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Drop support for sqlite<3.22 as well

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This commit is contained in:
Richard van der Hoff 2021-04-08 13:45:19 +01:00
parent abade34633
commit 3ada9b4264
6 changed files with 14 additions and 92 deletions
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62
synapse/storage/database.py
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@ -2060,68 +2060,20 @@ KV = TypeVar("KV")
def make_tuple_comparison_clause(
database_engine: BaseDatabaseEngine, keys: List[Tuple[str, KV]]
_database_engine: BaseDatabaseEngine, keys: List[Tuple[str, KV]]
) -> Tuple[str, List[KV]]:
"""Returns a tuple comparison SQL clause
Depending what the SQL engine supports, builds a SQL clause that looks like either
"(a, b) > (?, ?)", or "(a > ?) OR (a == ? AND b > ?)".
Builds a SQL clause that looks like "(a, b) > (?, ?)"
Args:
database_engine
_database_engine
keys: A set of (column, value) pairs to be compared.
Returns:
A tuple of SQL query and the args
"""
if database_engine.supports_tuple_comparison:
return (
"(%s) > (%s)" % (",".join(k[0] for k in keys), ",".join("?" for _ in keys)),
[k[1] for k in keys],
)
# we want to build a clause
# (a > ?) OR
# (a == ? AND b > ?) OR
# (a == ? AND b == ? AND c > ?)
# ...
# (a == ? AND b == ? AND ... AND z > ?)
#
# or, equivalently:
#
# (a > ? OR (a == ? AND
# (b > ? OR (b == ? AND
# ...
# (y > ? OR (y == ? AND
# z > ?
# ))
# ...
# ))
# ))
#
# which itself is equivalent to (and apparently easier for the query optimiser):
#
# (a >= ? AND (a > ? OR
# (b >= ? AND (b > ? OR
# ...
# (y >= ? AND (y > ? OR
# z > ?
# ))
# ...
# ))
# ))
#
#
clause = ""
args = [] # type: List[KV]
for k, v in keys[:-1]:
clause = clause + "(%s >= ? AND (%s > ? OR " % (k, k)
args.extend([v, v])
(k, v) = keys[-1]
clause += "%s > ?" % (k,)
args.append(v)
clause += "))" * (len(keys) - 1)
return clause, args
return (
"(%s) > (%s)" % (",".join(k[0] for k in keys), ",".join("?" for _ in keys)),
[k[1] for k in keys],
)