[tarantool-patches] Re: [PATCH 9/9] sql: make <search condition> accept only boolean

[n.pettik]

>> <search condition> is a predicate used as a part of WHERE and
>> JOIN clauses. ANSI SQL states that <search condition> must
>> accept only boolean arguments. In our SQL it is implemented as
>> bytecode instruction OP_If which in turn carries out logic of
>> conditional jump. Since it can be involved in executing other routines
>> different from <search condition>, 
> 
> 1. Which other routines? What is a valid case of OP_If with non-boolean
> value in check?

For instance, to verify that register containing LIMIT value is > 0.
It is quite hard to track values which come to this opcode, so we
can’t be sure that it always accepts booleans.

>> we pass to it additional argument
>> when generating bytecode for WHERE and JOIN clauses. When VDBE performs
>> OP_If and detects such flag, it checks passed argument to be boolean.
>> 
>> Closes #3723
> 
> 2. In addition, it fixes https://github.com/tarantool/tarantool/issues/3651,
> doesn't it?

It does, added label.

>> diff --git a/test/sql-tap/e_delete.test.lua b/test/sql-tap/e_delete.test.lua
>> index a58dc87c7..374a7d3e4 100755
>> --- a/test/sql-tap/e_delete.test.lua
>> +++ b/test/sql-tap/e_delete.test.lua
>> @@ -89,15 +89,15 @@ test:do_delete_tests("e_delete-1.1", {
>> -- NULL are retained.
>> --
>> test:do_delete_tests("e_delete-1.2", {
>> -    {1, "DELETE FROM t3 WHERE 1       ; SELECT x FROM t3", {}},
>> -    {2, "DELETE FROM t4 WHERE 0  ; SELECT x FROM t4", {1, 2, 3, 4, 5}},
>> -    {3, "DELETE FROM t4 WHERE 0.0     ; SELECT x FROM t4", {1, 2, 3, 4, 5}},
>> +    {1, "DELETE FROM t3 WHERE true       ; SELECT x FROM t3", {}},
>> +    {2, "DELETE FROM t4 WHERE false  ; SELECT x FROM t4", {1, 2, 3, 4, 5}},
>> +    {3, "DELETE FROM t4 WHERE false    ; SELECT x FROM t4", {1, 2, 3, 4, 5}},
> 
> 3. The last two lines are exactly the same. Why not to drop one?

Ok, dropped.

>>     {4, "DELETE FROM t4 WHERE NULL    ; SELECT x FROM t4", {1, 2, 3, 4, 5}},
>>     {5, "DELETE FROM t4 WHERE y!='two'; SELECT x FROM t4", {2}},
>>     {6, "DELETE FROM t4 WHERE y='two' ; SELECT x FROM t4", {}},
>>     {7, "DELETE FROM t5 WHERE x=(SELECT max(x) FROM t5);SELECT x FROM t5", {1, 2, 3, 4}},
>>     {8, "DELETE FROM t5 WHERE (SELECT max(x) FROM t4)  ;SELECT x FROM t5", {1, 2, 3, 4}},
>> -    {9, "DELETE FROM t5 WHERE (SELECT max(x) FROM t6)  ;SELECT x FROM t5", {}},
>> +    {9, "DELETE FROM t5 WHERE (SELECT max(x) FROM t6) != 0  ;SELECT x FROM t5", {}},
>>     {10, "DELETE FROM t6 WHERE y>'seven' ; SELECT y FROM t6", {"one", "four", "five"}},
>> })
>> 
>> diff --git a/test/sql-tap/e_select1.test.lua b/test/sql-tap/e_select1.test.lua
>> index 970eeeed9..e47b0f43d 100755
>> --- a/test/sql-tap/e_select1.test.lua
>> +++ b/test/sql-tap/e_select1.test.lua
>> @@ -448,15 +448,15 @@ test:do_select_tests(
>> -- true are included from the dataset.
>> --
>> local data ={
>> -    {"1"," SELECT * FROM t1 JOIN_PATTERN t2 ON (1) ",t1_cross_t2},
>> -    {"2"," SELECT * FROM t1 JOIN_PATTERN t2 ON (0) ",{}},
>> +    {"1"," SELECT * FROM t1 JOIN_PATTERN t2 ON (true) ",t1_cross_t2},
>> +    {"2"," SELECT * FROM t1 JOIN_PATTERN t2 ON (false) ",{}},
>>     {"3"," SELECT * FROM t1 JOIN_PATTERN t2 ON (NULL) ",{}},
>> -    {"6"," SELECT * FROM t1 JOIN_PATTERN t2 ON (0.9) ",t1_cross_t2},
>> -    {"7"," SELECT * FROM t1 JOIN_PATTERN t2 ON ('0.9') ",t1_cross_t2},
>> -    {"8"," SELECT * FROM t1 JOIN_PATTERN t2 ON (0.0) ",{}},
>> +    {"6"," SELECT * FROM t1 JOIN_PATTERN t2 ON (true) ",t1_cross_t2},
>> +    {"7"," SELECT * FROM t1 JOIN_PATTERN t2 ON (true) ",t1_cross_t2},
>> +    {"8"," SELECT * FROM t1 JOIN_PATTERN t2 ON (true) ",t1_cross_t2},
> 
> 4. The same. 3 duplicates.

Removed duplicates.