = "AddForeignKey"
	DropFK       ChangeType = "DropForeignKey"
)

type Changeset

type Changeset struct {
	Changes []Change
	Old     *ir.Schema // Source schema (may be nil for initial migration).
	New     *ir.Schema // Target schema (may be nil for teardown).
}

Changeset is an ordered list of changes from old to new schema.

func Diff

func Diff(old, new *ir.Schema) *Changeset

Diff compares two schemas and returns the changes needed to go from old to new.

type DDLGenerator

type DDLGenerator struct {
	Dialect string     // "postgresql", "mysql", "sqlite"
	Schema  *ir.Schema // Target schema for type lookups.
}

DDLGenerator generates dialect-specific DDL from a changeset.

func (DDLGenerator) GenerateDown

func (g DDLGenerator) GenerateDown(cs *Changeset) string

GenerateDown produces the best-effort down migration SQL.

func (DDLGenerator) GenerateUp

func (g DDLGenerator) GenerateUp(cs *Changeset) string

GenerateUp produces the up migration SQL.

type MigrationManifest

type MigrationManifest struct {
	ID             string         `json:"id"`
	Description    string         `json:"description"`
	Checksum       string         `json:"checksum"`
	CreatedAt      time.Time      `json:"createdAt"`
	ToolVersion    string         `json:"toolVersion"`
	DestructiveOps []string       `json:"destructiveOps,omitempty"`
	ReviewRequired bool           `json:"reviewRequired"`
	Changes        []ChangeRecord `json:"changes,omitempty"`
	Models         []string       `json:"models,omitempty"`
}

MigrationManifest describes a single migration.

type MigrationRecord

type MigrationRecord struct {
	ID              string `json:"id"`
	Checksum        string `json:"checksum"`
	AppliedAt       string `json:"appliedAt"`
	ExecutionTimeMs int64  `json:"executionTimeMs"`
	Status          string `json:"status"` // "applied", "failed", "rolled_back"
	ToolVersion     string `json:"toolVersion"`
}

MigrationRecord tracks an applied migration in the database.

type RollbackSafety

type RollbackSafety string

RollbackSafety indicates how safe it is to reverse a change.

const (
	SafeRollback        RollbackSafety = "safe"
	DestructiveRollback RollbackSafety = "destructive"
	ReviewRequired      RollbackSafety = "review"
)