CREATE TABLE t1(a INT, b STRING, c TIMESTAMP TIME INDEX);

Affected Rows: 0

INSERT INTO t1 VALUES (41, "hello", 1), (42, "world", 2), (43, "greptime", 3);

Affected Rows: 3

CREATE VIEW v1 AS SELECT a, b FROM t1;

Affected Rows: 0

SELECT * FROM v1;

+----+----------+
| a  | b        |
+----+----------+
| 41 | hello    |
| 42 | world    |
| 43 | greptime |
+----+----------+

SELECT a FROM v1;

+----+
| a  |
+----+
| 41 |
| 42 |
| 43 |
+----+

INSERT INTO t1 VALUES (44, "greptimedb", 4);

Affected Rows: 1

SELECT * FROM v1;

+----+------------+
| a  | b          |
+----+------------+
| 41 | hello      |
| 42 | world      |
| 43 | greptime   |
| 44 | greptimedb |
+----+------------+

SHOW CREATE VIEW v1;

+------+---------------------------------------+
| View | Create View                           |
+------+---------------------------------------+
| v1   | CREATE VIEW v1 AS SELECT a, b FROM t1 |
+------+---------------------------------------+

CREATE OR REPLACE VIEW v1 AS SELECT a, b, c FROM t1 WHERE a > 43;

Affected Rows: 0

SHOW CREATE VIEW v1;

+------+------------------------------------------------------------------+
| View | Create View                                                      |
+------+------------------------------------------------------------------+
| v1   | CREATE OR REPLACE VIEW v1 AS SELECT a, b, c FROM t1 WHERE a > 43 |
+------+------------------------------------------------------------------+

SELECT * FROM v1;

+----+------------+-------------------------+
| a  | b          | c                       |
+----+------------+-------------------------+
| 44 | greptimedb | 1970-01-01T00:00:00.004 |
+----+------------+-------------------------+

--- if not exists, so it doesn't change at all ---
CREATE VIEW IF NOT EXISTS v1 AS SELECT c FROM t1;

Affected Rows: 0

SHOW CREATE VIEW v1;

+------+------------------------------------------------------------------+
| View | Create View                                                      |
+------+------------------------------------------------------------------+
| v1   | CREATE OR REPLACE VIEW v1 AS SELECT a, b, c FROM t1 WHERE a > 43 |
+------+------------------------------------------------------------------+

SELECT * FROM v1;

+----+------------+-------------------------+
| a  | b          | c                       |
+----+------------+-------------------------+
| 44 | greptimedb | 1970-01-01T00:00:00.004 |
+----+------------+-------------------------+

--- if not exists with replace, so it changes ---
CREATE OR REPLACE VIEW IF NOT EXISTS v1 AS SELECT c FROM t1;

Error: 1004(InvalidArguments), Invalid SQL, error: syntax error Create Or Replace and If Not Exist cannot be used together

SHOW CREATE VIEW v1;

+------+------------------------------------------------------------------+
| View | Create View                                                      |
+------+------------------------------------------------------------------+
| v1   | CREATE OR REPLACE VIEW v1 AS SELECT a, b, c FROM t1 WHERE a > 43 |
+------+------------------------------------------------------------------+

SELECT * FROM v1;

+----+------------+-------------------------+
| a  | b          | c                       |
+----+------------+-------------------------+
| 44 | greptimedb | 1970-01-01T00:00:00.004 |
+----+------------+-------------------------+

DROP VIEW v1;

Affected Rows: 0

DROP TABLE t1;

Affected Rows: 0

SHOW CREATE VIEW v1;

Error: 4001(TableNotFound), View not found: v1