ReQL command: run

Command syntax

query.run(conn[, options], callback)
query.run(conn[, options]) → promise

Description

Run a query on a connection. The callback will get either an error, a single JSON result, or a cursor, depending on the query.

The options can be:

• readMode: One of three possible values affecting the consistency guarantee for the query (default: 'single').
  • 'single' (the default) returns values that are in memory (but not necessarily written to disk) on the primary replica.
  • 'majority' will only return values that are safely committed on disk on a majority of replicas. This requires sending a message to every replica on each read, so it is the slowest but most consistent.
  • 'outdated' will return values that are in memory on an arbitrarily-selected replica. This is the fastest but least consistent.
• timeFormat: what format to return times in (default: 'native'). Set this to 'raw' if you want times returned as JSON objects for exporting.
• profile: whether or not to return a profile of the query’s execution (default: false).
• durability: possible values are 'hard' and 'soft'. In soft durability mode RethinkDB will acknowledge the write immediately after receiving it, but before the write has been committed to disk.
• groupFormat: what format to return grouped_data and grouped_streams in (default: 'native'). Set this to 'raw' if you want the raw pseudotype.
• noreply: set to true to not receive the result object or cursor and return immediately.
• db: the database to run this query against as a string. The default is the database specified in the db parameter to connect (which defaults to test). The database may also be specified with the db command.
• arrayLimit: the maximum numbers of array elements that can be returned by a query (default: 100,000). This affects all ReQL commands that return arrays. Note that it has no effect on the size of arrays being written to the database; those always have an upper limit of 100,000 elements.
• binaryFormat: what format to return binary data in (default: 'native'). Set this to 'raw' if you want the raw pseudotype.
• minBatchRows: minimum number of rows to wait for before batching a result set (default: 8). This is an integer.
• maxBatchRows: maximum number of rows to wait for before batching a result set (default: unlimited). This is an integer.
• maxBatchBytes: maximum number of bytes to wait for before batching a result set (default: 1MB). This is an integer.
• maxBatchSeconds: maximum number of seconds to wait before batching a result set (default: 0.5). This is a float (not an integer) and may be specified to the microsecond.
• firstBatchScaledownFactor: factor to scale the other parameters down by on the first batch (default: 4). For example, with this set to 8 and maxBatchRows set to 80, on the first batch maxBatchRows will be adjusted to 10 (80 / 8). This allows the first batch to return faster.

If no callback is provided, a promise will be returned.

Example: Run a query on the connection conn and log each row in the result to the console.

r.table('marvel').run(conn, function(err, cursor) {
    cursor.each(console.log);
})

Example: Run a query on the connection conn and retrieve all the rows in an array.

r.table('marvel').run(conn, function(err, cursor) {
    if (err) {
        // process error
    }
    else {
        cursor.toArray(function(err, results) {
            if (err) {
                // process error
            }
            else {
                // process the results
            }
        })
    }
})

Alternatively, you can use promises.

r.table('marvel').run(conn).then(function(cursor) {
    return cursor.toArray()
}).then(function(results) {
    // process the results
}).catch(function(err) {
    // process error
})

Example: If you are OK with potentially out of date data from all the tables involved in this query and want potentially faster reads, pass a flag allowing out of date data in an options object. Settings for individual tables will supercede this global setting for all tables in the query.

r.table('marvel').run(conn, {readMode: 'outdated'}, function (err, cursor) {
    ...
});

Example: If you just want to send a write and forget about it, you can set noreply to true in the options. In this case run will return immediately.

r.table('marvel').run(conn, {noreply: true}, function (err, cursor) {
    ...
});

Example: If you want to specify whether to wait for a write to be written to disk (overriding the table’s default settings), you can set durability to 'hard' or 'soft' in the options.

r.table('marvel')
    .insert({ superhero: 'Iron Man', superpower: 'Arc Reactor' })
    .run(conn, {noreply: true, durability: 'soft'}, function (err, cursor) {
        ...
    });

Example: If you do not want a time object to be converted to a native date object, you can pass a time_format flag to prevent it (valid flags are “raw” and “native”). This query returns an object with two fields (epoch_time and $reql_type$) instead of a native date object.

r.now().run(conn, {timeFormat: "raw"}, function (err, result) {
    ...
});

Example: Specify the database to use for the query.

r.table('marvel').run(conn, {db: 'heroes'}).then(function(cursor) {
    return cursor.toArray()
}).then(function(results) {
    // process the results
}).catch(function(err) {
    // process error
})

This is equivalent to using the db command to specify the database:

r.db('heroes').table('marvel').run(conn) ...

Example: Change the batching parameters for this query.

r.table('marvel').run(conn, {
    maxBatchRows: 16,
    maxBatchBytes: 2048
}, callback);

Related commands

• connect

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