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
|
#!/usr/bin/ruby
require "dbi"
class WeaselDbQueryHandle
def initialize(sth)
@sth = sth
end
def next()
row = @sth.fetch_hash
if row
return row
else
@sth.finish
return nil
end
end
end
class Db
def initialize(database, user, password)
@dbh = DBI.connect("dbi:Pg:#{database}:localhost", user, password);
@dbh['AutoCommit'] = false
@transaction = false
@pre_initial_transaction=true
end
def do(query,*args)
@dbh.do(query,*args)
end
def transaction_begin()
@dbh.do("BEGIN") unless @pre_initial_transaction
@transaction = true
@pre_initial_transaction=false
end
def transaction_commit()
@dbh.do("COMMIT")
@transaction = false
end
def transaction_rollback()
@dbh.do("ROLLBACK")
end
def get_primarykey_name(table);
#return 'ref';
return table+'_id';
end
def update(table, values, keys)
cols = []
vals = []
values.each_pair{ |k,v|
cols << "#{k}=?"
vals << v
}
wheres = []
keys.each_pair{ |k,v|
wheres << "#{k}=?"
vals << v
}
throw "update value set empty" unless cols.size > 0
throw "where clause empty" unless wheres.size > 0
query = "UPDATE #{table} SET #{cols.join(',')} WHERE #{wheres.join(' AND ')}"
transaction_begin unless transaction_before=@transaction
r = @dbh.do(query, *vals)
transaction_commit unless transaction_before
return r
end
def update_row(table, values)
pk_name = get_primarykey_name(table);
throw "Ref not defined" unless values[pk_name]
return update(table, values.clone.delete_if{|k,v| k == pk_name}, { pk_name => values[pk_name] });
end
def insert(table, values)
cols = values.keys
vals = values.values
qmarks = values.values.collect{ '?' }
query = "INSERT INTO #{table} (#{cols.join(',')}) VALUES (#{qmarks.join(',')})"
transaction_begin unless transaction_before=@transaction
@dbh.do(query, *vals)
transaction_commit unless transaction_before
end
def insert_row(table, values)
pk_name = get_primarykey_name(table);
if values[pk_name]
insert(table, values)
else
transaction_begin unless transaction_before=@transaction
row = query_row("SELECT nextval(pg_get_serial_sequence('#{table}', '#{pk_name}')) AS newref");
throw "No newref?" unless row['newref']
values[pk_name] = row['newref']
insert(table, values);
transaction_commit unless transaction_before
end
end
def delete_row(table, ref)
pk_name = get_primarykey_name(table);
query = "DELETE FROM #{table} WHERE #{pk_name}=?"
transaction_begin unless transaction_before=@transaction
@dbh.do(query, ref)
transaction_commit unless transaction_before
end
def query(query, *params)
sth = @dbh.execute(query, *params)
while row = sth.fetch_hash
yield row
end
sth.finish
end
# nil if no results
# hash if one match
# throw otherwise
def query_row(query, *params)
sth = @dbh.execute(query, *params)
row = sth.fetch_hash
if row == nil
sth.finish
return nil
elsif sth.fetch_hash != nil
sth.finish
throw "More than one result when querying for #{query}"
else
sth.finish
return row
end
end
def query_all(query, *params)
sth = @dbh.execute(query, *params)
rows = sth.fetch_all
return nil if rows.size == 0
return rows
end
def query2(query, *params)
sth = @dbh.execute(query, *params)
return WeaselDbQueryHandle.new(sth)
end
end
|