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
|
require "sqlite3"
module Guff
class Database < ::SQLite3::Database
SQL = {
table_exists: "
SELECT name
FROM sqlite_master
WHERE type = 'table'
AND name = ?
",
pragma_foreign_keys: "
PRAGMA foreign_keys = true
",
}
def initialize(path)
super(path)
@savepoint_id = 0_i64
query(SQL[:pragma_foreign_keys])
end
def initialize(path, &block)
super(path)
@savepoint_id = 0_i64
query(SQL[:pragma_foreign_keys])
begin
block.call(self)
ensure
close unless closed?
end
end
def table_exists?(table : String) : Bool
one(SQL[:table_exists], [table]) == table
end
def one(
sql : String,
args = nil : Array(String) | Hash(String, String) | Nil
)
r = nil
run(sql, args) do |rs|
if rs.next
r = rs[0].to_s
end
end
# return result
r
end
def row(
sql : String,
args = nil : Array(String) | Hash(String, String) | Nil
)
r = nil
# exec query
run(sql, args) do |rs|
r = to_row(rs) if rs.next
end
# return result
r
end
def all(
sql : String,
args = nil : Array(String) | Hash(String, String) | Nil,
&block : Hash(String, ::SQLite3::Value) -> \
)
# build statement
run(sql, args) do |rs|
# walk results
while rs.next
# build row and pass it to callback
block.call(to_row(rs))
end
end
nil
end
def query(
sql : String
)
run(sql, nil) do |rs|
# make sure query executes
rs.next
nil
end
end
def query(
sql : String,
args = nil : Array(String) | Hash(String, String) | Nil,
)
run(sql, args) do |rs|
# make sure query executes
rs.next
nil
end
end
#
# NOTE: if you pass a block, be sure to call rs.next at least once,
# or the query will _not_ execute!!!
#
def query(
sql : String,
args = nil : Array(String) | Hash(String, String) | Nil,
&block : ::SQLite3::ResultSet -> \
)
run(sql, args, &block)
end
def transaction(&block)
# get next savepoint id
id = next_savepoint_id
begin
query("SAVEPOINT %s" % [id])
block.call
rescue e
query("ROLLBACK TO %s" % [id])
raise e
ensure
query("RELEASE %s" % [id])
end
end
private def next_savepoint_id : String
# increment savepoint counter
@savepoint_id += 1
# return savepoint id
"guff_savepoint_%s" % [@savepoint_id]
end
private def run(
sql : String,
args : Hash(String, String),
&block : ::SQLite3::ResultSet -> \
)
run(sql, [args], &block)
end
private def run(
sql : String,
args = nil : Array(String | Hash(String, String))?,
&block : ::SQLite3::ResultSet -> \
)
# build statement
puts "sql = %s" % [sql]
st = prepare(sql)
# exec and close statement
if args && args.size > 0
st.execute(args, &block)
else
st.execute(&block)
end
# return result
nil
end
private def to_row(rs)
Hash(String, ::SQLite3::Value).zip(rs.columns, rs.to_a)
end
end
end
|
