Interpolates JSON data into SQL strings from the command line. For generating SQL statements to pass to DB client programs like psql, mysql, and sqlite3 via Unix pipelines or shell scripts. A faster, lighter-weight alternative to writing ad-hoc, monolithic programs with database and ORM libraries.

A template file with this interpolation syntax:

INSERT into titles (title, year, rating, created)
VALUES (:title, :year, :ratings.imdb, DEFAULT);

combined with this JSON stream on STDIN

{
  "title": "Terminator 2: 'Judgment Day'",
  "year": 1991,
  "stars": [
    {"name": "Arnold Schwarzenegger"},
    {"name": "Linda Hamilton"}
  ],
  "ratings": {
    "imdb": 8.5
  },
  "created": "2014-12-04T10:10:10Z"
}
{
  "title": "Interstellar",
  "year": 2014,
  "stars": [
    {"name":"Matthew McConaughey"},
    {"name":"Anne Hathaway"}
  ],
  "ratings": {
    "imdb": 8.9
  }
}

generates this output:

INSERT into titles (title, year, rating, created)
VALUES ('Terminator 2: ''Judgment Day''', 1991, 8.5, DEFAULT);
INSERT into titles (title, year, rating, created)
VALUES ('Interstellar', 2014, 8.9, DEFAULT);

Install

cabal install jsonsql

Usage

jsonsql
Usage: jsonsql (TEMPLATE | -f FILE)
  Inject JSON into SQL template strings
Available options:
  -h,--help                Show this help text
  -f FILE                  Template file

Array joining

If a key path evaluates to an array of values, specify a <delimiter> to have the the values converted into strings, joined by the delimiter, and then output as a string.

INSERT into titles (title, year, rating, stars<,>, created)
VALUES (:title, :year, :ratings.imdb, :stars.name, DEFAULT);

INSERT into titles (title, year, rating, stars, created)
VALUES ('Terminator 2: ''Judgment Day''', 1991, 8.5, 'Arnold Schwarzenegger,Linda Hamilton', DEFAULT);
INSERT into titles (title, year, rating, stars, created)
VALUES ('Interstellar', 2014, 8.9, 'Matthew McConaughey,Anne Hathaway', DEFAULT);

JSON literal interpolation

If a key path terminates in a JSON object or array (without a array delimiter specified), a JSON literal will be interpolated:

template:

INSERT into titles (title, stars)
VALUES (:title, :stars);

output:

INSERT into titles (title, stars)
VALUES ('Terminator 2: ''Judgment Day''', '[{"name":"Arnold Schwarzenegger"},{"name":"Linda Hamilton"}]');
INSERT into titles (title, stars)
VALUES ('Interstellar', '[{"name":"Matthew McConaughey"},{"name":"Anne Hathaway"}]');

To interpolate the base object as a literal JSON string, use :. as the keypath.

Do NOT put quotes around the placeholder for a literal JSON interpolation.

Author

Daniel Choi dhchoi@gmail.com