Enum DatabaseType 

pub enum DatabaseType {
    PostgreSQL,
    MySQL,
    SQLite,
    MSSQL,
}

Build a parameter placeholder for a given database type.

Variants

PostgreSQL

PostgreSQL uses $1, $2, etc.

MySQL

MySQL uses ?, ?, etc.

SQLite

SQLite uses ?, ?, etc.

MSSQL

MSSQL uses @P1, @P2, etc.

Implementations

impl DatabaseType

pub fn placeholder(&self, index: usize) -> Cow<'static, str>

Get the parameter placeholder for this database type.

For MySQL and SQLite, this returns a borrowed static string (zero allocation). For PostgreSQL with index 1-128, this returns a borrowed static string (zero allocation). For PostgreSQL with index > 128, this returns an owned formatted string.

Examples

use prax_query::sql::DatabaseType;

// PostgreSQL uses numbered placeholders (zero allocation for 1-128)
assert_eq!(DatabaseType::PostgreSQL.placeholder(1).as_ref(), "$1");
assert_eq!(DatabaseType::PostgreSQL.placeholder(5).as_ref(), "$5");
assert_eq!(DatabaseType::PostgreSQL.placeholder(100).as_ref(), "$100");

// MySQL and SQLite use ? (zero allocation)
assert_eq!(DatabaseType::MySQL.placeholder(1).as_ref(), "?");
assert_eq!(DatabaseType::SQLite.placeholder(1).as_ref(), "?");

pub fn placeholder_string(&self, index: usize) -> String

Get the parameter placeholder as a String.

This is a convenience method that always allocates. Prefer placeholder() when you can work with Cow<str> to avoid unnecessary allocations.

Trait Implementations

impl Clone for DatabaseType

fn clone(&self) -> DatabaseType

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for DatabaseType

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

Formats the value using the given formatter.

impl Default for DatabaseType

fn default() -> DatabaseType

Returns the “default value” for a type.

impl Hash for DatabaseType

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

Feeds this value into the given Hasher.

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

where H: Hasher, Self: Sized,

Feeds a slice of this type into the given Hasher.

impl PartialEq for DatabaseType

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

Tests for self and other values to be equal, and is used by ==.

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

Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl Copy for DatabaseType

impl Eq for DatabaseType

impl StructuralPartialEq for DatabaseType