Struct rsmgclient::Connection

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pub struct Connection { /* private fields */ }

Expand description

Encapsulates a database connection.

Examples

use rsmgclient::{ConnectParams, Connection};

let connect_params = ConnectParams {
    host: Some(String::from("localhost")),
    ..Default::default()
};
let mut connection = Connection::connect(&connect_params)?;

let query = "CREATE (u:User {name: 'Alice'})-[l:Likes]->(m:Software {name: 'Memgraph'}) RETURN u, l, m";
connection.execute(query, None)?;

let records = connection.fetchall()?;
for value in &records[0].values {
    println!("{}", value);
}

connection.commit()?;

Implementations§

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impl Connection

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pub fn init()

Initializes underlying mgclient.

Should be called at the beginning of each process using the client.

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pub fn finalize()

Finalizes underlying mgclient.

Should be called at the end of each process using the client.

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pub fn lazy(&self) -> bool

Returns whether connection is executing lazily.

If false, queries are not executed lazily. After running execute, records are immediately pulled.

If true queries are executed lazily. After running execute, records will only get pulled until fetch functions are called.

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pub fn autocommit(&self) -> bool

Getter for autocommit field.

If true all queries are automatically committed.

If false queries are executed inside a transaction. Before executing first query, execute runs begin on database. After that user needs to commit or roll back manually, using commit and rollback functions.

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pub fn arraysize(&self) -> u32

Getter for arraysize field.

Default amount of rows to get fetched when calling fetchmany. Initial value is 1.

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pub fn status(&self) -> ConnectionStatus

Returns current connection status.

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pub fn summary(&self) -> Option<HashMap<String, Value>>

Returns query summary if it is present.

Query summary is present after query has completed execution( all records have been fetched). Executing new query will remove previous query summary.

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pub fn set_lazy(&mut self, lazy: bool)

Setter for lazy field.

Panics

Panics if connection is not in a Ready status.

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pub fn set_autocommit(&mut self, autocommit: bool)

Setter for autocommit field.

Panics

Panics if connection is not in a Ready status.

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pub fn set_arraysize(&mut self, arraysize: u32)

Setter for arraysize field.

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pub fn connect(param_struct: &ConnectParams) -> Result<Connection, MgError>

Creates a connection to database using provided connection parameters.

Returns Connection if connection to database is successfully established, otherwise returns error with explanation what went wrong.

Examples

use rsmgclient::{ConnectParams, Connection};

let connect_params = ConnectParams {
    host: Some(String::from("localhost")),
    ..Default::default()
};

let mut connection = Connection::connect(&connect_params)?;

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pub fn execute_without_results(&mut self, query: &str) -> Result<(), MgError>

Fully Executes provided query but doesn’t return any results even if they exist.

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pub fn execute( &mut self, query: &str, params: Option<&HashMap<String, QueryParam>> ) -> Result<Vec<String>, MgError>

Executes provided query using parameters (if provided) and returns names of columns.

After execution records need to get fetched using fetch methods. Connection needs to be in status Ready or InTransaction. Error is returned if connection is not ready, query is invalid or there was an error in communication with server.

If connection is not lazy will also fetch and store all records. If connection has autocommit set to false and is not in a transaction will also start a transaction.

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