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NameLimit

Enum NameLimit 

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pub enum NameLimit {
    Bytes(u16),
    Characters(u16),
}
Expand description

The longest name a database keeps, in the unit it measures names by.

Postgres measures a name in bytes, MySQL and MariaDB in characters, so a name of accented letters can fit one database and not the other.

§Examples

use ruststream_sqlx_dialect::{
    Dialect, NameLimit, Param, Statement, StatementError, TableSpec,
};

/// SQL Server, a database without a built-in dialect.
#[derive(Debug)]
pub struct Mssql;

impl Mssql {
    // SQL Server keeps a name of up to 128 characters.
    fn named<'n>(&self, name: &'n str) -> Result<&'n str, StatementError> {
        if name.chars().count() <= 128 {
            return Ok(name);
        }
        Err(StatementError::IdentifierTooLong {
            dialect: self.name(),
            identifier: name.to_owned(),
            limit: NameLimit::Characters(128),
        })
    }
}

impl Dialect for Mssql {
    fn name(&self) -> &'static str {
        "mssql"
    }

    fn ack(&self, spec: &TableSpec<'_>) -> Result<Statement, StatementError> {
        let mut sql = String::from("DELETE FROM ");
        self.quote_into(self.named(spec.table())?, &mut sql);
        sql.push_str(" WHERE ");
        self.quote_into(self.named(spec.id().name())?, &mut sql);
        sql.push_str(" = @p1");
        Ok(Statement::new(sql, [Param::Id]))
    }
}

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Bytes(u16)

At most this many bytes of UTF-8.

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Characters(u16)

At most this many characters.

Trait Implementations§

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impl Clone for NameLimit

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fn clone(&self) -> Self

Returns a duplicate of the value. Read more
1.0.0 (const: unstable) · Source§

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source. Read more
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impl Copy for NameLimit

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impl Debug for NameLimit

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fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter. Read more
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impl Display for NameLimit

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fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter. Read more
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impl Eq for NameLimit

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impl Hash for NameLimit

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fn hash<__H: Hasher>(&self, state: &mut __H)

Feeds this value into the given Hasher. Read more
1.3.0 · Source§

fn hash_slice<H>(data: &[Self], state: &mut H)
where H: Hasher, Self: Sized,

Feeds a slice of this type into the given Hasher. Read more
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impl PartialEq for NameLimit

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fn eq(&self, other: &Self) -> bool

Equality operator ==. Read more
1.0.0 (const: unstable) · Source§

fn ne(&self, other: &Rhs) -> bool

Inequality operator !=. Read more
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impl StructuralPartialEq for NameLimit

Auto Trait Implementations§

Blanket Implementations§

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impl<T> Any for T
where T: 'static + ?Sized,

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fn type_id(&self) -> TypeId

Gets the TypeId of self. Read more
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impl<T> Borrow<T> for T
where T: ?Sized,

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fn borrow(&self) -> &T

Immutably borrows from an owned value. Read more
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impl<T> BorrowMut<T> for T
where T: ?Sized,

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fn borrow_mut(&mut self) -> &mut T

Mutably borrows from an owned value. Read more
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impl<T> CloneToUninit for T
where T: Clone,

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unsafe fn clone_to_uninit(&self, dest: *mut u8)

🔬This is a nightly-only experimental API. (clone_to_uninit)
Performs copy-assignment from self to dest. Read more
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impl<T> From<T> for T

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fn from(t: T) -> T

Returns the argument unchanged.

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impl<T, U> Into<U> for T
where U: From<T>,

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fn into(self) -> U

Calls U::from(self).

That is, this conversion is whatever the implementation of From<T> for U chooses to do.

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impl<T> ToOwned for T
where T: Clone,

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type Owned = T

The resulting type after obtaining ownership.
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fn to_owned(&self) -> T

Creates owned data from borrowed data, usually by cloning. Read more
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fn clone_into(&self, target: &mut T)

Uses borrowed data to replace owned data, usually by cloning. Read more
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impl<T> ToString for T
where T: Display + ?Sized,

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fn to_string(&self) -> String

Converts the given value to a String. Read more
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impl<T, U> TryFrom<U> for T
where U: Into<T>,

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type Error = !

The type returned in the event of a conversion error.
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fn try_from(value: U) -> Result<T, !>

Performs the conversion.
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impl<T, U> TryInto<U> for T
where U: TryFrom<T>,

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type Error = <U as TryFrom<T>>::Error

The type returned in the event of a conversion error.
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fn try_into(self) -> Result<U, <U as TryFrom<T>>::Error>

Performs the conversion.