--load-extension option for sqlite-utils query, closes #134

docs/cli.rst

@@ -83,6 +83,11 @@ You can run queries against a temporary in-memory database by passing ``:memory:
     $ sqlite-utils :memory: "select sqlite_version()"
     [{"sqlite_version()": "3.29.0"}]
 
+You can load SQLite extension modules using the `--load-extension` option::
+
+    $ sqlite-utils :memory: "select spatialite_version()" --load-extension=/usr/local/lib/mod_spatialite.dylib
+    [{"spatialite_version()": "4.3.0a"}]
+
 .. _cli_json_values:
 
 Nested JSON values

sqlite_utils/cli.py

@@ -719,9 +719,29 @@ def drop_view(path, view):
     type=(str, str),
     help="Named :parameters for SQL query",
 )
-def query(path, sql, nl, arrays, csv, no_headers, table, fmt, json_cols, raw, param):
+@click.option(
+    "--load-extension", multiple=True, help="SQLite extensions to load",
+)
+def query(
+    path,
+    sql,
+    nl,
+    arrays,
+    csv,
+    no_headers,
+    table,
+    fmt,
+    json_cols,
+    raw,
+    param,
+    load_extension,
+):
     "Execute SQL query and return the results as JSON"
     db = sqlite_utils.Database(path)
+    if load_extension:
+        db.conn.enable_load_extension(True)
+        for ext in load_extension:
+            db.conn.load_extension(ext)
     with db.conn:
         cursor = db.conn.execute(sql, dict(param))
         if cursor.description is None:

tests/test_cli.py

@@ -4,7 +4,7 @@
 import json
 import os
 import pytest
-from sqlite_utils.utils import sqlite3
+from sqlite_utils.utils import sqlite3, find_spatialite
 
 from .utils import collapse_whitespace
 
@@ -885,6 +885,29 @@ def test_query_raw(db_path, content, is_binary):
         assert result.output == str(content)
 
 
+@pytest.mark.skipif(not find_spatialite(), reason="Could not find SpatiaLite extension")
+@pytest.mark.skipif(
+    not hasattr(sqlite3.Connection, "enable_load_extension"),
+    reason="sqlite3.Connection missing enable_load_extension",
+)
+def test_query_load_extension():
+    # Without --load-extension:
+    result = CliRunner().invoke(cli.cli, [":memory:", "select spatialite_version()"])
+    assert result.exit_code == 1
+    assert "no such function: spatialite_version" in repr(result)
+    # With --load-extension:
+    result = CliRunner().invoke(
+        cli.cli,
+        [
+            ":memory:",
+            "select spatialite_version()",
+            "--load-extension={}".format(find_spatialite()),
+        ],
+    )
+    assert result.exit_code == 0, result.stdout
+    assert ["spatialite_version()"] == list(json.loads(result.output)[0].keys())
+
+
 def test_query_memory_does_not_create_file(tmpdir):
     owd = os.getcwd()
     try: