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
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
|
package testfixtures
import (
"database/sql"
"fmt"
)
// PostgreSQL is the PG helper for this package
type PostgreSQL struct {
baseHelper
// UseAlterConstraint If true, the contraint disabling will do
// using ALTER CONTRAINT sintax, only allowed in PG >= 9.4.
// If false, the constraint disabling will use DISABLE TRIGGER ALL,
// which requires SUPERUSER privileges.
UseAlterConstraint bool
tables []string
sequences []string
nonDeferrableConstraints []pgConstraint
}
type pgConstraint struct {
tableName string
constraintName string
}
func (h *PostgreSQL) init(db *sql.DB) error {
var err error
h.tables, err = h.tableNames(db)
if err != nil {
return err
}
h.sequences, err = h.getSequences(db)
if err != nil {
return err
}
h.nonDeferrableConstraints, err = h.getNonDeferrableConstraints(db)
if err != nil {
return err
}
return nil
}
func (*PostgreSQL) paramType() int {
return paramTypeDollar
}
func (*PostgreSQL) databaseName(db *sql.DB) (dbName string) {
db.QueryRow("SELECT current_database()").Scan(&dbName)
return
}
func (h *PostgreSQL) tableNames(db *sql.DB) ([]string, error) {
var tables []string
sql := `
SELECT table_name
FROM information_schema.tables
WHERE table_schema = 'public'
AND table_type = 'BASE TABLE';
`
rows, err := db.Query(sql)
if err != nil {
return nil, err
}
defer rows.Close()
for rows.Next() {
var table string
if err = rows.Scan(&table); err != nil {
return nil, err
}
tables = append(tables, table)
}
return tables, nil
}
func (h *PostgreSQL) getSequences(db *sql.DB) ([]string, error) {
var sequences []string
sql := "SELECT relname FROM pg_class WHERE relkind = 'S'"
rows, err := db.Query(sql)
if err != nil {
return nil, err
}
defer rows.Close()
for rows.Next() {
var sequence string
if err = rows.Scan(&sequence); err != nil {
return nil, err
}
sequences = append(sequences, sequence)
}
return sequences, nil
}
func (*PostgreSQL) getNonDeferrableConstraints(db *sql.DB) ([]pgConstraint, error) {
var constraints []pgConstraint
sql := `
SELECT table_name, constraint_name
FROM information_schema.table_constraints
WHERE constraint_type = 'FOREIGN KEY'
AND is_deferrable = 'NO'
`
rows, err := db.Query(sql)
if err != nil {
return nil, err
}
defer rows.Close()
for rows.Next() {
var constraint pgConstraint
if err = rows.Scan(&constraint.tableName, &constraint.constraintName); err != nil {
return nil, err
}
constraints = append(constraints, constraint)
}
return constraints, nil
}
func (h *PostgreSQL) disableTriggers(db *sql.DB, loadFn loadFunction) error {
defer func() {
// re-enable triggers after load
var sql string
for _, table := range h.tables {
sql += fmt.Sprintf("ALTER TABLE %s ENABLE TRIGGER ALL;", h.quoteKeyword(table))
}
db.Exec(sql)
}()
tx, err := db.Begin()
if err != nil {
return err
}
var sql string
for _, table := range h.tables {
sql += fmt.Sprintf("ALTER TABLE %s DISABLE TRIGGER ALL;", h.quoteKeyword(table))
}
if _, err = tx.Exec(sql); err != nil {
return err
}
if err = loadFn(tx); err != nil {
tx.Rollback()
return err
}
return tx.Commit()
}
func (h *PostgreSQL) makeConstraintsDeferrable(db *sql.DB, loadFn loadFunction) error {
defer func() {
// ensure constraint being not deferrable again after load
var sql string
for _, constraint := range h.nonDeferrableConstraints {
sql += fmt.Sprintf("ALTER TABLE %s ALTER CONSTRAINT %s NOT DEFERRABLE;", h.quoteKeyword(constraint.tableName), h.quoteKeyword(constraint.constraintName))
}
db.Exec(sql)
}()
var sql string
for _, constraint := range h.nonDeferrableConstraints {
sql += fmt.Sprintf("ALTER TABLE %s ALTER CONSTRAINT %s DEFERRABLE;", h.quoteKeyword(constraint.tableName), h.quoteKeyword(constraint.constraintName))
}
if _, err := db.Exec(sql); err != nil {
return err
}
tx, err := db.Begin()
if err != nil {
return err
}
if _, err = tx.Exec("SET CONSTRAINTS ALL DEFERRED"); err != nil {
return err
}
if err = loadFn(tx); err != nil {
tx.Rollback()
return err
}
return tx.Commit()
}
func (h *PostgreSQL) disableReferentialIntegrity(db *sql.DB, loadFn loadFunction) error {
// ensure sequences being reset after load
defer h.resetSequences(db)
if h.UseAlterConstraint {
return h.makeConstraintsDeferrable(db, loadFn)
} else {
return h.disableTriggers(db, loadFn)
}
}
func (h *PostgreSQL) resetSequences(db *sql.DB) error {
for _, sequence := range h.sequences {
_, err := db.Exec(fmt.Sprintf("SELECT SETVAL('%s', %d)", sequence, resetSequencesTo))
if err != nil {
return err
}
}
return nil
}
|
