Using bcp to dump table to csv

table-to-tsv.sh

#! /usr/bin/env bash

set -e

#
# Invoke this script; table-to-tsv <database> <schema> <table> -U sa -P 'P455word!!!' -S localhost
#
# The output will be written to stdout, redirecting to where you need your tsv to go. Make sure `bcp`
# is in your path, in the docker images it can be found in /opt/mssql-tools/bin
#

declare database="$1"
declare schema="$2"
declare table="$3"

declare header_query="

    select column_name
    from information_schema.columns
    where '${database}' = table_catalog
      and '${schema}' = table_schema
      and '${table}' = table_name
    order by ordinal_position

"

#
# A few notes here; `bcp` just writes to stdout and nothing else if no file is provided, it will also
# output messages every time with warnings and a summary of what has been done. Which pollutes the
# the output if you want to work with it as a stream. Good for us everything on *nix is a a file and
# that bcp is a little naive in this regard, using `cat` in a subshell as a file will allow us to
# to stdout without adding the extra stuff to it.
#
bcp "$header_query" queryout >(cat) -c -t'' -r'\t' -d "$database" "${@:4}" > /dev/null;
bcp "$schema.$table" out >(cat) -c -t'\t' -r'\n' -d "$database" "${@:4}" >&2