mariadb/mysql-test/main/unique.result

ALTER DATABASE test CHARACTER SET latin1 COLLATE latin1_swedish_ci;
CREATE TABLE t1 (pk INT AUTO_INCREMENT PRIMARY KEY, a varchar(30000), UNIQUE (a)) ENGINE=innodb;
INSERT INTO t1 (a) VALUES (20),(NULL),(NULL),(NULL),(NULL),(NULL),(NULL);
SELECT * FROM t1 WHERE a BETWEEN '1' AND '100';
pk	a
DROP TABLE t1;
CREATE TABLE t2 (n BLOB, UNIQUE(n));
INSERT INTO t2 VALUES (1);
DELETE FROM t2 WHERE n = 1;
DROP TABLE t2;
ALTER DATABASE test CHARACTER SET utf8mb4 COLLATE utf8mb4_uca1400_ai_ci;
CREATE TABLE t1 (c1 TEXT, UNIQUE (c1(1)));
SHOW CREATE TABLE t1;
Table	Create Table
t1	CREATE TABLE `t1` (
  `c1` text DEFAULT NULL,
  UNIQUE KEY `c1` (`c1`(1))
) ENGINE=MyISAM DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_uca1400_ai_ci
INSERT INTO t1 (c1) VALUES ('a');
SELECT 'abc' IN (SELECT c1 FROM t1);
'abc' IN (SELECT c1 FROM t1)
0
EXPLAIN format=json SELECT 'abc' IN (SELECT c1 FROM t1);
EXPLAIN
{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "No tables used"
    },
    "subqueries": [
      {
        "query_block": {
          "select_id": 2,
          "table": {
            "message": "Impossible WHERE noticed after reading const tables"
          }
        }
      }
    ]
  }
}
SELECT c1 FROM t1 WHERE ('abc' IN (SELECT c1 FROM t1)) IS FALSE;
c1
a
DROP TABLE t1;
CREATE TABLE t1 (c1 TEXT, c2 TEXT, UNIQUE (c1(1)));
SHOW CREATE TABLE t1;
Table	Create Table
t1	CREATE TABLE `t1` (
  `c1` text DEFAULT NULL,
  `c2` text DEFAULT NULL,
  UNIQUE KEY `c1` (`c1`(1))
) ENGINE=MyISAM DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_uca1400_ai_ci
INSERT INTO t1 (c1, c2) VALUES ('a','b');
SELECT ('abc', 'xyz') IN (SELECT c1, c2 FROM t1);
('abc', 'xyz') IN (SELECT c1, c2 FROM t1)
0
EXPLAIN format=json SELECT ('abc', 'xyz') IN (SELECT c1, c2 FROM t1);
EXPLAIN
{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "No tables used"
    },
    "subqueries": [
      {
        "query_block": {
          "select_id": 2,
          "table": {
            "message": "Impossible WHERE noticed after reading const tables"
          }
        }
      }
    ]
  }
}
SELECT * FROM t1 WHERE (('abc', 'xyz') IN (SELECT c1, c2 FROM t1)) IS FALSE;
c1	c2
a	b
DROP TABLE t1;
CREATE TABLE t1 (c1 TEXT, c2 TEXT, UNIQUE (c1(3)));
SHOW CREATE TABLE t1;
Table	Create Table
t1	CREATE TABLE `t1` (
  `c1` text DEFAULT NULL,
  `c2` text DEFAULT NULL,
  UNIQUE KEY `c1` (`c1`(3))
) ENGINE=MyISAM DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_uca1400_ai_ci
INSERT INTO t1 (c1, c2) VALUES ('abc','xyz');
SELECT ('abc', 'xyz') IN (SELECT c1, c2 FROM t1) IS FALSE;
('abc', 'xyz') IN (SELECT c1, c2 FROM t1) IS FALSE
0
EXPLAIN format=json SELECT ('abc', 'xyz') IN (SELECT c1, c2 FROM t1) IS FALSE;
EXPLAIN
{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "No tables used"
    },
    "subqueries": [
      {
        "query_block": {
          "select_id": 2,
          "const_condition": "(convert('abc' using utf8mb4) = 'abc' or 'abc' is null) and (convert('xyz' using utf8mb4) = 'xyz' or 'xyz' is null)",
          "having_condition": "'abc' is null and 'xyz' is null",
          "nested_loop": [
            {
              "table": {
                "table_name": "t1",
                "access_type": "system",
                "rows": 1,
                "filtered": 100
              }
            }
          ]
        }
      }
    ]
  }
}
SELECT * FROM t1 WHERE (('abc', 'xyz') IN (SELECT c1, c2 FROM t1)) IS FALSE;
c1	c2
SELECT ('abc', 'xyz') IN (SELECT c1, c2 FROM t1) IS TRUE;
('abc', 'xyz') IN (SELECT c1, c2 FROM t1) IS TRUE
1
EXPLAIN format=json SELECT ('abc', 'xyz') IN (SELECT c1, c2 FROM t1) IS TRUE;
EXPLAIN
{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "No tables used"
    },
    "subqueries": [
      {
        "query_block": {
          "select_id": 2,
          "const_condition": "(convert('abc' using utf8mb4) = 'abc' or 'abc' is null) and (convert('xyz' using utf8mb4) = 'xyz' or 'xyz' is null)",
          "having_condition": "'abc' is null and 'xyz' is null",
          "nested_loop": [
            {
              "table": {
                "table_name": "t1",
                "access_type": "system",
                "rows": 1,
                "filtered": 100
              }
            }
          ]
        }
      }
    ]
  }
}
SELECT * FROM t1 WHERE (('abc', 'xyz') IN (SELECT c1, c2 FROM t1)) IS TRUE;
c1	c2
abc	xyz
DROP TABLE t1;