From 6aefda7185fc8a1e80dd8daa98d3d0a6fd860068 Mon Sep 17 00:00:00 2001
From: Denis Smirnov <sd@picodata.io>
Date: Mon, 20 Jun 2022 20:36:49 +0700
Subject: [PATCH] fix: default result parameter type
Problem description.
When we prepare a statement with parameters in the result columns
(for example box.prepare('select ?')) Tarantool has no information
about the type of the output column and set it to default boolean.
Then, on the execution phase, the type would be recalculated during
the parameter binding.
Tarantool expects that there is no way for parameter to appear in the
result tuple other than exactly be mentioned in the final projection.
But it is incorrect - we can easily propagate parameter from the inner
part of the join. For example
box.prepare([[select COLUMN_1 from t1 join (values (?)) as t2 on true]])
In this case column COLUMN_1 in the final projection is not a
parameter, but a "reference" to it and its type depends on the
parameter from the inner part of the join. But as Tarantool
recalculates only binded parameters in the result projection,
it doesn't change the default boolean metadata type of the COLUMN_1
and the query fails on comparison with the actual type of the tuple.
Solution.
As we don't want to patch Vdbe to make COLUMN_1 refer inner parameter,
it was decided to make a simple workaround: change the default
column type from BOOLEAN to ANY for parameters. It fixes the
comparison with the actual tuple type (we do not fail), but in some
cases get ANY column in the results where we would like to have
explicitly defined type. Also NULL parameters would also have ANY
type, though Tarantool prefers to have BOOLEAN in this case.
Closes https://github.com/tarantool/tarantool/issues/7283
NO_DOC=bug fix
---
.../gh-7283-result-parameter-type.md | 3 +++
src/box/sql/expr.c | 8 ++++++-
.../gh_7283_result_parameter_type_test.lua | 23 +++++++++++++++++++
test/sql/bind.result | 2 +-
4 files changed, 34 insertions(+), 2 deletions(-)
create mode 100644 changelogs/unreleased/gh-7283-result-parameter-type.md
create mode 100644 test/sql-luatest/gh_7283_result_parameter_type_test.lua
diff --git a/changelogs/unreleased/gh-7283-result-parameter-type.md b/changelogs/unreleased/gh-7283-result-parameter-type.md
new file mode 100644
index 0000000000..f31556cfb3
--- /dev/null
+++ b/changelogs/unreleased/gh-7283-result-parameter-type.md
@@ -0,0 +1,3 @@
+## bugfix/sql
+
+Fixes a failing inner join query, projecting parameters from the inner table to the result projection. As a side effect the default column metadata was changed from `boolean` to `any` type.
diff --git a/src/box/sql/expr.c b/src/box/sql/expr.c
index b5aa42ff1e..c1226a151a 100644
--- a/src/box/sql/expr.c
+++ b/src/box/sql/expr.c
@@ -1300,7 +1300,13 @@ expr_new_variable(struct Parse *parse, const struct Token *spec,
len += id->n;
}
struct Expr *expr = sql_expr_new_empty(TK_VARIABLE, len + 1);
- expr->type = FIELD_TYPE_BOOLEAN;
+ if (expr == NULL)
+ return NULL;
+ if (spec->n == 1 && spec->z[0] == '?') {
+ expr->type = FIELD_TYPE_ANY;
+ } else {
+ expr->type = FIELD_TYPE_BOOLEAN;
+ }
expr->flags = EP_Leaf;
expr->u.zToken = (char *)(expr + 1);
expr->u.zToken[0] = spec->z[0];
diff --git a/test/sql-luatest/gh_7283_result_parameter_type_test.lua b/test/sql-luatest/gh_7283_result_parameter_type_test.lua
new file mode 100644
index 0000000000..56fcf65701
--- /dev/null
+++ b/test/sql-luatest/gh_7283_result_parameter_type_test.lua
@@ -0,0 +1,23 @@
+local server = require('luatest.server')
+local t = require('luatest')
+local g = t.group()
+
+g.before_all(function()
+ g.server = server:new({alias = 'result_parameter_type'})
+ g.server:start()
+end)
+
+g.after_all(function()
+ g.server:stop()
+end)
+
+g.test_result_parameter_type_1 = function()
+ g.server:exec(function()
+ local t = require('luatest')
+ box.execute([[CREATE TABLE t1(a INT PRIMARY KEY);]])
+ local q = box.prepare([[SELECT COLUMN_1 FROM t1 JOIN (VALUES (?)) AS t2 ON true]])
+ local res, _ = q:execute()
+ t.assert_equals(res.metadata[1].type, 'any')
+ box.execute([[DROP TABLE t1;]])
+ end)
+end
diff --git a/test/sql/bind.result b/test/sql/bind.result
index 3b4e8cbe78..08486c020e 100644
--- a/test/sql/bind.result
+++ b/test/sql/bind.result
@@ -166,7 +166,7 @@ execute('SELECT :value3, ?, :value1, ?, ?, @value2, ?, :value3', parameters)
- name: COLUMN_6
type: integer
- name: COLUMN_7
- type: boolean
+ type: any
- name: COLUMN_8
type: boolean
rows:
--
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