Enum odbc_api::buffers::BufferKind

source · [−]

pub enum BufferKind {
Show 14 variants    Binary {
        length: usize,
    },
    Text {
        max_str_len: usize,
    },
    WText {
        max_str_len: usize,
    },
    F64,
    F32,
    Date,
    Time,
    Timestamp,
    I8,
    I16,
    I32,
    I64,
    U8,
    Bit,
}

Expand description

This class is used together with crate::buffers::BufferDescription to specify the layout of buffers bound to ODBC cursors and statements.

Variants

`Binary`

Fields

length: usize

Maximum number of bytes per value.

Variable sized binary buffer, holding up to length bytes per value.

`Text`

Fields

max_str_len: usize

Maximum string length. Terminating zero is excluded, i.e. memory for it will be implicitly allocated if required.

Text buffer holding strings with binary length of up to max_str_len.

`WText`

Fields

max_str_len: usize

Maximum string length. Terminating zero is excluded, i.e. memory for it will be implicitly allocated if required.

UTF-16 encoded text buffer holding strings with length of up to max_str_len. Length is in terms of 2-Byte characters.

`F64`

64 bit floating point

`F32`

32 bit floating point

`Date`

Describes a buffer holding crate::sys::Date values.

`Time`

Describes a buffer holding crate::sys::Time values.

`Timestamp`

Describes a buffer holding crate::sys::Timestamp values.

`I8`

Signed 8 Bit integer

`I16`

Signed 16 Bit integer

`I32`

Signed 32 Bit integer

`I64`

Signed 64 Bit integer

`U8`

Unsigned 8 Bit integer

`Bit`

Can either be zero or one

Implementations

source

impl BufferKind

source

pub fn from_data_type(data_type: DataType) -> Option<Self>

Describe a buffer which fits best the SQL Data Type.

use odbc_api::{DataType, buffers::BufferKind};

assert_eq!(BufferKind::from_data_type(DataType::Unknown), None);
assert_eq!(
    BufferKind::from_data_type(DataType::Numeric { precision: 2, scale: 0 }),
    Some(BufferKind::I8)
);
assert_eq!(
    BufferKind::from_data_type(DataType::Numeric { precision: 9, scale: 0 }),
    Some(BufferKind::I32)
);
assert_eq!(
    BufferKind::from_data_type(DataType::Numeric { precision: 18, scale: 0 }),
    Some(BufferKind::I64)
);
assert_eq!(
    BufferKind::from_data_type(DataType::Numeric { precision: 20, scale: 5 }),
    Some(BufferKind::Text { max_str_len: 20 + 2 })
);
assert_eq!(
    BufferKind::from_data_type(DataType::Varchar { length: 42 }),
    Some(BufferKind::Text { max_str_len: 42 })
);
// We do not care about the encoding in the datasource. WVarchar is mapped to `Text`, too
// (instead of `WText`).
assert_eq!(
    BufferKind::from_data_type(DataType::WVarchar { length: 42 }),
    Some(BufferKind::Text { max_str_len: 42 })
);
assert_eq!(
    BufferKind::from_data_type(DataType::BigInt),
    Some(BufferKind::I64)
);
assert_eq!(
    BufferKind::from_data_type(DataType::Integer),
    Some(BufferKind::I32)
);
assert_eq!(
    BufferKind::from_data_type(DataType::SmallInt),
    Some(BufferKind::I16)
);
assert_eq!(
    BufferKind::from_data_type(DataType::TinyInt),
    Some(BufferKind::I8)
);
assert_eq!(
    BufferKind::from_data_type(DataType::Float { precision : 24 }),
    Some(BufferKind::F32)
);
assert_eq!(
    BufferKind::from_data_type(DataType::Float { precision : 53 }),
    Some(BufferKind::F64)
);
assert_eq!(
    BufferKind::from_data_type(DataType::Double),
    Some(BufferKind::F64)
);
assert_eq!(
    BufferKind::from_data_type(DataType::Date),
    Some(BufferKind::Date)
);
assert_eq!(
    BufferKind::from_data_type(DataType::Time { precision: 0 }),
    Some(BufferKind::Time)
);
assert_eq!(
    BufferKind::from_data_type(DataType::Bit),
    Some(BufferKind::Bit)
);
assert_eq!(
    BufferKind::from_data_type(DataType::Time { precision: 3 }),
    Some(BufferKind::Text { max_str_len: 12 })
);
assert_eq!(
    BufferKind::from_data_type(DataType::Timestamp { precision: 3 }),
    Some(BufferKind::Timestamp)
);