sqlite-utils indexes command, refs #263

docs/cli.rst

@@ -293,6 +293,33 @@ It takes the same options as the ``tables`` command:
 * ``--tsv``
 * ``--table``
 
+.. _cli_indexes:
+
+Listing indexes
+===============
+
+The ``indexes`` command lists any indexes configured for the database::
+
+    $ sqlite-utils indexes covid.db --table
+    table                             index_name                                                seqno    cid  name                 desc  coll      key
+    --------------------------------  ------------------------------------------------------  -------  -----  -----------------  ------  ------  -----
+    johns_hopkins_csse_daily_reports  idx_johns_hopkins_csse_daily_reports_combined_key             0     12  combined_key            0  BINARY      1
+    johns_hopkins_csse_daily_reports  idx_johns_hopkins_csse_daily_reports_country_or_region        0      1  country_or_region       0  BINARY      1
+    johns_hopkins_csse_daily_reports  idx_johns_hopkins_csse_daily_reports_province_or_state        0      2  province_or_state       0  BINARY      1
+    johns_hopkins_csse_daily_reports  idx_johns_hopkins_csse_daily_reports_day                      0      0  day                     0  BINARY      1
+    ny_times_us_counties              idx_ny_times_us_counties_date                                 0      0  date                    1  BINARY      1
+    ny_times_us_counties              idx_ny_times_us_counties_fips                                 0      3  fips                    0  BINARY      1
+    ny_times_us_counties              idx_ny_times_us_counties_county                               0      1  county                  0  BINARY      1
+    ny_times_us_counties              idx_ny_times_us_counties_state                                0      2  state                   0  BINARY      1
+
+It shows indexes across all tables. To see indexes for specific tables, list those after the database::
+
+    $ sqlite-utils indexes covid.db johns_hopkins_csse_daily_reports --table
+
+The command defaults to only showing the columns that are explicitly part of the index. To also include auxiliary columns use the ``--aux`` option - these columns will be listed with a ``key`` of ``0``.
+
+The command takes the same format options as the ``tables`` and ``views`` commands.
+
 .. _cli_triggers:
 
 Listing triggers

sqlite_utils/cli.py

@@ -1287,6 +1287,67 @@ def triggers(
     )
 
 
+@cli.command()
+@click.argument(
+    "path",
+    type=click.Path(file_okay=True, dir_okay=False, allow_dash=False),
+    required=True,
+)
+@click.argument("tables", nargs=-1)
+@click.option("--aux", is_flag=True, help="Include auxiliary columns")
+@output_options
+@load_extension_option
+@click.pass_context
+def indexes(
+    ctx,
+    path,
+    tables,
+    aux,
+    nl,
+    arrays,
+    csv,
+    tsv,
+    no_headers,
+    table,
+    fmt,
+    json_cols,
+    load_extension,
+):
+    "Show indexes for this database"
+    sql = """
+    select
+      sqlite_master.name as "table",
+      indexes.name as index_name,
+      xinfo.*
+    from sqlite_master
+      join pragma_index_list(sqlite_master.name) indexes
+      join pragma_index_xinfo(index_name) xinfo
+    where
+      sqlite_master.type = 'table'
+    """
+    if tables:
+        quote = sqlite_utils.Database(memory=True).quote
+        sql += " and sqlite_master.name in ({})".format(
+            ", ".join(quote(table) for table in tables)
+        )
+    if not aux:
+        sql += " and xinfo.key = 1"
+    ctx.invoke(
+        query,
+        path=path,
+        sql=sql,
+        nl=nl,
+        arrays=arrays,
+        csv=csv,
+        tsv=tsv,
+        no_headers=no_headers,
+        table=table,
+        fmt=fmt,
+        json_cols=json_cols,
+        load_extension=load_extension,
+    )
+
+
 @cli.command()
 @click.argument(
     "path",

tests/test_cli.py

@@ -1802,6 +1802,83 @@ def test_search(tmpdir, fts, extra_arg, expected):
     assert result.output.replace("\r", "") == expected
 
 
+def test_indexes(tmpdir):
+    db_path = str(tmpdir / "test.db")
+    db = Database(db_path)
+    db.conn.executescript(
+        """
+        create table Gosh (c1 text, c2 text, c3 text);
+        create index Gosh_idx on Gosh(c2, c3 desc);
+    """
+    )
+    result = CliRunner().invoke(
+        cli.cli,
+        ["indexes", str(db_path)],
+        catch_exceptions=False,
+    )
+    assert result.exit_code == 0
+    assert json.loads(result.output) == [
+        {
+            "table": "Gosh",
+            "index_name": "Gosh_idx",
+            "seqno": 0,
+            "cid": 1,
+            "name": "c2",
+            "desc": 0,
+            "coll": "BINARY",
+            "key": 1,
+        },
+        {
+            "table": "Gosh",
+            "index_name": "Gosh_idx",
+            "seqno": 1,
+            "cid": 2,
+            "name": "c3",
+            "desc": 1,
+            "coll": "BINARY",
+            "key": 1,
+        },
+    ]
+    result2 = CliRunner().invoke(
+        cli.cli,
+        ["indexes", str(db_path), "--aux"],
+        catch_exceptions=False,
+    )
+    assert result2.exit_code == 0
+    assert json.loads(result2.output) == [
+        {
+            "table": "Gosh",
+            "index_name": "Gosh_idx",
+            "seqno": 0,
+            "cid": 1,
+            "name": "c2",
+            "desc": 0,
+            "coll": "BINARY",
+            "key": 1,
+        },
+        {
+            "table": "Gosh",
+            "index_name": "Gosh_idx",
+            "seqno": 1,
+            "cid": 2,
+            "name": "c3",
+            "desc": 1,
+            "coll": "BINARY",
+            "key": 1,
+        },
+        {
+            "table": "Gosh",
+            "index_name": "Gosh_idx",
+            "seqno": 2,
+            "cid": -1,
+            "name": None,
+            "desc": 0,
+            "coll": "BINARY",
+            "key": 0,
+        },
+    ]
+
+
 _TRIGGERS_EXPECTED = '[{"name": "blah", "table": "articles", "sql": "CREATE TRIGGER blah AFTER INSERT ON articles\\nBEGIN\\n    UPDATE counter SET count = count + 1;\\nEND"}]\n'