Enum FrontendMessage 

pub enum FrontendMessage {
    Startup {
        version: i32,
        params: Vec<(String, String)>,
    },
    PasswordMessage(String),
    SASLInitialResponse {
        mechanism: String,
        data: Vec<u8>,
    },
    SASLResponse(Vec<u8>),
    Query(String),
    Parse {
        name: String,
        query: String,
        param_types: Vec<u32>,
    },
    Bind {
        portal: String,
        statement: String,
        param_formats: Vec<i16>,
        params: Vec<Option<Vec<u8>>>,
        result_formats: Vec<i16>,
    },
    Describe {
        kind: DescribeKind,
        name: String,
    },
    Execute {
        portal: String,
        max_rows: i32,
    },
    Close {
        kind: DescribeKind,
        name: String,
    },
    Sync,
    Flush,
    CopyData(Vec<u8>),
    CopyDone,
    CopyFail(String),
    Terminate,
    CancelRequest {
        process_id: i32,
        secret_key: i32,
    },
    SSLRequest,
}

Messages sent from the client to the PostgreSQL server.

Variants

Startup

Startup message (no type byte) - first message sent after connecting

Fields

version: i32

Protocol version (196608 for 3.0)

params: Vec<(String, String)>

Connection parameters (user, database, etc.)

PasswordMessage(String)

Password response for authentication

SASLInitialResponse

SASL initial response (mechanism selection and initial data)

Fields

mechanism: String

SASL mechanism name (e.g., “SCRAM-SHA-256”)

data: Vec<u8>

Initial response data

SASLResponse(Vec<u8>)

SASL response (continuation data)

Query(String)

Simple query (single SQL string, returns text format)

Parse

Parse a prepared statement (extended query protocol)

Fields

name: String

Statement name (“” for unnamed)

query: String

SQL query with $1, $2, etc. placeholders

param_types: Vec<u32>

Parameter type OIDs (0 for server to infer)

Bind

Bind parameters to a prepared statement

Fields

portal: String

Portal name (“” for unnamed)

statement: String

Statement name to bind to

param_formats: Vec<i16>

Parameter format codes (0=text, 1=binary)

params: Vec<Option<Vec<u8>>>

Parameter values (None for NULL)

result_formats: Vec<i16>

Result format codes (0=text, 1=binary)

Describe

Describe a prepared statement or portal

Fields

kind: DescribeKind

‘S’ for statement, ‘P’ for portal

name: String

Name of statement/portal

Execute

Execute a bound portal

Fields

portal: String

Portal name

max_rows: i32

Maximum rows to return (0 for all)

Close

Close a prepared statement or portal

Fields

kind: DescribeKind

‘S’ for statement, ‘P’ for portal

name: String

Name of statement/portal

Sync

Sync - marks end of extended query, requests ReadyForQuery

Flush

Flush - request server to send all pending output

CopyData(Vec<u8>)

COPY data chunk

CopyDone

COPY operation complete

CopyFail(String)

COPY operation failed

Terminate

Terminate the connection

CancelRequest

Cancel a running query (sent on a separate connection)

Fields

process_id: i32

Backend process ID

secret_key: i32

Secret key from BackendKeyData

SSLRequest

SSL negotiation request

Trait Implementations

impl Clone for FrontendMessage

fn clone(&self) -> FrontendMessage

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for FrontendMessage

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

Formats the value using the given formatter.

impl PartialEq for FrontendMessage

fn eq(&self, other: &FrontendMessage) -> 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 StructuralPartialEq for FrontendMessage