After changing behavior of the `IS` operator (#b3a3ddb571),
`SET NULL` was rewritten to use `EQ` instead. Which do not respect
NULLs.
This commit fixes the null related behavior by emitting logical
constructions equivalent for this case to old `IS`.
Those constructions are not equal to the old `EQ` in common case.
Before:
`oldval` old_is `newval`
Now:
`oldval` is_null or (`newval` is_not_null and `oldval` eq `newval`)
Closes #3645
---
Issue: https://github.com/tarantool/tarantool/issues/3645
Branch: https://github.com/tarantool/tarantool/tree/kh/gh-3642-set-null
src/box/sql/fkey.c | 49 ++++++++++++++------
test/sql-tap/gh3645-set-null.test.lua | 84 +++++++++++++++++++++++++++++++++++
2 files changed, 119 insertions(+), 14 deletions(-)
create mode 100755 test/sql-tap/gh3645-set-null.test.lua
diff --git a/src/box/sql/fkey.c b/src/box/sql/fkey.c
index 091778fc8..0abf42c84 100644
--- a/src/box/sql/fkey.c
+++ b/src/box/sql/fkey.c
@@ -787,24 +787,45 @@ fkey_action_trigger(struct Parse *pParse, struct Table
*pTab, struct fkey *fkey,
/*
* For ON UPDATE, construct the next term of the
- * WHEN clause. The final WHEN clause will be like
+ * WHEN clause, which should return false in case
+ * there is a reason to for a broken constrant in
+ * a parent table:
+ * no_action_needed := `oldval` IS NULL OR
+ * (`newval` IS NOT NULL AND
+ * `newval` = `oldval`)
+ *
+ * The final WHEN clause will be like
* this:
*
- * WHEN NOT(old.col1 = new.col1 AND ... AND
- * old.colN = new.colN)
+ * WHEN NOT( no_action_needed(col1) AND ...
+ * no_action_needed(colN))
*/
if (is_update) {
- struct Expr *l, *r;
- l = sqlite3PExpr(pParse, TK_DOT,
- sqlite3ExprAlloc(db, TK_ID, &t_old, 0),
- sqlite3ExprAlloc(db, TK_ID, &t_to_col,
- 0));
- r = sqlite3PExpr(pParse, TK_DOT,
- sqlite3ExprAlloc(db, TK_ID, &t_new, 0),
- sqlite3ExprAlloc(db, TK_ID, &t_to_col,
- 0));
- eq = sqlite3PExpr(pParse, TK_EQ, l, r);
- when = sqlite3ExprAnd(db, when, eq);
+ Expr *old_val = sqlite3PExpr(
+ pParse, TK_DOT,
+ sqlite3ExprAlloc(db, TK_ID, &t_old, 0),
+ sqlite3ExprAlloc(db, TK_ID, &t_to_col,
+ 0));
+ Expr *newVal = sqlite3PExpr(
+ pParse, TK_DOT,
+ sqlite3ExprAlloc(db, TK_ID, &t_new, 0),
+ sqlite3ExprAlloc(db, TK_ID, &t_to_col,
+ 0));
+ Expr *old_is_null = sqlite3PExpr(
+ pParse, TK_ISNULL,
+ sqlite3ExprDup(db, old_val, 0), NULL);
+ eq = sqlite3PExpr(
+ pParse, TK_EQ,
+ sqlite3ExprDup(db, old_val, 0),
+ sqlite3ExprDup(db, newVal, 0));
+ Expr *new_non_null = sqlite3PExpr(
+ pParse, TK_NOTNULL, newVal, NULL);
+ Expr *non_null_eq = sqlite3PExpr(
+ pParse, TK_AND, new_non_null, eq);
+ Expr *no_action_needed = sqlite3PExpr(
+ pParse, TK_OR, old_is_null,
+ non_null_eq);
+ when = sqlite3ExprAnd(db, when, no_action_needed);
}
if (action != FKEY_ACTION_RESTRICT &&
diff --git a/test/sql-tap/gh3645-set-null.test.lua
b/test/sql-tap/gh3645-set-null.test.lua
new file mode 100755
index 000000000..9067c52f1
--- /dev/null
+++ b/test/sql-tap/gh3645-set-null.test.lua
@@ -0,0 +1,84 @@
+#!/usr/bin/env tarantool
+test = require("sqltester")
+test:plan(11)
+
+test:do_catchsql_test(
+ "set-null-1.0",
+ [[
+ CREATE TABLE T1 (a INTEGER PRIMARY KEY,
+ b char(5) unique);
+ CREATE TABLE T2 (a INTEGER PRIMARY KEY,
+ b char(5) unique,
+ foreign key (b) references t1 (b) on update set null);
+ INSERT INTO T1 VALUES (1,'a');
+ INSERT INTO T2 VALUES (1,'a');
+ ]], {0});
+
+test:do_catchsql_test(
+ "set-null-1.1",
+ [[
+ UPDATE T1 SET B = NULL;
+ ]], {0});
+
+test:do_catchsql_test(
+ "set-null-1.2",
+ [[
+ SELECT * FROM T1;
+ ]], {0, {1, ""}});
+
+test:do_catchsql_test(
+ "set-null-1.3",
+ [[
+ SELECT * FROM T2;
+ ]], {0, {1, ""}});
+
+test:do_catchsql_test(
+ "set-null-1.4",
+ [[
+ UPDATE T1 SET B = 'a';
+ ]], {0});
+
+test:do_catchsql_test(
+ "set-null-1.5",
+ [[
+ SELECT * FROM T1;
+ ]], {0, {1, "a"}});
+
+test:do_catchsql_test(
+ "set-null-1.6",
+ [[
+ SELECT * FROM T2;
+ ]], {0, {1, ""}});
+
+
+test:do_catchsql_test(
+ "set-null-2.0",
+ [[
+ CREATE TABLE T3 (a INTEGER PRIMARY KEY,
+ b char(5) unique);
+ CREATE TABLE T4 (a INTEGER PRIMARY KEY,
+ b char(5) unique,
+ foreign key (b) references t3 (b) on update cascade);
+ INSERT INTO T3 VALUES (1,'a');
+ INSERT INTO T4 VALUES (1,'a');
+ ]], {0});
+
+test:do_catchsql_test(
+ "set-null-2.1",
+ [[
+ UPDATE T3 SET B = 'b';
+ ]], {0});
+
+test:do_catchsql_test(
+ "set-null-2.2",
+ [[
+ SELECT * FROM T3;
+ ]], {0, {1, "b"}});
+
+test:do_catchsql_test(
+ "set-null-2.3",
+ [[
+ SELECT * FROM T4;
+ ]], {0, {1, "b"}});
+
+test:finish_test()
--
2.14.1
