Lua driver for Exasol

• Index

Contents

• Local Functions
• Methods

Classes

• luasql.exasol.Connection
• luasql.exasol.ConnectionProperties
• luasql.exasol.Cursor
• luasql.exasol.CursorData
• luasql.exasol.Environment
• luasql.exasol.ExasolWebsocket
• luasql.exasol.Websocket
• luasql.exasol.WebsocketDatahandler

Modules

• luasql.exasol
• luasql.exasol.constants
• luasql.exasol.util

Examples

• examples.lua

Class luasql.exasol.Websocket

This internal class represents a websocket connection that allows sending and receiving messages.

Local Functions

luasql.exasol.websocket.create()	Creates a new instance of this class that is not yet opened/connected.
luasql.exasol.websocket.recoverable_connection_error(err)	Check if the given error received during connection is recoverable, i.e.
luasql.exasol.websocket.connect_with_retry(url, websocket_options, remaining_retries)	Create a connection to a websocket url with the given number of retries.

Methods

luasql.exasol.websocket:connect(url, connection_properties)	Open a websocket connection to the given URL, using maximum 3 retries if a connection fails.
luasql.exasol.websocket:_wait_for_response(timeout_seconds)	Wait until we receive a response.
luasql.exasol.websocket:send_raw(payload, ignore_response)	Send the given payload and optionally wait for the response and return the response.
luasql.exasol.websocket:close()	Disconnect from the server and close this websocket.

Local Functions

Methods

luasql.exasol.websocket.create() line 20

Creates a new instance of this class that is not yet opened/connected.

Returns:

luasql.exasol.Websocket the new websocket.

luasql.exasol.websocket.recoverable_connection_error(err) line 32

Check if the given error received during connection is recoverable, i.e. we can try to connect again later.

Parameters:

• err string the received error

Returns:

boolean true if we can retry the connection, false if this is a permanent error that does not disappear

luasql.exasol.websocket.connect_with_retry(url, websocket_options, remaining_retries) line 43

Create a connection to a websocket url with the given number of retries.

Parameters:

• url string the websocket url to connect to, e.g. "wss://host:1234"
• websocket_options table the options passed to LuWS when opening a socket, see LuWS documentation for details.
• remaining_retries number the remaining number of retries. If this is 0, there will be no retry.

Returns:

luasql.exasol.Websocket the open websocket connection

Raises:

an error if connection does not succeed after the given number of retries

Methods

luasql.exasol.websocket:connect(url, connection_properties) line 71

Open a websocket connection to the given URL, using maximum 3 retries if a connection fails.

Parameters:

• url string the websocket url to connect to, e.g. "wss://host:1234"
• connection_properties luasql.exasol.ConnectionProperties the connection properties

Returns:

luasql.exasol.Websocket the open websocket connection

Raises:

an error if connection does not succeed after the given number of retries

luasql.exasol.websocket:_wait_for_response(timeout_seconds) line 87

Wait until we receive a response. This is implemented with busy waiting until wsreceive indicates that data was received.

Parameters:

• timeout_seconds number the number of seconds to wait for a response

Returns:

nil or table nil if a response was received within the timeout or an error if the response did not arrive within the timeout or an error occured while waiting

luasql.exasol.websocket:send_raw(payload, ignore_response) line 125

Send the given payload and optionally wait for the response and return the response.

Parameters:

• payload string the payload to send
• ignore_response boolean false if we expect a response.

Returns:

1. string the received response or nil if ignore_response was true or an error occurred.
2. nil or table nil if the operation was successful, otherwise the error that occured

luasql.exasol.websocket:close() line 149

Disconnect from the server and close this websocket.