1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
|
package db
import (
"database/sql"
"embed"
"fmt"
"log"
"path/filepath"
"sort"
"strconv"
"strings"
)
//go:embed migrations/*.sql
var migrationsFS embed.FS
const EXPECTED_SCHEMA_VERSION = 3
type Migration struct {
Version int
Filename string
SQL string
}
func initMigrationTable(db *sql.DB) error {
query := `
CREATE TABLE IF NOT EXISTS schema_migrations (
version INTEGER PRIMARY KEY,
applied_at TEXT NOT NULL DEFAULT CURRENT_TIMESTAMP
);`
_, err := db.Exec(query)
return err
}
func getSchemaVersion(db *sql.DB) (int, error) {
var version int
err := db.QueryRow("SELECT COALESCE(MAX(version), 0) FROM schema_migrations").Scan(&version)
if err != nil {
return 0, err
}
return version, nil
}
func ValidateSchemaVersion(db *sql.DB) error {
currentVersion, err := getSchemaVersion(db)
if err != nil {
return fmt.Errorf("failed to get schema version: %w", err)
}
if currentVersion != EXPECTED_SCHEMA_VERSION {
return fmt.Errorf("schema version mismatch: expected %d, got %d. Run with --migrate to update schema",
EXPECTED_SCHEMA_VERSION, currentVersion)
}
return nil
}
func LoadMigrations() ([]Migration, error) {
entries, err := migrationsFS.ReadDir("migrations")
if err != nil {
return nil, fmt.Errorf("failed to read migrations directory: %w", err)
}
var migrations []Migration
for _, entry := range entries {
if entry.IsDir() || !strings.HasSuffix(entry.Name(), ".sql") {
continue
}
// Parse version from filename (e.g., "001_initial_schema.sql" -> 1)
parts := strings.SplitN(entry.Name(), "_", 2)
if len(parts) < 2 {
continue
}
version, err := strconv.Atoi(parts[0])
if err != nil {
log.Printf("Warning: invalid migration filename %s, skipping", entry.Name())
continue
}
// Read migration SQL
sqlBytes, err := migrationsFS.ReadFile(filepath.Join("migrations", entry.Name()))
if err != nil {
return nil, fmt.Errorf("failed to read migration %s: %w", entry.Name(), err)
}
migrations = append(migrations, Migration{
Version: version,
Filename: entry.Name(),
SQL: string(sqlBytes),
})
}
// Sort migrations by version
sort.Slice(migrations, func(i, j int) bool {
return migrations[i].Version < migrations[j].Version
})
return migrations, nil
}
func RunMigrations(db *sql.DB) error {
// Initialize migration table
if err := initMigrationTable(db); err != nil {
return fmt.Errorf("failed to initialize migration table: %w", err)
}
// Get current version
currentVersion, err := getSchemaVersion(db)
if err != nil {
return fmt.Errorf("failed to get current schema version: %w", err)
}
// Load all migrations
migrations, err := LoadMigrations()
if err != nil {
return fmt.Errorf("failed to load migrations: %w", err)
}
// Find pending migrations
var pendingMigrations []Migration
for _, migration := range migrations {
if migration.Version > currentVersion {
pendingMigrations = append(pendingMigrations, migration)
}
}
if len(pendingMigrations) == 0 {
log.Printf("No pending migrations. Current schema version: %d", currentVersion)
return nil
}
log.Printf("Running %d pending migrations...", len(pendingMigrations))
// Execute each pending migration in a transaction
for _, migration := range pendingMigrations {
log.Printf("Applying migration %d: %s", migration.Version, migration.Filename)
tx, err := db.Begin()
if err != nil {
return fmt.Errorf("failed to start transaction for migration %d: %w", migration.Version, err)
}
// Execute migration SQL
_, err = tx.Exec(migration.SQL)
if err != nil {
tx.Rollback()
return fmt.Errorf("failed to execute migration %d: %w", migration.Version, err)
}
// Record migration as applied
_, err = tx.Exec(
"INSERT INTO schema_migrations (version) VALUES (?)",
migration.Version,
)
if err != nil {
tx.Rollback()
return fmt.Errorf("failed to record migration %d: %w", migration.Version, err)
}
// Commit transaction
if err = tx.Commit(); err != nil {
return fmt.Errorf("failed to commit migration %d: %w", migration.Version, err)
}
log.Printf("Successfully applied migration %d", migration.Version)
}
log.Printf("All migrations completed. Schema version: %d", EXPECTED_SCHEMA_VERSION)
return nil
}
|
