File embedding places an external file’s contents in a variable and the compiled binary. Keeping SQL in schema.sql preserves editor highlighting and lets a deployed program run without a separate schema file. section 10.1.3
Embed and apply a database schema
Import embed for its compiler-activation side effect, declare the directive, then pass the resulting string to the database: import ( _ "embed" ) //go:embed schema.sql var schema string func Dial(ctx context.Context, dsn string) (*sql.DB, error) { db, err := sql.Open("sqlite", dsn) if err != nil { return nil, fmt.Errorf("opening: %w", err) } if err := db.PingContext(ctx); err != nil { return nil, fmt.Errorf("pinging: %w", err) } if _, err := db.ExecContext(ctx, schema); err != nil { return nil, fmt.Errorf("applying schema: %w", err) } return db, nil } section 10.1.3
//go:embed *.sql #1
var schemaFiles embed.FS #2
. . .
files, err := schemaFiles.ReadDir(".") #3
. . .
for _, schema := range files { #4
. . . #5
}
Use an embedded embed.FS when a package needs to include multiple matching files, enumerate them, and process each file at runtime. section 10.1.3
Keep the implementation predictable:
- Use a blank embed import when the program only needs the compiler feature, not an exported package symbol. section 10.1.3
- Distribute the compiled binary without additional embedded resource files. section 10.1.3 section 10.6
