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
/**
Trait representing a drop table builder.
*/
pub trait DropTable {
/**
Drops the table only, if it exists.
*/
fn if_exists(self) -> Self;
/**
This method is used to build the drop table statement.
*/
fn build(self) -> String;
}
/**
The representation of data of the drop table statement.
*/
#[derive(Debug, Copy, Clone)]
pub struct DropTableData<'until_build> {
pub(crate) name: &'until_build str,
pub(crate) if_exists: bool,
}
/**
Implementation of the [DropTable] trait for the different implementations.
Should only be constructed via [crate::DBImpl::drop_table].
*/
#[derive(Debug)]
pub enum DropTableImpl<'until_build> {
/**
SQLite representation of the DROP TABLE operation.
*/
#[cfg(feature = "sqlite")]
SQLite(DropTableData<'until_build>),
/**
Postgres representation of the DROP TABLE operation.
*/
#[cfg(feature = "postgres")]
Postgres(DropTableData<'until_build>),
}
impl DropTable for DropTableImpl<'_> {
fn if_exists(mut self) -> Self {
match self {
#[cfg(feature = "sqlite")]
DropTableImpl::SQLite(ref mut d) => d.if_exists = true,
#[cfg(feature = "postgres")]
DropTableImpl::Postgres(ref mut d) => d.if_exists = true,
};
self
}
fn build(self) -> String {
match self {
#[cfg(feature = "sqlite")]
DropTableImpl::SQLite(d) => format!(
"DROP TABLE \"{}\"{};",
d.name,
if d.if_exists { " IF EXISTS" } else { "" }
),
#[cfg(feature = "postgres")]
DropTableImpl::Postgres(d) => format!(
"DROP TABLE \"{}\"{};",
d.name,
if d.if_exists { " IF EXISTS" } else { "" }
),
}
}
}