.indexes property for introspecting indexes

This commit is contained in:
Simon Willison 2018-07-31 18:31:29 -07:00
commit c611ed80d2
3 changed files with 46 additions and 1 deletions

View file

@ -167,6 +167,16 @@ The ``.schema`` property outputs the table's schema as a SQL string::
FOREIGN KEY ("qCareAssistant") REFERENCES [qCareAssistant](id),
FOREIGN KEY ("qLegalStatus") REFERENCES [qLegalStatus](id))
The ``.indexes`` property shows you all indexes created for a table::
>>> db["Street_Tree_List"].indexes
[Index(seq=0, name='"Street_Tree_List_qLegalStatus"', unique=0, origin='c', partial=0, columns=['qLegalStatus']),
Index(seq=1, name='"Street_Tree_List_qCareAssistant"', unique=0, origin='c', partial=0, columns=['qCareAssistant']),
Index(seq=2, name='"Street_Tree_List_qSiteInfo"', unique=0, origin='c', partial=0, columns=['qSiteInfo']),
Index(seq=3, name='"Street_Tree_List_qSpecies"', unique=0, origin='c', partial=0, columns=['qSpecies']),
Index(seq=4, name='"Street_Tree_List_qCaretaker"', unique=0, origin='c', partial=0, columns=['qCaretaker']),
Index(seq=5, name='"Street_Tree_List_PlantType"', unique=0, origin='c', partial=0, columns=['PlantType'])]
Enabling full-text search
=========================

View file

@ -8,6 +8,7 @@ Column = namedtuple(
ForeignKey = namedtuple(
"ForeignKey", ("table", "column", "other_table", "other_column")
)
Index = namedtuple("Index", ("seq", "name", "unique", "origin", "partial", "columns"))
class Database:
@ -122,6 +123,18 @@ class Table:
"select sql from sqlite_master where name = ?", (self.name,)
).fetchone()[0]
@property
def indexes(self):
sql = "select * from pragma_index_list(?)"
indexes = []
for row in list(self.db.conn.execute(sql, (self.name,)).fetchall()):
column_sql = "select name from pragma_index_info(?) order by seqno"
columns = [
r[0] for r in self.db.conn.execute(column_sql, (row[1],)).fetchall()
]
indexes.append(Index(*(row + (columns,))))
return indexes
def create(self, columns, pk=None, foreign_keys=None):
columns = {name: value for (name, value) in columns.items()}
self.db.create_table(self.name, columns, pk=pk, foreign_keys=foreign_keys)

View file

@ -1,4 +1,5 @@
from .fixtures import existing_db
from .fixtures import existing_db, fresh_db
from sqlite_utils.db import Index
def test_table_names(existing_db):
@ -27,3 +28,24 @@ def test_schema(existing_db):
def test_table_repr(existing_db):
assert "<Table foo>" == repr(existing_db["foo"])
def test_indexes(fresh_db):
fresh_db.conn.executescript(
"""
create table Gosh (c1 text, c2 text, c3 text);
create index Gosh_c1 on Gosh(c1);
create index Gosh_c2c3 on Gosh(c2, c3);
"""
)
assert [
Index(
seq=0,
name="Gosh_c2c3",
unique=0,
origin="c",
partial=0,
columns=["c2", "c3"],
),
Index(seq=1, name="Gosh_c1", unique=0, origin="c", partial=0, columns=["c1"]),
] == fresh_db["Gosh"].indexes