forked from gemnasium/migrate
-
Notifications
You must be signed in to change notification settings - Fork 0
/
postgres.go
158 lines (138 loc) · 3.63 KB
/
postgres.go
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
// Package postgres implements the Driver interface.
package postgres
import (
"database/sql"
"errors"
"fmt"
"strconv"
"github.com/gemnasium/migrate/driver"
"github.com/gemnasium/migrate/file"
"github.com/gemnasium/migrate/migrate/direction"
"github.com/lib/pq"
)
type Driver struct {
db *sql.DB
}
const tableName = "schema_migrations"
func (driver *Driver) Initialize(url string) error {
db, err := sql.Open("postgres", url)
if err != nil {
return err
}
if err := db.Ping(); err != nil {
return err
}
driver.db = db
if err := driver.ensureVersionTableExists(); err != nil {
return err
}
return nil
}
func (driver *Driver) Close() error {
if err := driver.db.Close(); err != nil {
return err
}
return nil
}
func (driver *Driver) ensureVersionTableExists() error {
if _, err := driver.db.Exec("CREATE TABLE IF NOT EXISTS " + tableName + " (version bigint not null primary key);"); err != nil {
return err
}
r := driver.db.QueryRow("SELECT data_type FROM information_schema.columns where table_name = $1 and column_name = 'version'", tableName)
dataType := ""
if err := r.Scan(&dataType); err != nil {
return err
}
if dataType != "integer" {
return nil
}
_, err := driver.db.Exec("ALTER TABLE " + tableName + " ALTER COLUMN version TYPE bigint")
return err
}
func (driver *Driver) FilenameExtension() string {
return "sql"
}
func (driver *Driver) Migrate(f file.File, pipe chan interface{}) {
defer close(pipe)
pipe <- f
tx, err := driver.db.Begin()
if err != nil {
pipe <- err
return
}
if f.Direction == direction.Up {
if _, err := tx.Exec("INSERT INTO "+tableName+" (version) VALUES ($1)", f.Version); err != nil {
pipe <- err
if err := tx.Rollback(); err != nil {
pipe <- err
}
return
}
} else if f.Direction == direction.Down {
if _, err := tx.Exec("DELETE FROM "+tableName+" WHERE version=$1", f.Version); err != nil {
pipe <- err
if err := tx.Rollback(); err != nil {
pipe <- err
}
return
}
}
if err := f.ReadContent(); err != nil {
pipe <- err
return
}
if _, err := tx.Exec(string(f.Content)); err != nil {
pqErr := err.(*pq.Error)
offset, err := strconv.Atoi(pqErr.Position)
if err == nil && offset >= 0 {
lineNo, columnNo := file.LineColumnFromOffset(f.Content, offset-1)
errorPart := file.LinesBeforeAndAfter(f.Content, lineNo, 5, 5, true)
pipe <- errors.New(fmt.Sprintf("%s %v: %s in line %v, column %v:\n\n%s", pqErr.Severity, pqErr.Code, pqErr.Message, lineNo, columnNo, string(errorPart)))
} else {
pipe <- errors.New(fmt.Sprintf("%s %v: %s", pqErr.Severity, pqErr.Code, pqErr.Message))
}
if err := tx.Rollback(); err != nil {
pipe <- err
}
return
}
if err := tx.Commit(); err != nil {
pipe <- err
return
}
}
// Version returns the current migration version.
func (driver *Driver) Version() (file.Version, error) {
var version file.Version
err := driver.db.QueryRow("SELECT version FROM " + tableName + " ORDER BY version DESC LIMIT 1").Scan(&version)
switch {
case err == sql.ErrNoRows:
return 0, nil
case err != nil:
return 0, err
default:
return version, nil
}
}
// Versions returns the list of applied migrations.
func (driver *Driver) Versions() (file.Versions, error) {
versions := file.Versions{}
rows, err := driver.db.Query("SELECT version FROM " + tableName + " ORDER BY version DESC")
if err != nil {
return versions, err
}
defer rows.Close()
for rows.Next() {
var version file.Version
err := rows.Scan(&version)
if err != nil {
return versions, err
}
versions = append(versions, version)
}
err = rows.Err()
return versions, err
}
func init() {
driver.RegisterDriver("postgres", &Driver{})
}