-
Notifications
You must be signed in to change notification settings - Fork 1
/
dbFacet.go
210 lines (190 loc) · 5.38 KB
/
dbFacet.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
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
// Copyright (c) 2016 OpenM++
// This code is licensed under the MIT license (see LICENSE.txt for details)
package db
import (
"database/sql"
"strconv"
"strings"
)
// Facet is type to define database provider and driver facets, ie: name of bigint type
type Facet uint8
// maxTableNameSize return max length of db table or view name.
// Current max name sizes: PostgreSQL=63 MySQL=64 MSSQL=128 DB2=128 Oracle=128 (Oracle antiques not supported)
const maxTableNameSize int = 63
const (
DefaultFacet Facet = iota // common default db facet
SqliteFacet // SQLite db facet
PgSqlFacet // PostgreSQL db facet
MySqlFacet // MySQL and MariaDB facet
MsSqlFacet // MS SQL db facet
OracleFacet // Oracle db facet
Db2Facet // DB2 db facet
)
// String is default printable value of db facet, Stringer implementation
func (facet Facet) String() string {
switch facet {
case DefaultFacet:
return "Default db facet"
case SqliteFacet:
return "Sqlite db facet"
case PgSqlFacet:
return "PostgreSQL db facet"
case MySqlFacet:
return "MySQL db facet"
case MsSqlFacet:
return "MS SQL db facet"
case OracleFacet:
return "Oracle db facet"
case Db2Facet:
return "DB2 db facet"
}
return "Unknown db facet"
}
// bigintType return type name for BIGINT sql type
func (facet Facet) bigintType() string {
if facet == OracleFacet {
return "NUMBER(19)"
}
return "BIGINT"
}
// floatType return type name for FLOAT standard sql type
func (facet Facet) floatType() string {
if facet == OracleFacet {
return "BINARY_DOUBLE"
}
return "FLOAT"
}
// textType return column type DDL for long VARCHAR columns, use it for len > 255.
func (facet Facet) textType(len int) string {
switch facet {
case MsSqlFacet:
if len > 4000 {
return "TEXT"
}
case OracleFacet:
if len > 2000 {
return "CLOB"
}
}
return "VARCHAR(" + strconv.Itoa(len) + ")"
}
// createTableIfNotExist return sql statement to create table if not exists
func (facet Facet) createTableIfNotExist(tableName string, bodySql string) string {
switch facet {
case SqliteFacet, PgSqlFacet, MySqlFacet:
return "CREATE TABLE IF NOT EXISTS " + tableName + " " + bodySql
case MsSqlFacet:
return "IF NOT EXISTS" +
" (SELECT * FROM INFORMATION_SCHEMA.TABLES T WHERE T.TABLE_NAME = " + toQuoted(tableName) + ") " +
" CREATE TABLE " + tableName + " " + bodySql
}
return "CREATE TABLE " + tableName + " " + bodySql
}
// createViewIfNotExist return sql statement to create view if not exists
func (facet Facet) createViewIfNotExist(viewName string, bodySql string) string {
switch facet {
case SqliteFacet:
return "CREATE VIEW IF NOT EXISTS " + viewName + " AS " + bodySql
case PgSqlFacet, MySqlFacet:
return "CREATE OR REPLACE VIEW " + viewName + " AS " + bodySql
case MsSqlFacet:
return "CREATE VIEW " + viewName + " AS " + bodySql
case OracleFacet, Db2Facet:
return "CREATE OR REPLACE VIEW " + viewName + " AS " + bodySql
}
return "CREATE VIEW " + viewName + " AS " + bodySql
}
// detectFacet obtains db facet by quiering sql server.
// It may not be always reliable and even not true facet.
// It is better to use driver information to determine db facet.
func detectFacet(dbConn *sql.DB) Facet {
facet := DefaultFacet
// check is it PostgreSQL
// check is it MySQL (not reliable) or MariaDB
// odbc driver bug (?): PostgreSQL 9.2 + odbc 9.5.400 fails forever after first query failed
// that means PostgreSQL facet detection must be first
_ = SelectRows(dbConn,
"SELECT LOWER(VERSION())",
func(rows *sql.Rows) error {
var s sql.NullString
if err := rows.Scan(&s); err != nil {
return err
}
if s.Valid {
v := s.String
if strings.Contains(v, "postgresql") {
facet = PgSqlFacet
}
if facet == DefaultFacet &&
(strings.Contains(v, "mysql") || strings.Contains(v, "mariadb") || strings.HasPrefix(v, "5.")) {
facet = MySqlFacet
}
}
return nil
})
if facet != DefaultFacet {
return facet
}
// check is it SQLite
_ = SelectRows(dbConn,
"SELECT COUNT(*) FROM sqlite_master",
func(rows *sql.Rows) error {
var n sql.NullInt64
if err := rows.Scan(&n); err != nil {
return err
}
if n.Valid {
facet = SqliteFacet
}
return nil
})
if facet != DefaultFacet {
return facet
}
// check is it MS SQL
_ = SelectRows(dbConn,
"SELECT LOWER(@@VERSION)",
func(rows *sql.Rows) error {
var s sql.NullString
if err := rows.Scan(&s); err != nil {
return err
}
if s.Valid {
facet = MsSqlFacet
}
return nil
})
if facet != DefaultFacet {
return facet
}
// check is it Oracle
_ = SelectRows(dbConn,
"SELECT LOWER(product) FROM product_component_version",
func(rows *sql.Rows) error {
var s sql.NullString
if err := rows.Scan(&s); err != nil {
return err
}
if s.Valid {
facet = OracleFacet
}
return nil
})
if facet != DefaultFacet {
return facet
}
// check is it IBM DB2
_ = SelectRows(dbConn,
"SELECT COUNT(*) FROM SYSIBMADM.ENV_PROD_INFO",
func(rows *sql.Rows) error {
var n sql.NullInt64
if err := rows.Scan(&n); err != nil {
return err
}
if n.Valid {
facet = Db2Facet
}
return nil
})
return facet
}