mirror of
https://github.com/notherealmarco/WASAPhoto.git
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77 lines
2.2 KiB
Go
77 lines
2.2 KiB
Go
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/*
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Package database is the middleware between the app database and the code. All data (de)serialization (save/load) from a
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persistent database are handled here. Database specific logic should never escape this package.
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To use this package you need to apply migrations to the database if needed/wanted, connect to it (using the database
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data source name from config), and then initialize an instance of AppDatabase from the DB connection.
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For example, this code adds a parameter in `webapi` executable for the database data source name (add it to the
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main.WebAPIConfiguration structure):
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DB struct {
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Filename string `conf:""`
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}
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This is an example on how to migrate the DB and connect to it:
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// Start Database
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logger.Println("initializing database support")
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db, err := sql.Open("sqlite3", "./foo.db")
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if err != nil {
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logger.WithError(err).Error("error opening SQLite DB")
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return fmt.Errorf("opening SQLite: %w", err)
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}
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defer func() {
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logger.Debug("database stopping")
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_ = db.Close()
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}()
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Then you can initialize the AppDatabase and pass it to the api package.
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*/
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package database
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import (
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"database/sql"
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"errors"
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"fmt"
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)
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// AppDatabase is the high level interface for the DB
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type AppDatabase interface {
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GetName() (string, error)
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SetName(name string) error
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Ping() error
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}
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type appdbimpl struct {
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c *sql.DB
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}
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// New returns a new instance of AppDatabase based on the SQLite connection `db`.
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// `db` is required - an error will be returned if `db` is `nil`.
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func New(db *sql.DB) (AppDatabase, error) {
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if db == nil {
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return nil, errors.New("database is required when building a AppDatabase")
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}
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// Check if table exists. If not, the database is empty, and we need to create the structure
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var tableName string
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err := db.QueryRow(`SELECT name FROM sqlite_master WHERE type='table' AND name='example_table';`).Scan(&tableName)
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if errors.Is(err, sql.ErrNoRows) {
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sqlStmt := `CREATE TABLE example_table (id INTEGER NOT NULL PRIMARY KEY, name TEXT);`
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_, err = db.Exec(sqlStmt)
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if err != nil {
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return nil, fmt.Errorf("error creating database structure: %w", err)
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}
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}
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return &appdbimpl{
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c: db,
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}, nil
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}
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func (db *appdbimpl) Ping() error {
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return db.c.Ping()
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}
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