Struct BackendClient 

pub struct BackendClient {
    pub server_parameters: HashMap<String, String>,
    pub backend_pid: Option<u32>,
    pub backend_secret: Option<u32>,
    /* private fields */
}

An established, authenticated client connection to a backend.

Fields

server_parameters: HashMap<String, String>

Parameter values the server sent during startup (client_encoding, server_version, TimeZone, …). Useful for diagnostics.

backend_pid: Option<u32>

BackendKeyData cached for potential cancel requests.

backend_secret: Option<u32>

Implementations

impl BackendClient

pub async fn connect(cfg: &BackendConfig) -> BackendResult<Self>

Connect, TLS-negotiate, authenticate, and drain server-initialisation frames through ReadyForQuery. On success the client is idle and ready to run SQL.

pub async fn simple_query(&mut self, sql: &str) -> BackendResult<QueryResult>

Run a simple-query (SQL text) and collect every resulting row into a QueryResult. For statements that don’t return rows (DDL, SET, etc.) rows will be empty and command_tag carries the completion string.

pub async fn query_with_params( &mut self, sql: &str, params: &[ParamValue], ) -> BackendResult<QueryResult>

Like simple_query but substitutes $1, $2, … with text-format literals before sending. We stick to simple-query rather than the extended protocol to keep the surface narrow.

pub async fn query_scalar(&mut self, sql: &str) -> BackendResult<TextValue>

Shorthand for a scalar lookup: runs sql, expects 1 column, 1 row.

pub async fn execute(&mut self, sql: &str) -> BackendResult<String>

Run a statement with no result set (DDL, SET, DO). Returns the command tag (e.g. "SET", "CREATE TABLE").

pub async fn close(self)

Close the connection gracefully (send Terminate, close socket).

pub fn is_tls(&self) -> bool

Report whether the underlying connection is over TLS.