locktable.sql

来自「derby database source code.good for you.」· SQL 代码 · 共 98 行

-- multiuser lock table tests
disconnect;

connect 'jdbc:derby:wombat;user=U1' AS C1;
autocommit off;
connect 'jdbc:derby:wombat;user=U2' AS C2;
autocommit off;

set connection C1;

-- create a table and populate it
create table t1 (c1 int);
insert into t1 values 1;
commit;

-- test TX vs TX locks
lock table u1.t1 in exclusive mode;

set connection C2;
lock table u1.t1 in exclusive mode;

set connection C1;
-- verify that we still have the lock
run resource 'LockTableQuery.subsql';

-- verify that we can insert into the table
insert into t1 values 2;
select * from t1;
commit;

-- test TX vs TS locks
lock table t1 in exclusive mode;

set connection C2;
lock table u1.t1 in share mode;

set connection C1;
-- verify that we still have the lock
run resource 'LockTableQuery.subsql';

-- verify that we can insert into the table
insert into t1 values 3;
select * from t1;
commit;

-- test TS vs TX locks
lock table t1 in share mode;

set connection C2;
lock table u1.t1 in exclusive mode;

set connection C1;
-- verify that we still have the lock
run resource 'LockTableQuery.subsql';

-- verify that we can insert into the table
insert into t1 values 4;
select * from t1;
commit;

-- test TS vs TS locks
lock table t1 in share mode;

set connection C2;
lock table u1.t1 in share mode;

set connection C1;
-- verify that we still have the lock
run resource 'LockTableQuery.subsql';

-- verify that we cannot insert into the table
insert into t1 values 5;
select * from t1;
commit;

set connection C2;
commit;

set connection C1;
-- create another table
create table t2(c1 int);
commit;
-- verify that user getting error on lock table doesn't get rolled back
lock table t1 in share mode;

set connection C2;
lock table u1.t2 in share mode;
lock table u1.t1 in exclusive mode;

set connection C1;
-- verify that other user still has the lock
run resource 'LockTableQuery.subsql';
commit;
disconnect;

set connection C2;
disconnect;