Migration implementation, auto migrate when starting program

This commit is contained in:
Maximilian 2023-02-13 23:41:45 -06:00
parent bbbf14bdc7
commit fcd6477ec3
3 changed files with 135 additions and 1 deletions

105
database/migrate.go Normal file
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@ -0,0 +1,105 @@
package database
import (
"GoWeb/app"
"errors"
"fmt"
"github.com/lib/pq"
"log"
"reflect"
)
// Migrate given a dummy object of any type, it will create a table with the same name as the type and create columns with the same name as the fields of the object
func Migrate(app *app.App, anyStruct interface{}) error {
valueOfStruct := reflect.ValueOf(anyStruct)
typeOfStruct := valueOfStruct.Type()
tableName := typeOfStruct.Name()
err := createTable(app, tableName)
if err != nil {
return err
}
for i := 0; i < valueOfStruct.NumField(); i++ {
fieldType := typeOfStruct.Field(i)
fieldName := fieldType.Name
if fieldName != "Id" && fieldName != "id" {
err := createColumn(app, tableName, fieldName, fieldType.Type.Name())
if err != nil {
return err
}
}
}
return nil
}
// createTable creates a table with the given name if it doesn't exist, it is assumed that id will be the primary key
func createTable(app *app.App, tableName string) error {
sanitizedTableQuery := fmt.Sprintf("CREATE TABLE IF NOT EXISTS \"%s\" (\"Id\" serial primary key)", tableName)
_, err := app.Db.Query(sanitizedTableQuery)
if err != nil {
log.Println("Error creating table: " + tableName)
return err
}
log.Println("Table created successfully (or already exists): " + tableName)
return nil
}
// createColumn creates a column with the given name and type if it doesn't exist
func createColumn(app *app.App, tableName, columnName, columnType string) error {
postgresType, err := getPostgresType(columnType)
if err != nil {
log.Println("Error creating column: " + columnName + " in table: " + tableName + " with type: " + postgresType)
return err
}
sanitizedTableName := pq.QuoteIdentifier(tableName)
query := fmt.Sprintf("ALTER TABLE %s ADD COLUMN IF NOT EXISTS \"%s\" %s", sanitizedTableName, columnName, postgresType)
_, err = app.Db.Query(query)
if err != nil {
log.Println("Error creating column: " + columnName + " in table: " + tableName + " with type: " + postgresType)
return err
}
log.Println("Column created successfully (or already exists):", columnName)
return nil
}
// Given a type in Go, return the corresponding type in Postgres
func getPostgresType(goType string) (string, error) {
switch goType {
case "int":
case "int32":
case "uint":
case "uint32":
return "integer", nil
case "int64":
case "uint64":
return "bigint", nil
case "int16":
case "int8":
case "uint16":
case "uint8":
case "byte":
return "smallint", nil
case "string":
return "text", nil
case "float64":
return "double precision", nil
case "bool":
return "boolean", nil
case "time.Time":
return "timestamp", nil
case "[]byte":
return "bytea", nil
default:
return "text", nil
}
return "", errors.New("Unknown type: " + goType)
}

10
main.go
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@ -4,6 +4,7 @@ import (
"GoWeb/app"
"GoWeb/config"
"GoWeb/database"
"GoWeb/models"
"GoWeb/routes"
"embed"
"log"
@ -37,8 +38,15 @@ func main() {
file, err := os.OpenFile("logs/"+time.Now().Format("2006-01-02")+".log", os.O_CREATE|os.O_WRONLY|os.O_APPEND, 0666)
log.SetOutput(file)
// Connect to database
// Connect to database and run migrations
appLoaded.Db = database.ConnectDB(&appLoaded)
if appLoaded.Config.Db.AutoMigrate {
err = models.RunAllMigrations(&appLoaded)
if err != nil {
log.Println(err)
return
}
}
// Define Routes
routes.GetRoutes(&appLoaded)

21
models/migrations.go Normal file
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@ -0,0 +1,21 @@
package models
import (
"GoWeb/app"
"GoWeb/database"
)
// RunAllMigrations defines the structs that should be represented in the database
func RunAllMigrations(app *app.App) error {
// Declare new dummy user for reflection
user := User{
Id: 1, // Id is handled automatically, but it is added here to show it will be skipped during column creation
Username: "migrate",
Password: "migrate",
AuthToken: "migrate",
CreatedAt: "2021-01-01 00:00:00",
UpdatedAt: "2021-01-01 00:00:00",
}
return database.Migrate(app, user)
}